What is the difference between black crushed stone and asphalt concrete mixture?

Black rubble. Photos of Soil Trucks

Fractional materials are widely used in various fields of activity , in particular in construction. They act as a filler in the production of concrete, are used when performing facing work, and are used for arranging cushions for foundations, road surfaces, drainage, etc. Crushed stone is a popular material for construction projects.

Companies and private clients are provided with several types of crushed stone in accordance with their origin, the greatest interest is gravel, granite, limestone, dolomite, marble, expanded clay, basalt, quartz and slate, secondary, slag and others. All of them are natural materials produced by crushing rock and sifting the resulting fragments into separate fractions. Black crushed stone, which will be discussed in this article, in turn is a partially artificial bulk material.

Making black crushed stone with your own hands

For these purposes, limestone stone M-600 with a maximum fraction of 20 mm is best suited, since its ability to absorb emulsion is higher than that of other types. In addition, you will need petroleum bitumen grade BND 200/300 in an amount of 4.5÷5% by weight of crushed stone. VAT residues of synthetic fatty acids should be used as a surfactant - about 3% by weight of bitumen. To create an effective emulsion, you need an aqueous solution of NaOH - only about 0.4% by weight of water.

TU 400-24-163-89*Black hot crushed stone

TU 400—24—163—89 *

CRUSHED BLACK HOT

Moscow, 1995

PREFACE

1. DEVELOPED AND INTRODUCED by the Scientific Research Institute of Moscow Construction (NIIMos-Stroy) of the Construction Department.

Developers: V. N. Kononov, Doctor of Technical Sciences, development manager, M. I. Kleiman, p. n. With.

2. ACCEPTED AND ENTERED INTO EFFECT 02/03/1989 Registration of MCSM Gosstandart 005/018180 dated 02/02/89.

3. INTRODUCED to replace TU 400-24-103—76.

4. REPUBLISHED (02/16/95) with CHANGE No. 1 Goskomstandart. Registered and entered into the register on 03/02/95 under GR No. 200/018180/01 without an expiration date.

5. This document implements the norms of the Law of the Russian Federation “On Standardization”.

Black hot crushed stone

Date of introduction 1989—02—03

These technical specifications apply to black hot crushed stone used to create a rough surface of an asphalt concrete pavement using the embedding method during the construction and repair of road pavements.

Black crushed stone is prepared by mixing in mixing plants in a heated state one-dimensional crushed stone with viscous petroleum road bitumen, taken in certain proportions. If there is insufficient adhesion of bitumen to the surface of crushed stone, additives of surfactants and surface activators (lime, mineral powder, cement) are introduced.

An example of recording a product designation when ordering it: “Black crushed stone, fractions 5-10”, TU 400-24 - 163-89*

I. TECHNICAL REQUIREMENTS

Black hot crushed stone (hereinafter referred to as black crushed stone) must comply with the requirements of these technical conditions and be manufactured in accordance with technical regulations approved in the prescribed manner.

1.1. Basic parameters and dimensions.

1.1.1. The main parameters and dimensions must correspond to the values ​​​​indicated in the table.

Table

Codes and main classification features of the material

1.1.2. The heating temperature of crushed stone should be no more than 160°C, and bitumen ^ 150°C. When using surfactant additives, the maximum temperature of materials is reduced by 15°C.

1.1.3. Crushed stone surface activators are introduced into the mixer before feeding bitumen: fluff lime - from 1 to 2% (or milk of lime: 30% dry matter and 70% water) or mineral powder - from 0.5 to 4%, or cement - from 3 to 4% by weight of crushed stone.

1.1.4. All components are dosed by weight. The permissible error should not exceed +2%.

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1.1.5. The duration of mixing crushed stone with viscous petroleum bitumen in mixers with a circulation circuit for the movement of material is 20-40 s. A shorter time is set for mixtures in which bitumen is introduced into the mixer in sprayed form under pressure. In mixers with a countercurrent flow pattern for materials, the mixing time should be increased by 1.5-2 times.

1.1.6. The temperature of black crushed stone when discharged from the mixer should be in the range of 120-140°C.

Minimum temperatures should be adhered to when using crushed stone from igneous rocks and performing work at outdoor temperatures above 25°C; maximum - the same at a temperature of 10-25 ° C and the use of crushed stone from artificial stone materials.

1.2. Characteristics (properties).

1.2.1. To prepare black crushed stone, crushed stone is used, obtained by crushing natural or artificial stone that meets the requirements of GOST 8267-82, GOST 10260-82, GOST 8268-82, TU 21-0284461 - 1-85.

