Any craft made from natural material is always a revelation for the one who creates it. Collecting something new and unusual from familiar and boring objects, embodying your ideas with the help of cones, twigs and fruits of an interesting shape can be so exciting that adults are also involved in the lesson. At the same time, the child receives a lot of positive emotions both from the new game and from communicating with dear people.
Any craft made from natural material is always a revelation for the one who creates it.
The undeniable benefit of constructing funny toys and beautiful panels from natural material with your own hands is to stimulate imagination and spatial thinking. When working with small details, the child develops finger motor skills, which also affects the development of the brain. But the most important thing for loving parents is the pleasure that the baby gets in the process of creating another homemade product.
Nature itself provides a huge amount of what is useful for a useful game. Among the details of a future toy or a panel made of natural material, there may be gifts from the autumn forest, sea shells from summer beaches, and beautiful pebbles found in the sandbox. Seeds and fruits of cultivated plants in a garden or park should not be ignored: they are no less diverse than forest treasures.
In addition to the natural material itself, it may be useful:
- thin strong sticks (toothpicks, skewers, matches) for connecting parts;
- wire;
- curved branches;
- paints and brush;
- plasticine;
- cardboard or plywood;
- scissors;
- awl.
Nature itself provides a huge amount of what is useful for a useful game. If autumn leaves are needed to create a composition, then it is best to dry them first. Otherwise, they are deformed, and a picture made of natural material will lose all its decorative effect. To dry, the leaves are placed between layers of newsprint, covered with a flat board and pressed with a small load. After a few days, the leaves will dry completely, remaining as colorful and even as when fresh.
Gallery: crafts from natural material (25 photos)
Applications with a baby (video)
Funny toys for kids
Souvenirs from natural material can be easily created by a child of both preschool and primary school age. Adults should only show how to fasten the parts of the craft. For rigid connections it is better to use short pointed sticks, and movable and curved necks, tails and limbs can be made of thick copper wire.
The main motive of toys made of natural material is animals. They can look like real animals or take on the appearance of anthropomorphic cartoon characters. Some products can even serve as Christmas decorations if they are hung on a ribbon or thread.
Large and expressive souvenirs can be made from spruce and pine cones:
- The craft "Squirrel on a Pine" is assembled from 3 cones of different sizes. The largest, spruce, will be required for a lush tail. It is very good if it is slightly curved. It is required to pierce the base of this part with a stick and attach it to the base of a smaller cone, which will serve as the body of the animal. The head can be made from a small pine or larch cone, from a rounded acorn. This part must be attached by means of a pointed stick to the upper end of the body. For strength, you can glue the parts. Maple lionfish or ash seeds work well for animal ears. They must be firmly inserted between the scales of the cone or driven into punctured holes in the stomach. Paws cut out of felt, made of wire or crooked twigs. For the eyes, use shiny forest peony seeds, cherry pits, or similar materials. Pick up a pine log with a protruding knot and attach a small pine branch to it. Put the squirrel on a knot and decorate the craft with cones, autumn leaves or artificial snow.
- The turtle is even easier to make: you need 1 large open pine cone and an acorn for the head. At the cone, you need to remove the upper part so that a semicircular base remains. Stick a curved branch or piece of wire into the cone, and fix the acorn at the other end. The legs of a sea turtle perfectly imitate maple lionfish.
- A goldfish from a rounded cone can decorate a Christmas tree. It is enough to glue large eyes from beads or acorn caps to the cone, and use bird feathers for the veil tail and fins, coloring them in gold.
Interesting crafts from cones can be very diverse. Their manufacture requires from 1 to several parts of different sizes and all kinds of related elements: seeds, feathers, needles.
Souvenirs from natural material can be easily created by a child of both preschool and primary school age How are stick insects made?
Do-it-yourself autumn crafts are simple, but amazing in variety, insects on sticks. You can bring them to kindergarten or school, give them to friends or your favorite teacher. Making them takes quite a bit of time, but they are very elegant both on their own and in composition with a bouquet of leaves.
You will need long thin skewers for barbecue and dried large seeds and fruits of an interesting shape. Glue a double maple lionfish to a stick at the junction of 2 seeds. Draw the eyes and color the "wings" with colored nail polish.
From the horned and prickly seeds of the string, burdock, buttercup, you can make charming beetles, spiders and butterflies. They will have to glue the legs or wings. You can also create beautiful flowers from boxes of nigella, poppy, snapdragon, putting them on a stick and supplementing them with petals from lionfish, maple, ash or physalis shells and small leaves.
Autumn crafts made from natural material (video)
How to make a panel from natural material?
A common type of craft made from natural material for elementary school and senior groups kindergarten- paintings from various elements of natural origin. A voluminous landscape, various bouquet autumn compositions made of natural materials with your own hands can be made both on a rigid cardboard base, and in the form of a topiary or a wreath. In this case, glue is often used to connect the parts.
A composition of shells on a marine theme can remind you of the serene days of a summer vacation by the sea. Thick cardboard is suitable as a basis. To make a panel with a boat, you need 1 large rapana shell for its body and a lot of flat doors of different sizes.
Plasticine or thin wire may be required to firmly connect an uneven sink to the base. Carefully examining the rapana, you can see that it resembles the convex side of a sea vessel. You need to attach it with a hole to the base. You can make lower sails from larger flaps by placing shells directly above the hull. Moving up, you should choose smaller sashes. When the boat is ready, you need to draw waves around it with gouache, paint the sky blue. Instead of paint, you can use tinted semolina: it lays unevenly on cardboard smeared with glue, successfully imitating waves.
After the paint has dried, you can continue decorating the panel: make decorations in the form of pearls and starfish lying at the bottom, algae from twisted blades of grass, sea turtles from walnut shells. There should be no limits to fantasy here. For a real artist, the material itself suggests ideas.
Autumn paintings from seeds and leaves
Grade 1 students and pupils of the preparatory group have a tradition: to celebrate the beginning of the school year with a matinee and the creation of competitive crafts and panels from natural materials on the theme "Autumn". Pictures can be made on the basis of cardboard, painted in shades of yellow. You can also decorate the base with burlap or sisal.
Flowers for such compositions are often collected from various seeds: pumpkin seeds, sunflower, corn. Planar paintings can be made by simply gluing a few seeds around the central element. Alternating randomly large and small corollas, it is easy to create a bouquet to your taste.
The large flowers are very beautiful. They can be made from the same seeds, but glued to the base with a sharp end. For fastening, it is better to use plasticine: roll up the ball and press it firmly against the base. It is very easy to stick seeds or feathers into soft material. Lush roses can be made from the shells, placing them in this order:
- attach 2 sashes side by side, slightly opening them;
- glue 1 shell perpendicular to the gap between the wings;
- install 2-3 more pieces around the initial elements, shifting them so that these wings overlap the connections of the previous ones.
By increasing the number of rows of petals, you need to select larger shells. You can complement the bouquet with bright leaves, which autumn is so rich in, colored linden seeds, make a vase or basket of acorns or colored beans.
To create a decorative wreath "Autumn" you will need some thin branches (birch, for example) or straw. Having collected the material in a bundle, braided it or simply twisted it several times, you need to fix it with a thin wire and connect the ends. The resulting ring will serve as the basis of the composition.
You can decorate a wreath with dried flowers and leaves, physalis fruits, decorative pumpkins of a suitable size, hop cones. The wealth of material that autumn itself bestows on the artist will help to make a colorful souvenir for her holiday. It is important not to limit the flight of your imagination.
Topiary from seeds
Crafts from natural material for children of primary school age on the theme "Golden Autumn" can also be made in the form of a three-dimensional tree, reinforced on the base. Often a small pot or glass is used for this. A trunk from a straight or curved branch can be fixed by filling the base with plasticine. Put a ball rolled up from newsprint on the upper end.
All parts need to be decorated. The base can be pasted over with multi-colored seeds (beans, soybeans, peas and beans). Bright autumn leaves can bloom on the trunk, it is permissible to wrap it around with flexible stems of hops or loaches or decorate it to your taste.
The most colorful is the topiary crown. Seed flowers, painted poppy pods, acorns, nuts, cones will give you the opportunity to express your vision of autumn as a season of abundance. You can complement the decor with various forest vegetation: dry leaves of marin root boxes, tinder fungi of an unusual shape (in the form of a rose, for example), fern leaves, moss, bright rose hips. It will be very pleasant for both the child and the mother to take such a craft to the kindergarten.
When designing, the baby sometimes cannot cope with the material. It is important that he is not left alone during the lesson: by providing help in time, adults are able to support his interest in an exciting game.
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Product: "Wise Owl".
Tasks and materials in the workbook: "Figures from natural material."
Lesson objectives: repeat information about the types of natural materials; determine the properties of some natural materials in terms of shape, strength; introduce the method of connecting parts - on plasticine; learn to design a product from natural material by connecting parts with plasticine; to form the ability to analyze the product on the basis of the proposed criteria (using the rubric "Questions of a young technologist"); to develop the ability to organize their activities: to learn to plan practical activities (selection of necessary materials, drawing up a work plan), to cultivate a respect for nature.