For the production of crushed stone, the most preferable are igneous rocks (crystalline, without traces of weathering) - granites, syenites, diorites and artificial ones - dorsil.

According to the shape of the grains, crushed stone should be cuboidal in shape with pronounced edges, uniform in strength, clean and of the same type in color. The grain content of soft rocks should not exceed 5% by weight.

In terms of strength, crushed stone must have a grade of at least 1000 for crushability when compressed (crushed) in a cylinder, for wear in a shelf drum of I-G1, and a frost resistance rating of at least F 50.

1.2.2. To prepare black crushed stone, petroleum viscous road bitumen is used that meets the requirements of GOST 22245-90.

1.2.3. The mineral powder used to activate crushed stone must meet the requirements of GOST 16557—78, and the lime must be grade 1, 2 or 3 and meet the requirements of GOST 9179-77*

Cationic-type additives are used as surfactants in accordance with technical requirements VSN-59-68.

5

1.2.4. The produced black crushed stone must be homogeneous and one-dimensional and have a uniformly distributed film of bitumen on the surface, ensuring proper adhesion of the crushed stones during compaction.

2. CONTROL (TEST) METHODS

2.1. Quality control of finished black crushed stone is carried out according to external characteristics, taking into account the following main factors: the degree of homogeneity and one-dimensionality of the crushed stone used and the coating of the crushed stone surface with bitumen. Bitumen should not drain from the treated crushed stones, but at the same time it should completely and evenly envelop them, forming a durable film.

2.2. The temperature regime for preparing black crushed stone is controlled by checking the temperatures of the mineral and binder material and the finished black crushed stone. The temperature of the finished black crushed stone is checked in the back of vehicles.

2.3. Methods for monitoring the source materials used for the preparation of black crushed stone, if necessary, to check their quality must comply with:

GOST 11001 -78 - GOST 11512-78* - for bitumen;

GOST 8269-87 - for crushed stone;

GOST U179—77?—for lime;

GOST 12784-78 - for mineral powder;

VSN 59-—68 Ministry of Transport - for surface-active additives;

GOST 8267-82 - for crushed stone.

3. ACCEPTANCE RULES

3.1. The finished black crushed stone is accepted by the technical control department of the manufacturer.

3.2. Acceptance of black crushed stone is carried out in batches. The batch size is established in the amount of shift output of one mixing plant, one composition, made from the same materials, and using the same technology.

3.3. To check the quality of black crushed stone and compliance with the requirements of these technical specifications at the time of its

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samples are taken from the mixer into vehicles. Each sample is made up of separate portions of black crushed stone, selected from 3-4 batches.

3.4. The consumer has the right to carry out a control check of the quality of black crushed stone, applying for this purpose the selection and rejection rules in accordance with GOST 12801 - -84 and the methods for assessing the material provided for by these technical conditions.

3.5. Marking.

When shipping to the consumer, the manufacturer is obliged to accompany each transport unit delivering black crushed stone to the place of work with a consignment note (passport), which must indicate:

name of the manufacturer; temperature of black crushed stone; number, date and time of issue of the invoice; name and address of the consumer; designation of these technical conditions.

4.1. Black crushed stone is delivered from the plant to the work site in dump trucks and unloaded into the receiving hopper of a stacking or distribution mechanism. Dump trucks delivering ready-made crushed stone must have normal pressure in the spikes, and the bodies must be in good working order, clean and without any residue of mixture adhering to the walls and bottom of the body.

4.2. Ready-made black crushed stone cannot be stored and is placed in the coating immediately after it is delivered to the work site.

Black crushed stone must be accepted by the technical control of the manufacturer.

5.2. The supplier (manufacturer) guarantees the compliance of black crushed stone with the requirements of these technical specifications, provided that the consumer complies with the conditions of use and transportation established by the technical specifications.

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6. SAFETY AND OCCUPATIONAL HEALTH REQUIREMENTS

6.1. To prepare black crushed stone, viscous petroleum bitumen is used as a binder, which in the presence of an open flame can ignite at its own temperature of 250-300*C.

Order 43

6.2. When carrying out work on the preparation of black crushed stone, one must comply with the requirements of building codes and rules for safety in construction, set out in SNiP Sh - 4-80, as well as in the “Rules for labor protection in road construction”, M, Stroyizdat, 1989 .

Circulation 1000

Printing house of the State Supply Committee of the Russian Federation

Do it yourself

It is possible to make black crushed stone with your own hands. Crushed limestone of a grade of at least M600 and a fraction size of 20-40 mm is best suited for this. This choice is due to the ability of the materials to absorb binders better than other varieties.