Planned results:
Subject: distinguish between types of natural materials; compare the properties of natural materials (shape, strength); be able to select the necessary materials for the manufacture of the product; evaluate the results of its activities on the basis of sub-questions; understand the importance of caring for nature
Personal: careful attitude to the world around, understanding the main criteria for evaluating one's activities based on the criteria specified in the textbook and answers to the "Questions of a young technologist".
Regulatory: be able to carry out the action according to the model, carry out work on the basis of the slides and text plans presented in the textbook; mastering the method of manufacturing a product from natural materials based on a compound on plasticine; ability to control one's performance
Cognitive: to analyze the object in order to highlight the essential features (features of the appearance of an owl);
Communicative: development of the ability to jointly discuss the stated issues; listen and hear the teacher, classmates; the ability to explain your choice.
Basic terms and concepts: sketch, composition.
Resources and equipment.
At the teacher: textbook, workbook, natural materials; plasticine, options for the finished product, photographs, sketches of an owl, materials for playing a game to draw up an image of an owl; materials and tools for the manufacture of the product.
For students: textbook, workbook, oilcloth, stack, napkin, natural materials (cones, maple seeds, acorn caps, oak leaves, twig), plasticine, peppercorns, two persimmon seeds (can be replaced with plasticine).
During the classes:
Introductory part(4 min.).
The lesson begins with a discussion of the topic of the last lesson. Students can demonstrate the products that they brought from home, at such an exhibition there is a repetition of the material (plasticine properties; working methods; working rules). Since the practical work will also be related to natural materials, it is worth repeating the material about the types of natural materials here. Offer to consider the following natural materials and compare according to some properties (shape, strength): cones, maple seeds, acorn caps, oak leaves.
Teacher: “Today you brought various materials to the lesson that you collected in the park or in the forest. Can you tell me what collection rules you followed? Why do you think it is so important to follow these rules? Students explain what rules for collecting natural materials must be observed. They also talk about the need to respect nature. Trees grow very slowly, the state protects the forests, and we also need to take good care of them and not spoil the trees.
Teacher: “In the last two lessons, we made two products, before starting work, we analyzed the product and planned our work. Today we will get acquainted with the questions of a young technologist, which we will answer before manufacturing each product. But first, guess the riddle of who we will do today.
Product analysis. Work planning.(7 min.)
Teacher: “On page 22, under the “We work independently” sign, we are invited to complete the “Wise Owl” product. Pay attention to the signs of the complexity of execution and the cost of time. How difficult is the execution of this product? (difficult, there will be new methods of work). How long will it take to make this product? (the authors suggest that the craft must be completed at home, that is, it must be done for a long time). Let's see, at the end of the lesson, how difficult it really is to make this product and how much time we will spend on making it.
What is an owl called? (wise). Let's look at the owl carefully in the photographs (drawings), describe it.
The students look at the picture of the owl in the photographs and describe it.
Large head, large round eyes surrounded by a facial disc, beak short and curved. The plumage is dense and soft, the tail is rectangular, and the wings are relatively large, rounded, the color of the plumage of owls is usually "protective", that is, it blends into the environment, helping the owl to remain unnoticed during daytime rest. Feathers of forest owls are usually brownish, while species living in coniferous forests have a grayish tint, feathers cover the paws, and their claws are all long and sharp.
Teacher: "We will make an owl from natural materials, let's make an assumption about what natural materials can be used to make an owl."
Students express their opinion on what kind of natural material should be taken to depict the torso, paws, eyes, eyebrows, wings, nose.
You can also visually demonstrate what is obtained from the materials that students offer. Children offer a type of natural material for the body, the teacher demonstrates the selected material; further, what we choose for the manufacture of paws - paws appear, etc. For this game, you can use both natural materials themselves and enlarged models of individual parts, you can also use the possibilities of electronic resources.
After the teacher demonstrates the product to be performed in the lesson.
The teacher invites students to answer the questions of the young technologist presented on page 21 of the textbook. Children examine the product, as well as the slides in the textbook on page 23, and answer the questions of the young technologist. If there are difficulties in answering questions, the teacher makes explanations or asks leading questions. The teacher leads the students to the answers presented in the textbook on pages 22-23, also commenting on them.
1. What will I do? (I will make an owl).
At this stage, we answer the question of what product we will produce, you can immediately give the name of our work. What is the name of our product? (Wise Owl). Also here we have to carry out sketches of our future works. What is a sketch? Students assume that this is a preliminary drawing, a sketch. In the sketch, we try to recreate the product that we would like to make.
Here the teacher can demonstrate several variations of the owl sketch.
2. What materials and tools will I need to work? (I will need natural materials: cones, maple seeds, acorn caps, oak leaves). What is the body, eyes, wings, eyebrows made of? What is the owl sitting on?
It turns out the whole composition. What is composition? (mutual arrangement of parts). That is, this is a work in which all components (details) are connected by one idea. What is our idea? (the owl sits in the forest on a branch).
3. How will I do the work? In what ways? (I will connect the details with plasticine).
How are the parts connected in this product? (on plasticine). This is the easiest way to connect - using plasticine, we roll a small ball, attach it to a part and attach it to another part (the teacher demonstrates this technique).
4. What will I do first, then what? (I will draw up a work plan or get acquainted with the finished one). We will work according to the plan presented in the tutorial. But at the same time, students can be invited to draw up a work plan for making an owl. In this case, the work plan can be made up of three points of the plan:
1) Organization of the workplace.
2) Connecting parts with plasticine.
3) Product design.
5. Why will I make this product? (You can give an owl to a friend or decorate your desktop with this craft).
6. I will summarize my work. (What happened, what should be learned?). The teacher informs that the students will give the answer to this question during the debriefing, when they put their work on the exhibition.
Product manufacturing. (20-25 min.)
Practical work takes place in the same way as in the previous lesson, students will compare the text and slide plan, do the work under the guidance of the teacher. During practical work, the teacher pays attention to the quality of the work performed: stick the details carefully, do not take too much plasticine so that it is not visible behind the details, compare your work with the teacher's sample.
Depending on the capabilities of the class, students can be asked to complete the product on their own, focusing on some operations that may cause difficulties. In this case, answering the questions of a young technologist ”in paragraph 4, consider in detail two work plans: test and slide.
1. I organize my workplace. Let's take a look at slide #1.
Students list the materials, tools, devices that they see on the slide and check their presence on their tables.
The teacher notes that this point of the plan coincides with the one drawn up by the students.
2. Break off the top of the big bump.
Students, looking at slide number 2, note that a small part needs to be broken off.
The teacher notes that this point of the plan was not planned for the students.
Before turning to the next points of the plan, the teacher notes that further work will be done on connecting parts with plasticine (the same point in the plan as for students), but the description in the textbook is given in more detail.
3. I will stick two small cones with plasticine - the legs of an owl turned out.
Slide number 3 shows where you need to stick small cones, for this you need small pieces of plasticine.
The teacher attaches plasticine to small cones and sticks them to the big one.
4. I will make eyes for an owl. To do this, I will attach pepper peas inside the acorn cap with plasticine.
Let's see how this action is shown on slide #4. Students explain what is shown on the slide, they also note that persimmon bones are also prepared here, they make suggestions for what they are depicted (how to make a nose is shown).
5. I will stick my eyes to the head of an owl. From plasticine or two persimmon seeds I will make a beak and also stick it to the owl's head.
See what a cute owl turns out on slide number 5. How to connect two persimmon seeds? Which slide shows this?
Students complete this activity on their own.
6. I will stick maple lionfish over the eyes of an owl with plasticine - the owl frowned.
Did the owl really furrow its brows? Let's look at slide #6. How are the wings attached? How else can you stick? Students offer their own options, describe how they see an owl.
7. I will stick two oak leaves with plasticine to my back, placing them under the scales of the cone - I will get wings.
How are the leaves attached to the bump on slide number 7? Students pay attention that the leaves need to be stuck on plasticine, while you need to put them under the scales of the cone.
So, our owl is ready. In our plan, there is one more point - this is the design of the product. In the textbook, it is represented by point 8.
8. I will put an owl on a branch.
Students look at slide #8.
Here the teacher can offer each student to draw up their work individually: you can put an owl on a twig, you can decorate a twig, add plasticine or stick leaves on a twig, as if the owl is hiding. Another option is also possible: to do collective work. The teacher can prepare several branches and invite students to plant owls on them, you get a whole family (each student can leave a piece of paper with his name under his owl or come up with a name for the owl).
Let's summarize.(5 minutes).
At this stage there is an exhibition of works. Here, students are invited to answer the last question of the "Questions of a young technologist": Let me summarize my work. What happened, what should be learned? Students note that they have learned to compose a composition from natural materials, to connect parts using plasticine.
They also evaluate their products: is the product made neatly, or do you still need to work on the product. The teacher can invite students to choose the smartest owl, the most surprised, the kindest, the most serious, etc. Students can choose multiple candidates, but at the same time explaining their choice.
Teacher: “A huge number of figurines can be made from natural material. Open your workbook to page 11 “Natural figurines”, who do you recognize? (bird, cockerel, dragon, hedgehog).
At home, you can make your favorite figurine.
The electronic application for the lesson consists of 4 sections: "New Material", "Check Yourself", "Video", "Do It Yourself".