Limestone crushed stone 20-40 close-up. Photos of Soil Trucks

Technologies and production methods, composition

As a raw material for the production of black mixture, not only crushed stone is used, but also rock minerals, as well as screenings from their crushing. For production, the enterprise selects rocks with a tensile strength of at least 80 MPa. The typical composition of the mixture includes a filler in the form of crushed stone and a binder. The ratio of components is 96-98 to 4-2%.

Materials of the following fractions are used as filler , as well as a combination of grains of size 5-20 and 5-40. Tar, petroleum road bitumen, and bitumen emulsions are used as binders.

General information about black crushed stone

Black crushed stone (black crushed stone mixture) is an artificial road-building material obtained by mixing granite, gravel or limestone crushed stone with viscous or liquid organic binders (petroleum road bitumen, bitumen emulsion or tar).

The so-called “terricone or coal crushed stone” (obtained by processing mine coal dumps), as well as painted decorative crushed stone or asphalt chips (milled or crushed asphalt concrete granules) should not be confused with black crushed stone

Purpose and scope of black crushed stone

The main purpose of black crushed stone mixtures is the construction of structural elements of road pavement: road bases and lower layers of road surface. In some cases, black crushed stone mixture can be used to create the top layers of road surfaces (temporary driveways and service roads), as well as as a material for surface treatment of asphalt concrete pavements.

Black crushed stone is used in the construction of roads of I–V categories, carrying out patching and major repairs of highways, when paving underground parking lots and parking lots, pedestrian crossings and other objects protected from moisture and direct sunlight. In addition to road construction, various types of black crushed stone mixtures can be used in the hydraulic engineering industry and civil engineering.

Typical composition and production technology of black crushed stone mixtures

The typical composition of a black crushed stone mixture includes two main components: a mineral filler in the form of crushed stone and an organic binder.

There are two technologies for preparing black crushed stones: the “mixing method” and the “impregnation method.”

The fundamental difference between the “mixing method” and the “impregnation method” is that in the first case, crushed stone is forcibly mixed with binder in a mixing plant, after which it is delivered by dump trucks to the work site and laid. In the second case, the already laid and compacted layer of crushed stone is treated with a binder component in order to impregnate it to a certain depth.

Classification of black crushed stone

By fraction size

Indication of the size of the crushed stone fraction, as a rule, is reflected by a numerical value in the name of the brand of black crushed stone mixture, for example: ShchChR-10 - fraction 5-10 mm, ShchChR-20 - fraction 10-20 mm.

By mixture temperature

Features of application

As a road surface, black crushed stone is used in a certain order. There are special requirements for such work:

• the place is pre-cleared;
• the top part of the soil is removed using special equipment;
• then a leveling layer is laid, the earth is compacted in the desired area;
• after this, the site is covered with sand and gravel to avoid cracking.

In some cases, the construction of the road base is carried out using the hot method and involves wedging. The installation temperature is important here, since it is necessary for the structure to become monolithic.

Areas of application

The material is the best option for road construction work . With the help of black crushed stone mixture, if all recommendations are followed, it is possible to obtain a strong, durable, wear-resistant coating . Crushed stone is also used for the construction of foundations, laying sidewalks and platforms, making asphalt concrete mixtures, arranging the top layer of the blind area around the house, and organizing a parking space.

Laying technology, construction of coatings and foundations

The preliminary stage of work is the preparation and registration of permits. The work begins with the preparation of the construction site, the top layer of soil is removed with a bulldozer bucket, the kidney is leveled and compacted, a layer of sand is spread, the embankment is compacted with a roller and moistened.

Reference. To increase the strength of the coating and prevent the formation of cracks, a gravel cushion is installed.

There are two ways to arrange road bases using black crushed stone - with and without wedging.

Reference. Wedging (or wedging method) is the wedging of large fractions of crushed stone into smaller ones. For example, materials 20-40 are wedged in grains of 10-20 mm, which are wedged in fractions of 5-10 mm. The result is a multilayer base of different fractions.

The most widely used method is the wedge method; the coatings created with its help are distinguished by their solidity. The order of work is as follows:

• treating the underlying surface with a binder using asphalt;
• 40-70 is used as the main fraction if the coating thickness is more than 80 mm, and 20-40 if less;
• distribution and compaction of sequentially crushed stone of fractions 20-40, 10-20 and lastly 5-10; distribution is carried out using a crushed stone spreader or a conventional asphalt paver.

Reference. Decluttering must be carried out especially carefully, based on designs and accurate calculations, taking into account the climate zone and weather conditions at the time of work, terrain, groundwater level and soil mobility.

The use of black crushed stone in road construction

To create road bases

There are two ways to construct road bases using black crushed stone mixtures: “with splintering” and “without splintering.”

Wedging (“wedging method”) is the sequential wedging of large fractions of crushed stone into smaller ones. The 20–40 mm fraction is wedged by the 10–20 mm fraction, which in turn is wedged by the 5–10 mm fraction. Thus, a three- or four-layer base of different fractions is obtained, while the 40–70 mm fraction can act as the main one.

Without decluttering, foundations are constructed using a mixed fraction of 5–20 mm or 5–40 mm.

The procedure for carrying out work on the installation of a black crushed stone base “with jointing” is as follows:

As the main one, it is allowed to use a fraction of 40-70 mm if the layer thickness is more than 8 cm. In this case, the first proppant fraction will be 20-40 mm, the second - 15-20 mm or 10-20 mm, the third - 5(3) –10(15) mm.

Distribution of black crushed stone mixture over the surface is carried out using a self-propelled, trailed, semi-trailer or mounted crushed stone spreader (or a conventional asphalt paver).

In the case of preparing black crushed stone at the work site using the “impregnation method” (rather than delivering the finished mixture in dump trucks), it is not the finished black crushed stone mixture that is laid, but ordinary crushed stone. After spreading and compacting each layer, it is treated with a binder using a self-propelled asphalt spreader. Laying of crushed stone can be carried out with a bulldozer, motor grader or crushed stone spreader.

For the installation of lower layers of road surfaces

Black crushed stone mixtures are used to create the base layer of the road surface during the construction of a new road or as a base leveling layer during the process of repairing the roadway. For these purposes, black crushed stone of fractions 5–10, 10–20 and 20–40 mm is used (fraction 40–70 mm is not used). The typical thickness of the black crushed stone layer of the road surface is from 40 to 80 mm.

For the installation of top layers of road surfaces

One of the main disadvantages inherent in black crushed stone is its low water resistance. In this regard, this material is practically not used for the construction of top layers of road surfaces.

Black crushed stone as a material for paving (as a rule, fine-grained grade ShchChR-10) can be used when constructing coatings on objects protected from rain and direct sunlight. Such objects may include underground pedestrian crossings, underground parking lots and parking lots, closed technological areas, hangars, etc.

The use of black crushed stone mixture as a material for the construction of upper layers is also permissible on roads of 3-4 technical categories (for example, logging roads) and for strengthening roadsides.

For surface treatment of asphalt pavement

Fine-grained black crushed stone of the 5(3)–10 mm fraction is used for processing cast asphalt concrete pavements using the “embedded method”. The surface treatment procedure is the final stage of the general cycle of work on laying a cast asphalt concrete mixture and is carried out with the aim of giving the road the required friction characteristics (roughness and a given coefficient of adhesion).

Technologically, the process of surface treatment using the “embedding method” comes down to uniform distribution over the surface and pressing (embedding) of black crushed stone into the already laid cast mixture.

In addition to the construction of cast asphalt concrete pavements, black crushed stone is used to create thin protective microsurfaces made from fine-grained mixtures using bitumen-crushed stone distributors.

Source

Kinds

There are several criteria according to which classification is performed:.

First, this is the faction:

• small - 5-10 and 5-20 mm, used for laying the top layer;
• medium - 20-40, is the most popular variety;
• large - 40-70, requires wedging.

A separate category also includes a mixed type of crushed stone, which is a mixture of fractions of different sizes.

Secondly, the temperature of the mixture:

Crushed gravel. Photos of Soil Trucks

1) Hot crushed stone is produced at a temperature of 120 to 160 degrees, laid at 100-120. The manufacturing technology includes drying of crushed stone, heating of crushed stone and a binder composition, which is used as bitumen of the BND, BN and SG types, D-6 tar, dosing the components into the mixer and mixing. Laying the hot mixture is carried out in dry weather in the spring at an air temperature of at least +5 degrees Celsius or in the fall at +10 or more.

2) Warm is produced at a temperature of 80-100 degrees, laid at 60-100. BND (road-petroleum) and BN (petroleum) bitumens and D-5 tar are used for production. Laying should be done in dry weather, at an air temperature of -10 to -5 degrees.

3) Cold can be produced with or without heating, depending on the type of binder component. When using emulsions, heating is not performed, bitumen SG (medium-thickening) or MG (slow-thickening), as well as tar D-3 and D-4 - heating is carried out to 90-120 degrees. Laying is carried out after cooling, at a temperature equal to the ambient temperature. Laying work should be carried out in dry weather in spring (temperature at least +5) and autumn (+10). Cold black crushed stone, unlike the first two types, can be stored for several months, but is inferior to them in water resistance and wear resistance.