We suggest working through the "New Material" section at the end of the introductory part of this lesson. Here, children will find themselves in the forest, hear the voices of birds and learn useful information about the owl.
Next, you can refer to the "Check Yourself" section. The game "Guess the bird by its voice" will remind the children about the variety of birds in the forest and motivate them for further work. An interesting addition to the analysis of the product will be the "Materials" tab from the "Do It Yourself" section. In it you will find information about the types of natural material needed to make the product and introduce students to the variety of cones.
The key factor determining the fire hazard of building materials is raw material from which they are made. In this respect, they can be divided into three large groups: inorganic, organic and mixed. Let's take a closer look at the properties of each of them. Let's start with mineral materials, which belong to the group of inorganic materials and, along with metal structures, serve to create a rigid frame - the basis of modern buildings.
Most common mineral building materials- this is a natural stone, concrete, brick, ceramics, asbestos cement, glass, etc. They are classified as non-combustible (NG), but even with a small addition of polymeric or organic substances - no more than 5-10% by weight - their properties change. The fire danger increases, and from NG they move into the category of slow-burning.
In recent years, products based on polymers, which belongs to inorganic materials and is combustible. In this case, the affiliation of a particular material to the combustibility group depends on the volume and chemical structure of the polymer. There are two main types of polymer compounds. These are thermoplastics that form a coke layer when heated, which consists of non-combustible substances and protects the material from high temperatures, preventing combustion. Another type is thermoplastics (melted without creating a heat-shielding layer).
Regardless of the type, polymer building materials cannot be classified as non-combustible, but it is possible to reduce their fire hazard. To do this, fire retardants are used - various substances that help to increase fire resistance. Flame retardants for polymeric materials can be divided into three large groups.
The first includes substances that chemical interaction with polymer. These flame retardants are mainly used for thermosets, without deterioration of their physical and chemical properties. The second group of flame retardants - intumescent additives- under the influence of a flame, it forms a foamed cellular coke layer on the surface of the material, which prevents combustion. And finally, the third group is substances that mechanically mixed with polymer. They are used to reduce the flammability of both thermoplastics and thermoplastics and elastomers.
Of all organic materials, wood and its products are most widely used in the construction of modern buildings - particle boards(chipboard), fibreboard(Fibreboard), plywood etc. All organic materials belong to the combustible group, and their fire hazard increases with the addition of various polymers. For example, paints and varnishes not only increase flammability, but also contribute to a faster spread of flame over the surface, increase smoke generation and toxicity. In this case, other toxic substances are added to CO (carbon monoxide), the main combustion product of organic materials.
To reduce the fire hazard of organic building materials, as in the case of polymeric substances, they are treated flame retardants. When applied to a surface, flame retardants can foam or release non-flammable gas when exposed to high temperatures. In both cases, they impede the access of oxygen, preventing the ignition of wood and the spread of flame. Effective flame retardants are substances containing diammonium phosphate, as well as a mixture of sodium phosphate with ammonium sulfate.
Concerning mixed materials, they are composed of organic and inorganic raw materials. As a rule, construction products of this type are not allocated to a separate category, but belong to one of the previous groups, depending on which raw materials prevail. For example, fibrolite, consisting of wood fibers and cement, is considered organic, and bitumen- inorganic. Most often, the mixed type belongs to the group of combustible products.
Increased requirements for fire safety large shopping, entertainment and office centers, as well as high-rise buildings, dictate the need to develop a set of fire prevention measures. One of the most important is the predominant use non-combustible and low combustible building materials. In particular, this applies to the load-bearing and enclosing structures of the building, roofing, as well as materials for finishing escape routes.
According to the classification of NPB 244-97, finishing, facing, roofing, waterproofing and heat-insulating materials, as well as floor coverings are subject to mandatory certification in the field of fire safety. Consider these categories for fire hazard.
Art is a concept for everyone and everyone understands it in their own way. In its first and broadest sense, the term "art" (art) remains close to its Latin equivalent (ars), which can also be translated as "skill" or "craft", as well as to the Indo-European root "composing" or "make up.
Let's start with the main definitions in order to understand in more detail what art is and how much it includes.
Art, as a creative reflection of reality, has emerged and is developing as a system of diverse interconnected species. Types of art - forms of creative activity, differing in the ways of implementation. In turn, various types of art are divided into spatial (plastic), temporal and spatio-temporal (synthetic or spectacular). Plastic arts include fine art - this is a group of arts based on the reproduction of specific phenomena of life in their specific subject appearance.
Painting is a kind of art, the specificity of which lies in the representation of images of reality with the help of paints applied to some surface (base). There are two main types of painting - easel and monumental. Sculpture is one of the oldest types of fine arts, the works of which have a physically material, objective volume and a three-dimensional form placed in real space. Graphics - a type of fine art associated with an image on a plane. There are two main types of graphics - drawing and printed graphics. Decorative and applied art.
Arts and Crafts- (from Latin - to decorate): the art of creating household items designed to satisfy both the practical and artistic and aesthetic needs of people.
Decorative and applied arts - the field of decorative art: the creation of artistic products that have a practical purpose in everyday life and are distinguished by decorative imagery (dishes, furniture, fabrics, clothing, jewelry, toys, etc.). When processing materials (metal, wood, glass, ceramics, textiles, etc.), casting, forging, embossing, engraving, carving, painting, inlay, embroidery, print, etc. are used. The works of DPI are part of the subject environment that surrounds a person, and enrich it aesthetically.
Decorative and applied arts include products made from a variety of materials and using various technologies. The material for the subject of DPI can be metal, wood, clay, stone, bone. The technical and artistic methods of manufacturing products are very diverse: carving, embroidery, painting, chasing, etc. The main characteristic feature of the DPI object is decorativeness, which consists in imagery and the desire to decorate, make it better, more beautiful.
Decorative and applied art has a national character. Since it comes from the customs, habits, beliefs of a certain ethnic group, it is close to the way of life.
An important component of decorative and applied arts is folk art crafts - a form of organizing artistic work based on collective creativity, developing a local cultural tradition and focused on the sale of handicrafts.
The key creative idea of traditional crafts is the assertion of the unity of the natural and human worlds.
The main folk crafts of Russia are:
Woodcarving - Bogorodskaya, Abramtsevo-Kudrinskaya;
Painting on wood - Khokhloma, Gorodetskaya, Polkhov-Maidanskaya, Mezenskaya;
Decoration of products from birch bark - embossing on birch bark, painting;
Artistic processing of stone - processing of hard and soft stone;
Bone carving - Kholmogory, Tobolsk. Khotkovskaya
Artistic processing of metal - Veliky Ustyug black silver, Rostov enamel, Zhostovo painting on metal;
Folk ceramics - Gzhel ceramics, Skopinsky ceramics, Dymkovo toy, Kargopol toy;
Weaving from the vine and cattail
Modern art crafts are developing on the basis of the traditions of arts and crafts. Therefore, in order to understand the nature and essence of such a phenomenon as folk art crafts, it is necessary to understand what folk art is.
Folk art is the creation of products or other objects for practical use with the obligatory decoration of their non-working part.
Folk art is called the art of the masses. The main defining feature of folk art is its collective character. This is primarily manifested in the continuity of centuries-old traditions. For centuries, folk craftsmen have used the secrets of craftsmanship, ornamentation, artistic images, plots transmitted to them by their parents and fellow villagers. Old masters taught young people the art of carving a spoon, painting a spinning wheel, weaving patterned fabrics, sewing clothes, and weaving lace. Traditions of artistic creativity have been preserved from generation to generation. Behind each folk craftsman stands, therefore, the collective experience of many generations of people who are, as it were, co-authors in the manufacture of this or that object.
The collective nature of folk art is also expressed in the close connection of the folk performer with the people around him. The folk craftsman creates things that are necessary, close and understandable to those who live in the same conditions as he does.
Reflecting the collective worldview, works of folk art at the same time necessarily bear the imprint of the master's personality. Without leaving the framework of traditions, the master has a creative attitude to his work: he does not create an exact copy of an already finished product, but at least modifies it in some way. This variation in the master's work is one of the characteristic features of folk art crafts.
Mastery can only be taught by those who themselves master it perfectly. From this point of view, folk crafts are always professional, since a folk craftsman must know the traditional methods of making products and be proficient in them. So, in folk art, the collective and individual principles are in an indissoluble dialectical unity, complementing and enriching each other.
Indeed, folk arts and crafts, recognized today as the direct heir to traditional folk art, have much in common with it. True, from the point of view of its utilitarian and spiritual tasks, traditional folk art was a much broader phenomenon, playing an incomparably greater role in the life of society. On the other hand, its impact was limited to the collective in which it functioned. The cultural significance of modern art crafts has long outgrown the regional scale.
Modern art crafts- these are actually artistic productions, in contrast to the folk art of the past. Their very name, which replaced the previously recognized one - "handicrafts", characterizes their focus on the priority solution of artistic problems. This dominance of the artistic function is to a large extent a consequence of the development of our culture, a response to the problems of the modern object environment. Of course, it does not correspond to the syncretic nature of the traditional culture of the past, reflecting the great changes that have taken place in our society.