Depending on the type of raw material, crushed stone is divided into materials from sedimentary, igneous and metamorphic rocks . In some cases, black crushed stone mixture is made from gravel, which is inferior in wear resistance and water resistance to crushed stone. Gravel, granite, and limestone crushed stone are also used as raw materials for the production of black mixture.

What kind of material is this

Black crushed stone (alternatively called black crushed stone mixture) is a sought-after artificial road building material. The product is produced by mixing crushed stone with binding components.

Reference. Black crushed stone should not be confused with other similar varieties:

• waste heap (or coal), obtained by processing mine coal dumps;
• dark-colored crushed stone, granite, gravel, and marble are used as raw materials;
• black decorative crushed stone - dolerite, which is a durable mineral of igneous origin, which is rare and therefore sold at high prices;
• asphalt crumbs - milled or crushed asphalt concrete fractions up to 40 (25) mm in size.

Advantages and disadvantages

Treatment of crushed stone with binders increases wear resistance and adhesion - the ability of materials to adhere to other building compounds. It is also possible to note the following advantages of using the mixture :

• ability to withstand significant external loads;
• does not create cracks in coating layers;
• good slip resistance;
• resistance to longitudinal shear of the coating;
• compaction ability;
• installation work can be carried out at any time of the year;
• long shelf life.

As disadvantages, it is possible to note water permeability and the duration of work on forming the coating, depending on weather conditions.

Construction of crushed stone foundations using the wedge method

• •Federal Agency for Education
• •Voronezh 2010 Federal Agency for Education
• •Road category on the “Don” road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •On the road “Don” Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •The roadway along the “Don” road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •Strengthening roadsides (on the right) along the Don road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •Longitudinal slope along the Don road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •Radiuses of curves in plan along the Don road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •Evenness indicator on the “Don” road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •Adhesion coefficient on the Don road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •Recreation areas
• •Sidewalks and pedestrian paths along the Moscow-Voronezh-Rostov-on-Don-Novorossiysk road
• •Marking on the road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •Lighting along the Don road Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •Road signs on the road “Don” Moscow-Voronezh-Rostov-on-Don-Novorossiysk
• •2. Organization and technology of construction control and acceptance work
• •2.1. Types of construction control
• •Construction of subgrade
• •Preparation of the subgrade base
• •Development of excavations and construction of embankments
• •Finishing and strengthening works
• •Earth work in winter conditions
• •Work quality control
• •Work quality control
• •Construction of crushed stone foundations using the wedge method
• •Work quality control
• •Bases made of crushed stone-sand mixture treated with cement
• •Features of the base structure in two layers
• •Quality control of construction materials
• •Work quality control
• •Asphalt concrete bases and coatings, laying asphalt concrete mixtures
• •Work quality control
• •0 0С (according to GOST 11501-78*);
• •0 0С (according to GOST 11505-75);
• •3.1. Preparatory work.
• •3.2. Organization of field work.
• •3.75 For roads of I…II categories;
• •3.5 For roads of III category;
• •3.0 For roads of IV-V categories.
• •3.6. Visual assessment of the condition of the road pavement.
• •3.7. Assessment of the strength of road pavements.
• •3.8. Determining the condition of engineering equipment and facilities (including intersections and railway crossings).
• •3.9. Determination of the intensity and composition of traffic flows.
• •4.1 Calculation of the partial coefficient Крс1.
• •Statement of results of determination of Krs1
• •Statement of results of Krs2 determination
• •Statement of results of determination of Krs3
• •Statement of results of Krs4 determination
• •Statement of results of Krs5 determination
• •Statement of results of Krs6 determination
• •Statement of results of determination of Krs7
• •Statement of results of determining the condition of road pavement and road surfaces8
• •Statement of results of Krs9 determination
• •Statement of results of Krs10 determination
• •Statement for assessing a complex indicator on typical sections of a highway
• •Determination of the partial coefficient DD
• •Determination of partial coefficients Dm1 – Dm7
• •Sheet for assessing the performance of engineering equipment
• •Calculation of justification for the cost of work for 2015. Over 20,059 km of survey
• •Planned cost calculation for performing work on diagnostics of federal highways in 2015
• •6. Ecology
• •6.1. Roadside soil contamination by vehicle emissions of lead General information
• •6.2. Methodology for assessing the level of contamination of roadside lands by lead emissions from cars.
• •1. Lead emission is determined by the formula:
• •6.3. Average operational fuel consumption rates per 1 km of travel in liters
• •6.4. The amount of lead deposits on the ground surface for various distances from the edge of the roadway is determined by the formula:
• •6.5. Determination of the amount of lead in soil:
• •Initial data:
• •We determine lead emissions for each site
• •7.1. General instructions for use
• •7.2. Indication of safety measures
• •7.3. Indication of safety measures
• •Pkrs node
• •7.4. Calculation of emergency braking.
• •7.5. Technical data of the mobile road laboratory:
• •Hence the visibility distance from the overtaking condition:
• •The functionality of the video system is significantly higher than the capabilities of any currently existing tool designed for surveying roads and streets
• •Collection of information
• •Measurement of road visibility distances in plan

Volumetric weight by fractions

Since crushed stone has a rough surface, it is characterized by excellent adhesion with a solution made from cement and sand. As a result, the presented product is simply irreplaceable in the construction of foundations, railway embankments, and road construction.

The density of crushed stone is one of the most important parameters on which strength ultimately depends. This criterion is calculated as the ratio of weight to the volume occupied by the material. This way we can find out how much a cube of crushed stone weighs. The units of measurement for this product are kg or t per m3.

The volumetric mass indicator for crushed stone is different and depends on what rock is used to obtain the material. For example, 1 m3 of granite has a mass of 2600 kg, and dense limestone - 2700-2900 kg. This difference in weight is explained by different amounts of dolomite impurities and other mineral components.

There is air between the crushed stone grains. For this reason, 1 m3 with voids can have a mass that will be equal to the volume of uncrushed rock. As a result of this, an indicator such as the bulk density of the material is used. This physical indicator means the ratio of the total weight to the volume that it occupies in its natural form. The density depends on the fraction, because the finer the grains, the higher the bulk density. You can find a table with crushed stone fractions according to GOST.

The video shows the volumetric weight of crushed stone:

In addition, density is taken into account in the following cases:

1. When the concrete solution gains strength. The higher the density, the less cement is needed. As a result, you will be able to save money.
2. During transportation. To calculate the carrying capacity and the need for transport, taking into account the dimensions of its body.
3. During storage and warehousing. In this case, the density allows you to determine the dimensions of the storage.

Find out at what temperature bricks can be laid.

You can read which is better: logs or laminated veneer lumber?

Dimensions of one-and-a-half solid bricks: https:///kirpich/kladochnyj/polutornyj-razmer.html.

To calculate the volumetric mass, it is necessary to use special containers in the process, the volume of which should be up to 50 liters. In addition, the container must have a certain shape. These containers are sent for weighing before and after filling from a height of 1 m, as well as leveling them level with its top. One of the important indicators for these measurements will be the compaction coefficient.

The difference obtained from these results takes part in the calculations. Here you will need to divide it by the volume of the container. Ultimately, you will be able to obtain the bulk density of crushed stone, expressed in kg/m3. After such an experiment, all data is included in the batch quality passport. All these studies must be carried out in a special laboratory where all the conditions and necessary equipment are available.

The main differences between crushed stone and gravel can be found in this article.

The volumetric mass indicator for crushed stone of different fractions has its own:

1. Granite –20-40 – 1370-1400 kg/m3, 40-70 – 1380-1400 kg/m3, 70-250 – 1400 kg/m3.
2. Gabbro-diabase – 1440-1580 kg/m3;
3. limestone –10-20 – 1250 kg/m3, 20-40 – 1280 kg/m3, 40-70 – 1330 kg/m3;
4. Gravel –0-5 – 1600 kg/m3, 5-20 – 1430 kg/m3, 40-100 – 1650 kg/m3, more than 160 – 1730 kg/m3;
5. Slag – 800 kg/m3;
6. Expanded clay – 20-40 – 210-340 kg/m3, 10-20 – 220-440 kg/m3, 5-10 – 270-450 kg/m3;
7. Secondary – 1,200-3,000 kg/m3.

During grinding of crushed stone to obtain the required fractions, the density of the material will take an average value between small and medium-sized grains. In this case, the volumetric mass can be 1.6 t/m3. Here it is imperative to take into account the bulk form of the product, which depends on the fraction of crushed stone and is called bulk density.

When determining the required volume of material for performing certain construction work, the volumetric mass of the product in dry form is used. Now the parameter will be called bulk mass. In the case of preliminary calculations, the average value of bulk weight is taken: volume 1 m3 = 1.6 tons.

Table of bulk mass per cube

Table 1 – Bulk mass of crushed stone by fractions

The specific gravity of crushed stone can be viewed at the link.

Manufacturing and use

Laying asphalt with black crushed stone

The process of manufacturing the material is carried out at asphalt-concrete plants (ACB), with the exception of the cold-type production process using emulsions, in mixing plants of various designs (forced or free mixing).

When producing black crushed stone, rocks with a tensile strength of 80.0 MPa are usually used. The ratio of crushed stone and binders is 96 – 98/4 -2%, respectively.