At the same time, art crafts are not just one of the components of professional art and the related art industry. They should be seen as folk art productions, in which the main traditions of folk fine arts should be maximally consolidated and organically developed.
« Folk art craft- one of the forms of folk art, the activity of creating artistic products for utilitarian and (or) decorative purposes, carried out on the basis of the collective development and successive development of the traditions of folk art in a certain area in the process of creative manual and (or) mechanized labor of masters of folk art crafts. »
Under product is understood as "... an artistic product of utilitarian and (or) decorative purpose, made in accordance with the traditions of this craft."
We should also not forget about the manufacturers of these products, since in no other industry does the individual work of the master play such a significant role:
« Master folk art craft-- an individual who manufactures products of a certain folk art craft in accordance with its traditions.
In turn, traditions are an established form of making folk art passed down from generation to generation. It takes a certain number of years for a tradition to become established.
This new promising form of production makes it possible to involve ordinary master performers in active creative activity, to make fuller use of their talents and abilities, to combine production replication of products with variation and consistent development of the original sample or ornamental motif, to preserve manifestations of individual performing skills in serial repetition.
Artistry is a special quality of art associated with the impact of an artistic image. Artistry distinguishes art from other types of social consciousness, forms of culture. Imagery is considered to be the most general criterion of artistry. The second, narrower one, is associated with the degree of artistic perfection.
Let us conclude that works of arts and crafts meet several requirements: they have an aesthetic quality; designed for artistic effect; serve for decoration of everyday life and interior. Since the second half of the 19th century, scientific literature has established a classification of branches of decorative and applied art according to material or technique. This classification is due to the important role of the constructive-technological principle in arts and crafts and its direct connection with production.
The concept of "arts and crafts" is quite broad and multifaceted. This is a unique peasant art, rooted in the thickness of centuries; and its modern "followers" - traditional art crafts, connected by a common concept - folk art; and classics - monuments of world decorative art, enjoying universal recognition and retaining the value of a high standard; and modern arts and crafts in a wide range of its manifestations: from small, chamber forms to significant, large-scale ones, from single objects to multi-object ensembles that enter into synthesis with other objects, the architectural and spatial environment, and other types of plastic arts.
Regarding the history of the development of arts and crafts, we can say that it already existed at an early stage in the development of human society and for many centuries was the most important, and for a number of tribes and nationalities, the main area of artistic creativity. The most ancient works of arts and crafts are characterized by exceptional content of images, attention to the aesthetics of the material, to the rational construction of the form, emphasized by the decor. In traditional folk art, this trend has persisted up to the present day.
In the world there is a huge amount of materials that are commonly called "natural". From the name itself, it becomes clear that natural materials include everything that nature itself abundantly presents to us. Throughout the history of development, man has sought to decorate his life, to make the space in which he lives beautiful.
Even primitive man, using the simplest materials, made the first attempts to decorate his home. in an artistic way nature served him. Nature is still a source of inspiration and creation to this day. At any stage of human development, natural elements are an integral part of the decor, they only change under the influence of a particular era.
Modern life takes us away from the use of natural materials, trying to impose the same type of stamped products on us. But who would not like to have a beautiful handmade thing at home or at work, which can be not only a beautiful addition to the interior, but also a useful, functional thing. Public buildings often suffer from a lack of space organization and uniformity of interior design solutions. Great expressiveness and originality are given to the interior by hand-made works, which have their own unique feature and, most importantly, are environmentally friendly.
2.1. Basic concepts. General classification of rocks
The raw materials for obtaining natural stone materials (PCM) are rocks.
Rocks - These are large accumulations of minerals in the earth's crust, formed under the same conditions.
Minerals - these are substances that are products of physicochemical processes occurring in the earth's crust, and have a certain chemical composition, homogeneous structure and characteristic physical properties. Several thousand minerals are known in nature, but only about 50 are involved in the formation of rocks, they are called rock-forming. Rocks can consist of one mineral (monomineral) or several (polymineral).
^ natural stone materials and products are obtained by mechanical processing of rocks, i.e. crushing, splitting, sawing, cutting, grinding (crushed stone, slabs, piece stones, architectural and decorative details) or even without processing (sand, gravel). FROM The properties of the rock from which they are obtained are almost completely preserved.
The building properties of rocks and stone products from them are largely determined by the chemical composition and physical and mechanical properties of rock-forming minerals.
The properties of rocks are also greatly influenced by their structure (structure), which is predetermined by the conditions of formation of each group of rocks. Therefore, in order to assess the properties and determine the appropriate conditions for the processing and use of natural materials in building structures, it is necessary to get acquainted with the composition and structure of the rocks from which they are obtained.
Knowledge of these issues is also important because rocks are also widely used in the building materials industry as raw materials for the manufacture of binders (lime, gypsum, cement), artificial stone materials (ceramic, heat-insulating, concrete, etc.). A wide range of physical and mechanical properties and the prevalence of natural stone materials have led to their widespread use in construction for various purposes. They are used for the construction of foundations and walls of buildings, protective and decorative linings of building structures, floors and stairs, as road surfaces, etc. Hundreds of millions of cubic meters of stone materials in the form of sand, gravel and crushed stone are used annually for the manufacture of concrete, as well as foundations in the construction of railways and roads.
The relatively large variety of rocks used in construction is convenient and logical to study if they are classified according to the conditions of formation (genesis), because this already gives a certain idea of their structure and properties. The genetic classification was developed by Acad. F. Yu. Levinson-Lessing and A. P. Karpinsky and is shown in a schematic form in Table. 2.1.
Table 2.1.
Genetic classification of rocks
| Igneous rocks(primary) | 1. Massive: A) deep: granites, syenites, diorites, gabbro; B) erupted: porphyries, andesites, trachytes, diabases, basalts; |
| 2. Debris: A) loose: volcanic ash, pumice, etc.; B) cemented: volcanic tuffs, trails, tuff lava; |
|
| Sedimentary rocks(secondary) | 1. Mechanical deposits: A) loose: sand, gravel, natural crushed stone; b) cemented: sandstones, conglomerates, breccias |
| 2. Chemical precipitates: some types of limestone, calcareous tuff, magnesite, dolomite, gypsum, anhydrite |
|
| 3. Organogenic deposits: chalk, most limestones, tripoli, diatomites, flasks |
|
| Metamorphic(modified) rocks | Altered Igneous Rocks: Gneisses (from granites) |
| Altered sedimentary rocks: Shales (from clays), marbles (from limestones), quartzites (from sandstones) |
Igneous(primary) rocks formed when magma cooled and solidified.
Sedimentary(secondary) rocks were formed as a result of the natural process of destruction of primary and other rocks under the influence of various and diverse causes acting in nature (mechanical effects, chemical and physical influence external environment).
Metamorphic(modified) rocks were formed as a result of subsequent changes in primary and secondary rocks associated with complex physico-chemical processes that took place in the earth's crust.
The percentage of minerals in the earth's crust up to 16 km deep:
Feldspars and feldspathoids - 60%
Pyroxenes and amphiboles 16%; quartz 12%; mica 4%; other 8%.
The percentage of different genetic groups of minerals in the earth's crust up to 16 km deep (according to Schumann): magmatites - 95%, sedimentary rocks 1%, metamorphites 4%.
^ 2.2. Igneous rocks
2.2.1. Influence of Formation Conditions on the Structure and Properties of Igneous Rocks
Due to differences in the chemical composition of magmas and various conditions and environments in which magma cooled and solidified, igneous rocks of different structure and properties were formed - deep and erupted (dense and porous).
^ Deep rocks formed as a result of honey slow and uniform cooling of magma under a largepressure. Such conditions could arise in nature when the magma cooled down and remained at great depths in the earth's crust. These conditions favored the formation in this rock of minerals with a granular-crystalline structure, firmly intergrown with each other without any cementing substance (granite structure). Characteristic of these rocks is the massive occurrence, high density and, consequently, high compressive strength, low water absorption, significant frost resistance and high thermal conductivity.
| The release of minerals during the solidification of granite magma occurs in a strictly defined sequence. Ore minerals (magnetite, titanite) are formed first, followed by mafic components (pyroxene, hornblende and biotite), then feldspars and later their quartz. The minerals released first have free space for the formation of their own crystalline forms, while the latter are "satisfied" with the remaining gaps between previously formed crystals. That is why quartz in granites is usually devoid of its inherent crystalline form. The main representatives of plutonites are granite, diorite, gabbro, peridotite. Their density in this series increases, while the silica content decreases. Granite and liparite are classified as acidic, diorite as intermediate, gabbro as basic, and peridotite as ultrabasic. The content of dark minerals in this series increases - the color becomes darker. |
^
The outflowing rocks were formed as a result of
less uniform and faster cooling of magmawith a relatively fast and uneven pressure dropion or even at atmospheric pressure. Such conditions could arise when the magma cooled, poured out in the form of lava on the surface of the earth or close to the surface. Under these cooling conditions, large crystalline grains did not have time to form and other genetic structures appeared: cryptocrystalline, glassy (amorphous), porphyritic. The porphyry structure is characterized by a heterogeneous structure, when large crystalline compounds “phenocrysts” are included in the amorphous or finely crystalline mass, which were formed in the magma even in the deep layers during its rise to the earth's surface.
It can be seen from the foregoing that from the same magma, but under different cooling conditions, deep and erupted rocks (called analogues) can be formed, which are close in chemical composition, but differing from each other in structure and properties (see Table 2.). In those cases when the outflowing rocks were formed in a large thickness, their structure and properties are similar to deep rocks. If the formation of erupted rocks occurred in a relatively thin layer and closer to the surface or on the surface of the earth, then they have a heterogeneous, glassy and relatively porous structure.
A variety of erupted rocks are rocks formed during volcanic eruptions. In this case, magma under high pressure in the form of crushed particles was ejected into the atmosphere and, entrained by gases, cooled very quickly and fell to the earth's surface in the form of solidified particles and pieces of various sizes, forming detrital loose rocks of a porous and glassy structure (volcanic ash, sand , pumice). Some of these loose rocks were caked, sintered, or mixed with lava, forming cemented volcanic rocks with a finely porous structure (volcanic tuffs, trails, tuff lava).
^
2.2.2. Chemical and mineral composition of igneous rocks
Most of the igneous rocks used in construction contain chemical compounds of three types - silica, silicates and aluminosilicates in the form of rock-forming minerals (quartz, feldspars, mica and ferruginous-magnesian minerals). Each mineral, in addition to its chemical composition, is characterized by certain and different physical properties (density, hardness, strength, durability, cleavage*, luster, color, etc.). Therefore, the predominance of certain minerals in the rock, their size and location are reflected in the building properties of the stone material.
Quartz - silica(SiO2) in crystalline form. It has a high density - about 2650 kg / m 3, hardness - 7, compressive strength - up to 2000 MPa and durability. During the weathering of igneous rocks, persistent grains of quartz do not collapse and form sands. Quartz has imperfect cleavage, has a different color (colorless, yellow, milky) and glassy luster. At ordinary temperatures, quartz does not interact with acids (except hydrofluoric and hot phosphoric) and alkalis. At elevated temperatures in a saturated steam environment, quartz interacts with alkalis, for example, Ca(OH) 2 , forming hydrosilicates. When heated to 575 and 870 °C, it passes into other crystalline forms, increasing in volume stepwise. Quartz melts at 1710 °C and, upon rapid cooling of the melt, gives quartz glass.
feldspars - aluminosilicates formed as a result of the interaction of silicon and aluminum oxides with oxides of alkali metals. A characteristic feature of feldspars is a pronounced cleavage in two directions. The most common varieties of feldspars are: orthoclase(straight-splitting) K 2 O Al 2 O 3 6SiO 2 and plagioclases(oblique splitting) in the form albite Na 2 O Al 2 O 3 6SiO 2 and anorthite CaO A1 2 O 3 2SiO 2 and mixtures thereof. Feldspars are part of most igneous (up to 2/3 of their mass), many metamorphic and some sedimentary rocks. They have different colors from white and gray to pink and dark red, density 2500...2760 kg/m3, hardness 6, compressive strength up to 170 MPa, melting point 1170...1550 °C. The durability of feldspars is much lower than that of quartz. Under the influence of repeated abrupt changes in temperature and exposure to water and carbon dioxide, feldspars are destroyed (weathered).
micas - minerals with very perfect cleavage in one direction, which are capable of splitting into the thinnest elastic plates. According to the chemical composition, they are aqueous aluminosilicates of complex composition. Most often in the composition of rocks there are two types of mica - muscovite(light aluminum mica) and biotite(iron-magnesian mica of dark color). The density of micas is 2760...3200 kg/m 3 , hardness is 2...3, biotite resistance is less than that of muscovite. When weathered, biotite turns into a hydrated variety of mica - vermiculite. The presence of micas in rocks reduces the strength and durability of the rock, making it difficult to grind and polish.
Ferro-magnesian minerals
for their dark color (from dark green to black) are called dark-colored minerals. According to their chemical composition, they are iron-magnesian silicates. Among the minerals of this group, the most common rock-forming minerals are amphiboles(often hornblende) pyroxenes(for example, augites) and olivines. Minerals of this group are characterized by high density 3000...3600 kg/m 3 , hardness 5.5....7.5, high impact strength, increased weathering resistance (except for olivine). They impart the same properties to the rocks containing them.
^
2.2.3. The most important types of igneous rocks and their building properties
A brief description of the most important types and properties of dense igneous rocks for construction is given in Table. 2.2.
The division of igneous rocks according to their content into acidic, intermediate and basic is of practical importance. So, with a decrease in the content of SiO 2, i.e., as the transition from granites to gabbro or from porphyries to diabases, density, strength, impact strength increase, the melting temperature of these rocks decreases, and the color becomes darker. :
In addition to those listed in Table. 2.2, there are transitional rocks in nature, such as granoporphyry, granosyenite, gabbrodiabase, etc.
Table 2.2.
Characteristics of the most important igneous rocks
| Characteristics for the content of SiO 2,% | breeds | The most important rock-forming materials | Average density, kg/m 3 | |
|
| deep | poured out |
||||
| Sour (65... 76) | Granite | Quartz porphyry, liparite | Quartz, feldspars, mica | 2600…2800 | 100... 250 |
| Medium. | Syenite | Quartz-free porphyry, trachyte | Feldspars, mica | 2600...2800 | 100... 280 |
| Diorite | Andesite, porphyrite | Feldspars, dark colored minerals | 2800... 3000 | 150... 300 |
|
| Main Over 52% | gabbro, labradorite | Diabase, basalt | Dark colored minerals, feldspars | 2900...3300 | 200... 500 |
Granite and related transitional rocks (granitoids) composed of quartz, feldspars, mica, sometimes hornblende or augite. These are the most common of all igneous rocks (up to 2/3 of all deep rocks). The color of the rock is determined by the color of the feldspars (from gray to red in different shades). Having high density and compressive strength (see table. 2.2), granite is brittle, since its tensile strength is 40 ... .60 times less than the compressive strength. Granite has low water absorption - less than 1%, high frost resistance - more than 200 cycles, good abrasion resistance, high thermal conductivity. Granites are well processed (hewn, ground and polished). Fine-grained granites have the highest properties. Granite is used for cladding monumental buildings and hydraulic structures, floor slabs, steps, road materials, coarse aggregate for concrete, rubble, etc.
Syenite unlike granite, it does not contain quartz, but consists mainly of feldspar and dark-colored minerals (up to 15%). In appearance, syenite is similar to granite, but it has a medium-grained structure, and the color is somewhat darker. The properties of syenite are close to those of granite, but it is less resistant to weathering and is easier to process.
Diorite approximately 3/4 consists of feldspars and up to 25% contains dark-colored minerals. Diorite is characterized by a fine- to medium-grained structure and a grey-green or dark green color. In terms of building properties, diorite is not inferior to granites, has high impact strength and is well polished. Most often, diorite is used in facing works and in road construction.
Gabbro consists mainly of feldspar up to 50%) and dark-colored minerals, more often augite, as well as hornblende, olivine. Gabbro is a polycrystalline rock from dark gray to black. Gabbro, consisting of soda-lime plagioclase - labradorite, is called labradorite. A characteristic feature of this breed is irrigation Labrador (blue, light blue, golden colors) on the cleavage planes or the surface of the polished rock. Gabbro is used in the form of piece products for cladding, road surfaces, crushed stone for concrete and other purposes. Labradorite is used for especially valuable facings (for example, it was used in the construction of the Lenin Mausoleum in Moscow).
Porphyry - erupted rocks, similar in chemical composition to granites (quartz porphyry), syenites (quartz-free porphyry), diorites (porphyrite) and characterized by a porphyritic structure. Due to the heterogeneous structure, porphyries are less resistant to weathering and less resistant to abrasion than deep rocks. Other building properties of porphyries are close to those of deep rocks.
Trachyte - an outflowing rock having the same mineral composition as syenites, but more porous, as it hardened on the surface of the earth. It is used as a wall material and crushed stone for concrete. A variety of trachyte - beshtaunit - is used as a filler in acid-resistant concrete.
Andesite - an analogue of diorite, but differs from them in porphyritic structure. Dense andesites are used in the form of acid-resistant slabs and crushed stone for acid-resistant concrete.
Diabase similar in mineral composition to gabbro. Coloring - from dark green to black. The structure is crystalline with grains of different sizes, sometimes porphyritic. Diabases, especially fine-grained ones (for example, Onega), have high strength - up to 450 MPa, high impact strength and low abrasion, capable of splitting into pieces of relatively regular shape. Diabase is used for the manufacture of road materials (setting stones, checkers, side stone), crushed stone for concrete, sometimes for facing works, and also as a raw material for stone casting and acid-resistant products.
Basalt (like diabase, an analogue of gabbro) is a dense, heavy rock that has a hidden crystalline or glassy, and sometimes porphyritic structure. Basalt has a dark gray or almost black color and is characterized by high strength up to 500 MPa. Due to the presence of cracks and pores in the glassy mass, which have arisen during cooling of the magma, or with a porphyritic structure, the strength of basalts can fluctuate sharply, sometimes decreasing to 100 MPa. The high hardness and brittleness of basalts makes them difficult to process. They are widely used as a road material, as crushed stone for concrete, for acid-resistant materials, as well as stone casting and mineral wool production.