The use of this material in the construction of roads and coverings for other purposes is widespread in practice. To strengthen the laid layers, the wedging method is used.

When constructing a wedge, crushed stone of small and large fractions is used, which are mixed before laying on the surface. When mixing fractions, small grains of crushed stone are placed between large ones, thanks to this, after compaction, the surface becomes smooth and durable.

Composition and method of preparing black crushed stone

To build roads, it is necessary to use materials that ensure adhesion of the asphalt surface to car tires. For this purpose, black crushed stone is used, which is crushed stone treated with tar or bitumen emulsion using special technology. Obtaining new properties (adhesion, wear resistance), it can also be used for constructing foundations, laying alleys and sidewalks, and producing asphalt concrete mixtures.

Black is ordinary or fractional crushed stone, differing in the method of production and laying: cold, warm and hot. Based on grain size, they are distinguished:

Difference from decorative stone

There is also dolerite crushed stone - this is a rock of igneous origin, dark gray or black in color, characterized by high mechanical strength; when precipitation falls on the surface, a gloss is formed. Used as a finishing stone, used in landscape design and garden architecture. You can buy dolerite crushed stone 12-20 mm black from 85,000 rubles per 20 kg, as this is a very rare specimen.

What happens?

Black crushed stone, fractional or ordinary, differs not only in the type of preparation (cold, warm and hot) and installation, but also in the size of the shaped inclusions:

• may contain large grains ranging from 40 to 70 mm;
• medium - fractions from 20 to 40 mm;
• small inclusions, that is, crumbs from 5 to 15 mm.

The most popular is crushed stone with medium grain sizes. The most expensive is hot black crushed stone, which has high wear resistance, strength and adhesion. In contrast, the cold type of building material does not have such qualities, but can be stored for up to six months without sticking together.

There is also a decorative type of crushed stone - dolerite, a high-strength rock, the peculiarity of which is a glossy surface, which allows the use of a rare stone for artistic decoration of the local area. This is expensive crushed stone, which, using advanced technologies, is painted in any desired color, and is intended for beautifying garden areas - paths, lawns and flower beds. Images and drawings can be applied to this material, or processed in other ways.

Types and applications

According to GOST, black crushed stone is classified by fraction size:

1. From 5 to 20 mm – gravel screenings (crumbs), which is the finest-grained composition.
2. From 20 to 40 mm – medium-grained crushed stone. Most often used in construction.
3. From 40 to 70 mm - coarse-grained material, during the laying of which declinging is usually performed (redistribution of stone to remove voids).

The specific gravity of black crushed stone is 2.9 t/m3, so it is transported only by heavy-duty vehicles.

Most often, this material is used when laying sidewalks, city alleys and playgrounds. Asphalt concrete road surfaces are also made from it. When building houses with basements or basements, raw materials are used for waterproofing.

Sometimes this unusual material is used for decorative decoration of suburban areas.

The bulk density of black crushed stone is 2900 kg.

Cold production technology

This black crushed stone is used only for repairing road surfaces. Cold production technology is carried out in two ways: directly on site or in a special installation with subsequent transportation to the work site.

Such raw materials are prepared using tar, bitumen and their emulsions at temperatures from +100C to +200C. The resulting material is laid cold. In this case, a necessary condition is the air temperature, which should not be lower than +5C.

Cold crushed stone has a low viscosity, so it can be stored in cold rooms for a long time.

Time standards and prices per 100 sq. m of base or covering

table 2

Scope of work:

1. A scattering of wedge or stone chips (treated or not treated with bitumen) along the roadway with a toe of up to 5 m
2. Sweeping material with brooms

Technologies for manufacturing and laying black crushed stone coatings

The manufacturing process, requirements for the composition of black crushed stone and the final characteristics of the product are established by GOST 8267 and 3344, tests are carried out for compliance with the characteristics of the Interstate Standard GOST 30491-2012. The difference between the properties of the composition and the technology for its installation depends on the use of certain binders and the manufacturing method. Depending on these features, it is customary to divide black crushed stone into types:

• hot technology - the binder is heated to 120 - 160 °C, laying is carried out at 100 - 120 °C, impregnation is carried out with medium-thickening bitumens and tar;
• warm technology - petroleum bitumen or tar D-5 is applied to the crushed stone when heated to 80 - 120 °C and then laid with a minimum period of time and a temperature of 60 - 100 °C;
• cold technology - impregnation is carried out without preheating using liquid bitumen and D-3 tar.