Powdered particles (up to 1 mm) are called volcanic ash, size up to 5 mm - volcanic sands, and from 5 to 30 mm (rarely larger)- pumice. These rocks have a porous structure, low density and low thermal conductivity - 0.13 ... 0.23 W / (m ° C), compressive strength - 2 ... 3 MPa.
Pumice and pumice sands are used as a filler in lightweight concrete, in the production of heat and sound insulating materials, and as a grinding material. Since these rocks consist of amorphous silica and volcanic glass, they are used in finely divided form as active additives to mineral binders.
Volcanic tuffs formed as a result of subsequent compaction, sintering or cementation with natural cements of volcanic ash. The most compacted volcanic tuffs are trails. If, during an eruption, a significant amount of volcanic ash and sand is mixed with liquid lava, then rocks called tuff lava are formed. Most volcanic tuffs and tuff lavas have a porous structure, low density, and low thermal conductivity. These rocks have a variety of colors and are easy to process.
One of their typical representatives is the Artik tuff mined in Armenia. Artik tuff has a pinkish-violet color, density 750...1400 kg/m3, compressive strength 6...10 MPa, thermal conductivity about 0.34 W/(m°C); sufficient frost resistance.
Tufas are used for laying walls in the form of sawn stones of the correct shape and rubble, and in crushed form - as aggregates for lightweight concrete.
^
2.3. Sedimentary rocks
2.3.1. Classification of sedimentary rocks
In the composition of the lithosphere, sedimentary rocks account for only about 1%, but they occupy up to 75% of the Earth's surface area. Sedimentary rocks are characterized by layering (they are called bedded) and in most cases a more porous structure and lower strength than dense igneous rocks. Depending on the conditions of formation, sedimentary rocks are divided into three groups: mechanical deposits (detrital), chemical sediments, organogenic deposits.
Mechanical deposits (loose and cemented) were formed as a result of the destruction of other rocks under the influence of the weathering process (the action of water, wind, temperature fluctuations, freezing and thawing, and other atmospheric factors). As a result, even the strongest massive igneous rocks are destroyed, forming fragments of various sizes: blocks, pieces and smaller particles.
Along with mechanical destruction as a result of the interaction of the constituent parts of rocks with substances in the environment, chemical destruction can occur. So, feldspars under the action of water containing carbon dioxide are destroyed, forming aqueous aluminum silicates, in particular the mineral kaolinite - A1 2 O 3 2SiO 2 2H 2 O, hydrous silica and carbonate salts of potassium, sodium, calcium:
K 2 O Al 2 O 3 6SiO 2 n H 2 O CO 2 \u003d K 2 CO 3 A1 2 O 3 2SiO 2 2H 2 O 4SiO 2 mH 2 O
Destruction products remain in place or are more often transferred by water flows, wind, glaciers to other places and, after settling, form loose accumulations of clastic sedimentary rocks (sand, clay, gravel, natural rubble). Some of them are subsequently cemented with natural cements that precipitated in the thickness of loose sediments from the solutions washing them, forming solid (cemented) rocks of various densities (sandstones, conglomerates, breccias).
Chemical precipitation formed as a result of precipitation of substances that passed into the composition of aqueous solutions in the process of destruction of rocks. They are the result of changing environmental conditions, the interaction of solutions of different composition and evaporation (gypsum, anhydrite, magnesite, dolomite, calcareous tuffs).
Organogenic deposits
- rocks formed as a result of the deposition of dying flora and small animal organisms of water basins.
Many marine organisms during their lifetime extract calcium salts, dissolved silica from the water to build their skeletons, shells, shells, and stems. After dying off, settling to the bottom and compacting, they form bedded deposits of organogenic rocks. Chalk, various types of limestone, diatomites and tripoli are used for construction purposes.
^
2.3.2. Chemical and mineral composition of sedimentary rocks
The average bulk chemical composition of all sedimentary rocks is close to the composition of igneous rocks, but individual sedimentary rocks differ much more from each other than igneous ones. Sedimentary rocks used for construction purposes most often contain the following chemical compounds: silica in crystalline and amorphous states (anhydrous and aqueous), aluminosilicates (mainly aqueous), carbonates (anhydrous), sulfates (anhydrous and aqueous). These compounds are the main minerals of sedimentary rocks used in construction: quartz, opal, kaolinite, calcite, magnesite, dolomite, gypsum, anhydrite.
Quartz(crystalline silica), due to its high resistance to weathering, remains chemically unchanged and is part of many sedimentary rocks (sands, sandstones, clays, etc.). In the amorphous state, silica occurs in sedimentary rocks in the form of the mineral opal.
Opal(SiO 2 nH 2 O) is less dense (p o \u003d 1900 ... 2500 kg / m 3), durable and resistant than quartz. It is characterized by increased internal microporosity and fine structure, has a high reactivity to calcium hydroxide and other basic oxides. This property of amorphous silica is widely used in the manufacture of mineral mixed binders.
Kaolinite(Al 2 O 3 2SiO 2 2H 2 O) - hydrous aluminum silicate, formed during the weathering of feldspars and micas. The color of kaolinite without impurities is white, density is 2600 kg/m 3 , hardness is 1. Kaolinite and other aqueous aluminosilicates of the Al 2 O 3 nSiO 2 mH 2 O type are the main ones in the formation of clays. They are often found as impurities in limestones, sandstones, gypsum and other sedimentary rocks. The presence of these impurities reduces the water and frost resistance of rocks.
Calcite(CaCO 3) has perfect cleavage in three directions, density 2700 kg / m 3, hardness 3. Calcite dissolves in acids, in ordinary water - a little (about 0.03 g / l). This is a common mineral that makes up various types of limestone. The color is white, gray, sometimes it is transparent.
magnesite(MgCO 3) has a density of 2900 ... 3100 kg / m 3, hardness 3.5 ... .4, 5. It is much less common than calcite and forms a rock of the same name.
Dolomite(СаСО 3 MgCO 3) is similar in physical properties to calcite, but is harder - 3.5.. .4, dense (p o = 2900 kg / m 3) and durable. The color of dolomite is from white to dark gray, depending on impurities. It occurs more frequently than magnesite, forming the rock of the same name or being incorporated into limestones and other sedimentary rocks.
Gypsum(CaSO 4 2H 2 O) - a mineral of a crystalline structure, its crystals have a granular, columnar, lamellar, acicular or fibrous structure. It is white, sometimes stained with impurities. It has cleavage in one direction. The density of gypsum is 2300 kg/m 3 , hardness is 2, it dissolves relatively easily in water. Gypsum forms the rock of the same name.
Anhydrite(CaSO 4) - an anhydrous variety of gypsum, forms rocks of the same name. Density of anhydrite is 2900…3000 kg/m 3 , hardness is 3...3.5.
^
2.3.3. The most important types of sedimentary rocks and their building properties
Many sedimentary rocks are used as raw materials for other building materials, and some for direct use as building stone.
^ Sand and gravel- rocks formed as a result of weathering of various rocks. The grain size of sand is 0.16 ... 5 mm, gravel - 5 ... 70 mm or more.
Clay are fine clastic deposits formed as a result of weathering of feldspar rocks (granites, gneisses, etc.). In terms of composition, clays are a mixture of minerals of the kaolinite group with quartz grains, mica, iron oxides, calcium and magnesium carbonates. Kaolinite clays (kaolin) are white in color, other clays, depending on the type and amount of impurities, may have a different color, up to black. Clay, when moistened, acquires plastic properties and, after firing, passes into a stone-like state. It is the main raw material in the ceramic industry and in the production of cements.
^ Gypsum and anhydrite- rocks of chemical origin, consisting mainly of the mineral gypsum and anhydrite. Outwardly and in their physical and mechanical properties, they differ little from each other. They are used for the production of binders, and some varieties - for the interior cladding of buildings.
magnesite- a rock of chemical origin, consisting mainly of the mineral magnesite. It is used for the manufacture of refractory products, partly for the production of binders (caustic magnesite).
Chalk- a rock of organogenic origin, usually white, earthy build, represented by microscopic shells of the simplest organisms. In terms of chemical composition, it almost entirely consists of calcium carbonate, and has low strength. It is used as a white pigment in paint compositions, in the preparation of putty, as well as in the production of lime and Portland cement.
diatomaceous earth- an organogenic rock formed from the shells of diatoms and partly from the skeletons of radiolarians and sponges, between which the finest silt and clay were deposited. Composed primarily of amorphous silica in the form of the mineral opal.
Tripoli- a rock that formed before diatomite, and unlike it, it consists of amorphous silica in the form of tiny opal balls cemented with opal cement. Diatomaceous earth and tripoli are similar in properties. Their porosity is 60...70%, density is 350...850 kg/m 3 , thermal conductivity is 0.17...0.23 W/(m °C). The content of active silica is 75...96%. Tripoli and diatomaceous earth are used for the manufacture of heat-insulating materials, as active mineral additives to binders. Over time, the tripoli turns into a finely porous or dense, hard-to-soak rock - flask, composed almost entirely of amorphous silica.
As a building stone, limestones of various types, dolomites and sandstones are mainly used. The composition and some properties of these rocks are given in Table. 2.3.
Table 2.3.
Composition and properties of some sedimentary rocks
| Breed | Basic minerals | Density, kg / m 3 | Compressive strength, MPa |
|
| true | average |
|||
| Limestone is dense | Calcite, dolomite | 2600...2800 | 1800.. 2600 | 15...100 (sometimes up to 180) |
| Limestone porous: | 2600…2800 | 900… 1400 | 0,4. ..15 |
|
| Shell rock, Calcareous tuff | Same Calcite | 2800...2800 | 1600…1800 | 5...15 (some up to 80) |
| Dolomite | Dolomite | 2500...2900 | 2200...2800 | 15...200 |
| Sandstone: siliceous | 2500...2900 | 2300...2600 | 30... 200 And more |
|
| Quartz, |
||||
| opal |
||||
| lime | Quartz, | |||
| calcite |
||||
Limestones in in most cases, they are organogenic rocks, but there are limestones of chemical origin (calcareous tuffs). Limestones are mainly composed of the mineral calcite, but often contain various impurities (silica, clay, dolomite, iron oxides, organic compounds), depending on which the color of limestones can be from white to dark gray with various shades.
The admixture of clay in limestone used as a building stone, even in a small amount (3 ... 4%), sharply reduces their water and frost resistance. Pyrite also has a harmful effect on the building properties of limestones. FeS 2 . Limestones containing some silica are stronger and more resistant than other types of limestones. Limestones containing dolomite are called dolomitic.
^ dense limestones (density more than 1800 kg / m 3), consisting of small grains of calcite, connected by direct adhesion of crystals or various natural cements (lime, calcareous-siliceous), are used in the form of rubble stone (for foundations, walls of unheated buildings or residential buildings in areas with a warm climate ), slabs and fittings for wall cladding, plinths and cornices, steps, as well as crushed stone for concrete, road bases and raw materials for lime and Portland cement.
Limestone-shell rocks- porous rocks are characterized by low density, low strength and low thermal conductivity (see Table 2.3). They are used in the form of stones of the correct form for laying walls, and the most dense varieties - for wall cladding, as well as crushed stone for lightweight concrete.
^ calcareous tuffs - porous limestones of chemical origin. Despite significant porosity, calcareous tuffs are characterized by sufficient frost resistance, since due to their cellular structure (closed or large pores) they have relatively low water absorption. A variety of calcareous tuff - travertine, which has a fine-grained structure and high compressive strength (up to 80 MPa), is used for cladding buildings.
Dolomite- a rock of chemical origin, consisting of the mineral dolomite. Its properties are close to dense limestone. Dolomite is used for the same purposes as limestone, as well as for the production of refractories and heat-insulating materials.
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Sandstones, conglomerates and breccias
- rocks formed from loose deposits of collapsed rocks as a result of their cementation with various natural cements (calcareous, siliceous, clayey, ferruginous, etc.). As a result of cementation of sands, sandstones are formed, grains of gravel - conglomerates, natural crushed stone - breccias. The most durable and resistant calcareous and siliceous sandstones, as well as conglomerates and breccias based on these natural cements, are used as building stone. Most sandstones are dense, heavy, and thermally conductive materials. They are mainly used for laying foundations, walls of unheated buildings, steps, sidewalks, building cladding, as well as in the form of crushed stone for concrete and other purposes. Decorative conglomerates and breccias are used as facing stone.
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2.4. The most important metamorphic rocks
Metamorphic (modified) rocks are formed in nature as a result of changes in the composition and structure of sedimentary and igneous rocks. Metamorphic processes take place at elevated temperatures without melting or dissolution, under the influence of high pressures and shear deformations. Such conditions arise when the original rocks as a result of mountain building processes can move from the surface into the depths of the earth's crust. As a result, recrystallization of minerals can occur, the structure can change profoundly, i.e., completely new rocks can be formed, denser and in most cases with a clearly defined crystalline structure. These rocks can be completely modified (for example, marble) or with a noticeable content of the original rock (marble limestones).
The mineral composition of metamorphic rocks is often identical to the original igneous or sedimentary rocks.
The texture of metamorphic rocks can be shale (gneisses, clay shales) and massive (marble and quartzites). ^ slate structure characteristic of modified rocks formed under conditions of unilateral pressure. Schistosity reduces the structural properties of metamorphic rocks, in particular, frost resistance and strength in the direction parallel to schistosity, but gives them the ability to split relatively easily along the schistosity planes into more or less thin layers.
^ Massive grainy texture characteristic of rocks formed under multilateral pressure, when the original sedimentary rock, as a result of recrystallization and compaction, becomes monolithic, consisting of closely intergrown crystalline grains. Such rocks are characterized by a very high density compared to the sedimentary rocks from which they were formed.
In the construction of metamorphic rocks, gneisses, clay shales, marbles, and quartzites are used.
gneisses in terms of mineral composition and properties, they are similar to the rocks of the granite type from which they were formed. Due to the slate structure, they are less durable. In construction, they are most often used in the form of rubble slabs for laying foundations, sidewalks, embankments, and canals.
Shale - typical shale metamorphic rocks formed from clays; color black or dark grey. Clay slates do not soak in water, are resistant to weathering, easily split into thin even tiles (3 ... 10 mm), used as roofing material (natural slate).
marbles formed as a result of the modification of limestones (rarely dolomites) and consist of firmly intergrown calcite crystals, sometimes with impurities of dolomite grains, manganese, iron and carbon compounds, giving them a different color. With an uneven distribution of impurities, marbles have a variegated color with various patterns that give the stone a decorative effect. Marbles are distinguished by high density - up to 2900 kg / m 3, low water absorption - up to 0.7%, high compressive strength - up to 300 MPa, but have low hardness - 3. Marble is well ground and polished, sawn into thin slabs. It is widely used for interior wall cladding, the manufacture of steps, window sills and other products. Varieties of marble that are unsuitable for piece products, or waste in the processing of marble in the form of crumbs, are used as fillers for finishing mortars and concretes. Most marbles are not recommended for exterior cladding of buildings, because under the influence of atmospheric agents (water, sulfur dioxide, temperature changes, etc.), the marble surface loses its decorative appearance and undergoes noticeable corrosion (it becomes dull, rough and more porous).
Quartzites
formed as a result of the modification of siliceous sandstones. They have a dense structure and consist of recrystallized quartz grains cemented with quartz cement. Coloring - white, red, dark cherry. Quartzites have a high density - about 2700 kg / m 3, low water absorption - less than 0.2%, significant compressive strength - up to 400 MPa, high hardness - 7 and durability. Quartzites are used for external cladding of increased durability, under-truss stones in bridges, sometimes in the form of crushed stone and rubble, and also as a raw material for the manufacture of Dinas refractories.
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2.5. Materials and products made of natural stone
Types of materials and products. Technical requirements for them
Stone materials are divided according to density: heavy - with a density of more than 1800 kg / m 3 and light - less than 1800 kg / m 3; on compressive strength(MPa) - for grades: for heavy - from 10 to 100, for light - from 0.4 to 20; on frost resistance - for grades: F 15...500 (heavy) and F 10...25 (light); on water resistance- for groups with a softening coefficient of at least 0.6; 0.75; 0.9 and 1.
Depending on the purpose and conditions of use, natural stone materials are also evaluated according to hardness, abrasion and impact resistance loads (e.g. road materials), resistance against various chemical influences external environment, etc.
By degree of processing stone materials are distinguished: rough (rubble stone, crushed stone, gravel, sand) and profiled (sawn piece stones and blocks for walls; stones, slabs and profile products for exterior and interior cladding of buildings and structures, floors; road construction, etc.).
rubble stone (but) - pieces of stone 150 ... 500 mm in size according to the largest dimension. Torn boot ( irregular shape) is mined mainly by blasting, and limestone (bedded) is obtained from rocks of reservoir occurrence by splitting with a stone-split tool. Dams, retaining walls, foundations and walls of unheated buildings are built from rubble. Due to the irregular shape of the stones, rubble masonry is laborious and requires an increased consumption of mortar. In industrial construction, it is replaced by prefabricated concrete and reinforced concrete elements. In this regard, a significant part of the mined buta is processed into crushed stone or used in rubble concrete (concrete with the inclusion of rubble stone in its composition).
rubble - pieces of stone with a size of 5 ... 70 mm (for hydraulic engineering construction up to 150 mm). It is obtained by crushing from durable and frost-resistant rocks. There is also natural crushed stone, called gruss.
Wall stones and blocks are made from porous limestones, volcanic tuffs and other rocks with a density of up to 2100 kg / m 3 and a compressive strength of 2.5 ... 40 MPa. The correct geometric shape of stones and blocks is obtained, as a rule, by sawing them out of an array using stone-cutting machines; chipped piece stones are produced much less frequently. The dimensions of stones and blocks must be a multiple of the installed single building module of 100 mm. Taking into account the thickness of the joints, stones and blocks are 38 ... 302 cm high, 82 ... 100 cm wide, 30 ... 50 cm thick. Enlargement of stones makes it possible to reduce labor costs during masonry and increase the industrialization of construction. The cost of 1 m 3 of natural wall stone is on average 2 times lower than the cost of 1 m 3 of ceramic bricks, and the specific capital investments for organizing the extraction of sawn stone are 2 ... 2.5 times less than bricks. It is especially effective to use natural wall stones where they are local materials (in the Crimea, Moldova, Transcaucasia, etc.).