Cold black crushed stone becomes of great value in cases where it is necessary to store the material for a long time before use. The composition does not stick together, unlike warm and hot crushed stone, it can lie in a covered warehouse for up to six months. However, the adhesive properties of this composition are much lower, so it is used with restrictions when it is possible to save money by selecting a material taking into account the reduced design load on the web.

What is black crushed stone

The technology for preparing black crushed stone makes it possible to reduce the water absorption of crushed rocks and increase their wear resistance and adhesion. This building material is used for arranging foundations, laying roads and decorative areas, and creating asphalt concrete mixtures. It has a black color due to treatment with bitumen or tar emulsions, other properties (fraction size, flakiness) remain practically unchanged. The average volumetric weight of such crushed stone varies from 1.6 to 2.6 t/m3, strength grade - from M300 to M1200, the specific choice depends on the type of construction work.

For production, crushed rocks are used, which are enveloped in organic binders at a special temperature. Processing takes place in forced-action asphalt mixing plants or in rotating drums. Depending on the type of technology, crushed stone and binder are heated and dried, or simply mixed in a cold state (emulsions are used). The percentage of liquid or viscous organic matter in both cases rarely exceeds 4%. Black crushed stone obtained by the hot method is most often used immediately; if storage is necessary, it must be cooled and treated with special compounds. Filler impregnated with emulsions is also divided into stored and quickly laid, each brand has its own shelf life.

Based on the size of the fractions, there are:

The first type requires wedging, the second is the most popular, and the last is a crumb that is part of mixtures or laid as a top layer. Depending on the type of raw material processed and strength, black crushed stone is divided into: basalt (from M800), from sedimentary, igneous and metamorphic minerals (from M300). In some cases, it is made from gravel, but such a filler is inferior in wear resistance and water resistance to crushed stone. The lower quality of black gravel is due to the poor adhesion of bitumen and smooth surfaces. Therefore, it costs less, and to improve adhesion, crushed rocks are introduced into the composition.

Depending on the manufacturing technology, black gravel and crushed stone are divided into:

Features and Specifications

When purchasing, pay attention to the strength of black bitumen crushed stone, the size of the fractions, volumetric weight and composition. Depending on the manufacturing method, each brand is laid under certain temperature conditions. Cold crushed stone is stored better, but is inferior in water resistance and wear resistance. The deeper the binder penetrates into the black filler, the higher its adhesion, and the more difficult it is to preserve it (it simply sticks together, even when cooled).

The material is considered optimal for road construction work. In this case, first the coarse filler is poured, then the finer ones are filled in using rollers. Crushed stone impregnated with bitumen, laid using the wedging method, creates a durable, strong and wear-resistant coating. This laying technology requires control of the thickness of each layer and the temperature of the material. It is also common practice to backfill this crushed stone as a cushion when constructing buildings in areas with a high risk of groundwater flooding.

There is no need to confuse crushed rocks treated with bitumen with black decorative crushed stone - dolerite, which is a high-strength mineral of igneous origin that forms a gloss when in contact with water. The latter quality is highly valued in landscape design, but due to its rarity, dolerite is expensive - from 4,250 rubles per 1 kg. The price of ordinary crushed stone or gravel depends on the strength and size of the fractions. The material can be purchased in bags or in tons. If you need to find out the cost of m3, then you should divide the amount per 1 ton by the conversion factor (volume weight).

Characteristics and density of black crushed stone

The ratio of impregnation and stone component of black crushed stone is in the range of 2 – 4.5% of the binder. The density of black crushed stone directly creates the conditions for the successful completion of the task - creating a durable canvas. For the calculation, the ratio of the mass of the material to the volume after completion of impregnation is taken. During the laying process, larger coarse and medium fractions (40 - 70, 20 - 40) are first used, after which the web is wedging with fine material and final rolling. The original granite crushed stone must have a frost resistance index of at least F15 cycles. Optimal strength indicators are selected from a wide range from M300 to M1200.

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Characteristics: density, specific gravity and others

1) Bulk density (or specific gravity) depends on the size of the fractions: for small ones the figure is 2600 kg/cub.m. and for large ones - 3200.

2) Strength , crushability grades - from M300 to M1200, the choice depends on the specifics of the work. For example, for bases it is recommended to use crushed stone with a grade of at least M300 for fine-grained materials and M400 for medium- and coarse-grained materials, and for impregnation of the coating - M300-400 and M400-800, respectively.

3) Frost resistance. The minimum level of black crushed stone must correspond to grade F15. If the mixture will be used for impregnation, then F25.

Crushed stone is one of the components of asphalt concrete. Photos of Soil Trucks

4) The content of needle-shaped and plate-like inclusions should not exceed 25% for crushed stone intended for impregnation and 35% for the construction of coatings.