Cladding boards, stones and profile products are made by sawing or splitting blocks of rocks with their subsequent mechanical processing to give the correct shape, size and obtain a certain texture of the front surface.
Boards for exterior cladding buildings, embankments, bridge supports, hydraulic structures, for durable and decorative floors of public buildings with intense human flows are made from dense rocks, in which cracks and the content of clay and other impurities are not allowed.
For interior cladding Marbles and marble-like limestones, anhydrite and other soft, well sawn rocks are used.
The thickness of chipped and hewn slabs for wall cladding is 100 ... 250 mm, sawn slabs - 12 ... 80 mm. Sawing rocks with diamond tools makes it possible to produce slabs with a thickness of less than 10 mm. The cost of 1 m 2 of such plates is 2...4 times lower than the usual ones. Sawn slabs are more weather resistant than hewn slabs, since impacts during hewing crush crystals, creating microcracks. From the same rocks, profile parts are also made (basement slabs and stones, port parts, plinths, belts, cornices, window sills and corner slabs), as well as elements of stairs and platforms. The high durability of natural stone facings reduces the labor costs for their operation by 5...8 times compared to buildings finished with colored mortars and concretes or painted with silicate and lime paints.
Materials and products for road construction are made from igneous and sedimentary rocks, which have high strength, low water absorption, good resistance to shock and abrasion, frost-resistant and unaffected by weathering.
side stones they are made by chipping and trimming rocks, and the upper part of the side stone, protruding above the road surface, is hewn cleanly, and the lower part is roughly. The cost of such stones is higher than concrete side ones, but they are much more durable. These stones may be used instead of concrete only with an appropriate feasibility study.
^ Paving stones and checker they are made by machine (by splitting) mainly from diabase and granite and are used in the construction of pavements, etc.
Heat-resistant and chemically resistant materials and products
used in the form of regular-shaped stones and shaped plates (smooth and corrugated), crushed stone and sand for concrete and mortar, as well as finely ground powders for mastics, putties, putties, etc. For materials and products operating at high temperatures, basalt, diabase, andesite, tuff, chromite are used. Products made of granite, syenite, diorite, basalt, siliceous sandstone, and quartzite are used to protect the structures of buildings and apparatuses from acids (except for hydrofluoric and hydrofluorosilicic acids). Slabs and stones made of dense limestones, dolomites, marbles, magnesites and calcareous sandstones are well maintained in an alkaline environment. An important condition for the service of stone materials in aggressive environments is their high density. For operation in such conditions, they must have a density and compressive strength, respectively, not less than 2300 kg / m 3 and 30 MPa for sedimentary rocks and not less than 2400 kg / m 3 and 100 MPa for igneous, softening coefficient 0.8 ... 0.9, acid resistance not less than 93...95%.
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2.6. Mining and processing of stone materials
The technology of stone materials and products includes the extraction of rock and its processing.
Loose rocks (sand, gravel, clay) are mined in an open way, using single and multi-bucket excavators or with the help of hydromechanization. In the latter case, water supplied by a high-pressure jet monitor erodes the rock and then from an easily flowing mixture of water and rock (pulp) - in specially designated places, sand or gravel is deposited and sorted.
Dense rocks , used to obtain torn rubble, crushed stone or raw materials for other building materials, are usually developed in an explosive way.
porous rocks (shell limestone, tuff) used for piece wall stones and blocks are usually developed by special stone-cutting machines, the main cutting elements of which are circular saws with cutters on the rim reinforced with hard alloys or diamonds. To obtain larger blocks, machines with endless cutting chains or machines in which the discs are replaced by annular cutters are used.
The development and processing of rocks intended for cladding include the following operations: separation of large-sized semi-finished blocks (4 ... 50 m 3) from the array; sawing or splitting blocks into slabs or other forms of products; processing of edges and surface of products.
When extracting blocks, drilling, abrasive and thermal methods are used. Buroklinovoy method is used in the extraction of very hard and durable rocks (granite and other igneous rocks). The abrasive method (sawing) is used when cutting blocks from softer rocks (marble, limestone, tuff). In the thermal method, a high-temperature (over 2500 ° C) gas jet is directed to the developed rock. This jet is ejected from the combustion chamber of kerosene in oxygen or gasoline in air at supersonic speed (about 2000 m/s) and destroys the rock.
Blocks are cut into slabs more often with frame saws, less often with cable saws. In both cases, abrasive powder (quartz sand, hardened steel powder, etc.) is used, which is supplied together with water under saw blades (ropes), which actually performs sawing, or saws reinforced with carbide or diamond inserts are used.
Milling and profiling machines are used to cut slabs and obtain profiled products (belts, cornices, etc.). The cutting element in these machines are abrasive discs or profiled parts made of extra hard abrasives. The surfaces of slabs and other stone materials are given one or another texture (surface relief). To do this, impact processing of hard rocks (chipping off their surface with blows) with various stone cutting tools or abrasive processing (sawing, grinding, polishing) is used, as well as heat treatment. A description of the types of invoices is given in Table. 2.4.
Table 2.4 .
Types of textures of stone materials
| Processing method | Texture | Brief description of the invoice |
| Shock (beating with blows) | Rock | View as when splitting the rock (large mounds and depressions) without traces of the tool on the surface |
| corrugated | Correct alternation of ridges and troughs up to 2 mm deep Uniformly rough with intermittent grooves 0.5 ... 1 mm deep |
|
| furrowed (forged) |
||
| dotted | Uniformly rough with punctate depressions 0.5. ..2 mm. |
|
| Abrasive (treatment with abrasive materials) | sawn | Uneven distribution of grooves up to 2 mm deep |
| sanded | Uniform roughness with relief depth up to 0.5 mm |
|
| polished | Smooth velvety-matte with a revealed pattern and color of the stone |
|
| Mirror | Mirror-shiny with fully developed color and stone pattern |
Polished, polished and mirror textures are obtained on special grinding and polishing machines. The use of fine and dusty diamonds as an abrasive material in grinding and polishing, as well as in cutting, dramatically increases the productivity of machine tools, improves the quality of products and reduces their cost.
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2.7. Measures to protect stone materials from weathering in structures
An indispensable condition for the long service life of stone materials in structures is their correct choice, taking into account the operating environment, chemical and mineralogical composition and structure of the material. However, even the most durable rocks from which the material is made are destroyed under the continuous mechanical and chemical influence of atmospheric factors and various microorganisms. This process, by analogy with the destruction of rocks on the earth's surface, is called weathering.
The main reasons for the weathering of natural stone materials in structures are: freezing of water in pores and cracks, causing internal stress; frequent changes in temperature and humidity, causing the appearance of microcracks; dissolving action of water and lowering of strength at water saturation; chemical corrosion due to gases (O 2 , CO 2, etc.), contained in the atmosphere, and substances dissolved in ground or sea water. Various microorganisms and plants (mosses, lichens), settling in the pores and cracks of the stone, extract alkaline salts for their nutrition and release organic acids that cause the biological destruction of the stone.
The resistance of materials against weathering is the higher, the lower their porosity and solubility. Therefore, all measures to protect stone materials from weathering are aimed at protecting them from the effects of water and increasing their surface density. These measures can be constructive and chemical.
Structurally, the protection of structures from moisture is carried out by arranging proper water drains, giving stone materials a smooth surface and such a shape that water falling on them does not linger and does not penetrate into the material.
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Chemical measures include the creation of a dense waterproof layer on the front surface of the stone or its hydrophobization.
One way to increase the surface density is fluatation, in which carbonate rocks are impregnated with salts of fluorosilicic acid, such as magnesium fluate. As a result of the reaction taking place:
2CaCO 3 MgSiF 6 \u003d 2CaF 2 MgF 2 SiO 2 2CO 2.
in the surface pores of the stone, almost water-insoluble calcium and magnesium fluorides and silica are released, reducing the porosity and water absorption of the surface layer and somewhat preventing contamination of the lining with dust. Non-carbonate porous rocks are pretreated with aqueous solutions of calcium salts, for example, calcium chloride, and after drying, with soda, then with fluate.
Hydrophobization, i.e., the impregnation of porous stone material with hydrophobic (water-repellent) compounds that prevent the penetration of moisture into the material also increases their resistance to weathering.
Good results are obtained by impregnation with organosilicon liquids and other polymeric materials, as well as solutions of paraffin, stearin or metal soaps (aluminum, zinc, etc.) in volatile organic solvents (gasoline, varnish kerosene, etc.).
The durability of a porous stone is significantly increased by the impregnation of its surface layer with a monomer solution, followed by polymerization of the monomer in the pores of the stone during thermal catalytic or radiation treatment.
Literature
Domokeev A.G. Construction Materials. - M. Higher. school , 1987. - 495 p.
V. Schumann. The world of stone. Volume 1. - M. Mir, 1986. - 216 p.
Walter Schumann. Stein Mineralien. Mineralien, Edelsteine, Gesteine, Erze. – München, Bern, Wein: BLV Verlagsgeselschaft – 460 s.