In construction, you can not do without drawings, among them there is also such an important element as the hatching of concrete and reinforced concrete. Let's try to figure out what this concept is, what features are inherent in it, and which design system should be followed.
The concept of "hatching" and design features of the drawings
The shading of concrete and other building materials is a symbol. Using shading in the drawings, the types of materials are determined. This is necessary for convenience in the construction of facilities for various purposes. However, the most frequently considered symbolic designation is applied specifically to concrete.
When drawing, use a pencil. The material designation consists of several components (strokes, lines and points) located at a certain distance from each other. Used items may overlap.
Schemes of this type are used in the implementation of most construction projects. But there are certain features that must be taken into account:
- hatching of concrete may be absent if it is not necessary to create it, or partially applied, in order to highlight a specific object;
- you can draw up the necessary number of additional drawings and display in them explanations for individual materials that were not taken into account when forming the standard.
Famous Notation Systems
There are several systems for construction:
- GOST 3455 - 59;
- GOST 2.306 - 68;
- GOST R 21.1207-97.
Let us consider in more detail each of the three systems and study the features of drawing a pattern inherent in each type.
Concrete shading according to GOST: GOST 3455-59 standard
This template was created in the 50s, they began to be used in drawings from 01/01/1959. The standard was valid until 01/01/1971. The drawings for engineering are considered in the system.
The designations were as follows:
- metals - denoted by oblique strokes, maintaining equal intervals between them;
- non-metallic materials for construction - applied in the form of lines, inclined to the right or left and intersecting at right angles;
- wood - designations were applied depending on the characteristics of the tree; cracks and rings - a transverse section was used as a designation; larch texture - fractional section;
- solutions - marked by hatching in the horizontal direction, while the gaps were tapering;
- glass - material was determined in the drawings by the presence of strokes of three types and different intervals - horizontal, vertical;
- hatching of unreinforced concrete was made in the form of sand gravel;
- brick - two types of lines were applied (solid, dashed), which intersected at an angle;
- reinforced concrete - designated by the image of sand gravel, slanting strokes;
- soil - in this case, sand gravel was applied, in addition, three intersecting lines located in two directions — vertical or opposite — were used.
GOST 2.306-68 standard: how it differs, how it is applied
As noted earlier, the previous standard was canceled in 1971. This system was replaced with the new character standard. What are the differences, and how is the hatching of concrete and reinforced concrete used in AutoCAD? Consider these issues and see how to designate building materials in accordance with the new standard.
The most important difference is rigor. The standard has been made simpler. The system of 1971 is not characterized by artistic effects, everything is clear and understandable. The innovations are as follows:
- wood - the designation is the same arcs located at equal intervals;
- natural stones - the stone in the drawings can be identified by the oblique dash;
- hatching of concrete - performed in the form of dashed lines, maintaining the same slope;
- soil - apply 3 strokes, which are a group with gaps;
- silicate, ceramic materials - building materials are designated by symbols of two groups; while between the strokes leave a large distance.
Accepted graphic designations allow you to display on the drawings the materials necessary for the construction of buildings and other objects. This is very convenient both in the manufacture of parts and in the creation of various designs.
Marks are made in the form of thin lines, carefully drawing them in the right direction and at a certain interval. Within one drawing, metal designations should always stand out from the rest of the building materials. That is, when designating these materials between the lines leave more space than when designating metals.
Parallel hatching lines are performed at the same intervals for the sections of a particular element, the scale of which coincides. For different cross-sectional areas, this interval is from 1 to 10 mm.
When a new standard is released, the old one is automatically canceled. The system of 1971 regulates the same sections of production as in the document of 1959. Moreover, the first version of the standard is invalid.
In this case, the system adopted in 1959 was considered in order to familiarize itself with all known standards.
Other features of the standard adopted in 1971
Other requirements are also provided. Such features of the standard are expressed in the following points:
- if the similarity of the figures that indicate different materials is noticeable, you can not do without additional information; explanations must be indicated without fail;
- in this standard there is no designation for reinforced concrete, therefore a separate template was created for it; designation designation features in the drawings are shown in GOST 21.107-78;
- facade materials do not fully display, in this case it is enough to partially fill the contour.
Rules prescribed by the 1971 standard
Concrete shading (GOST) in AutoCAD is performed according to the following rules:
- Small sections are marked with strokes. This designation is similar to metal. Another option is possible - do not mark on the drawings with strokes at all, indicating information about their presence in the marks.
- The lines that you want to place at an angle, follow the angle of 45 degrees. In this case, the angle can be determined, focusing not only on the framework of the drawing, but also on the outline of the figure or axis.
- In adjacent planes, lines should be placed at different angles.
- Both right-handed and left-handed hatching are possible, but the slope for all sections must coincide within the same part. It doesn’t matter if all the images of this part are placed on one sheet or several were required.
- Narrow sizes and cuts of large lengths do not have to be hatched along the entire length; hatching is possible only along the edges or in several places chosen arbitrarily. Cuts, the thickness of which does not exceed 2 mm, are noted completely.
The rules provided by the standard should be followed without fail.
GOST R 21.1207-97: latest innovations
As mentioned above, the 1971 standard had a significant drawback - the lack of a system for designating reinforced concrete. Only this was the reason for the compilation of GOST R 21.1207-97. In the following standard, the deficiency was eliminated, the required symbol was introduced.
Most often this template is used when road works are planned. In addition to soil and asphalt, other materials, in the document a special place is given to the following points:
- hatching of concrete according to GOST in "AutoCAD" - mark on the drawings with a dashed line;
- reinforced concrete designation - alternately use solid lines and lines that are interrupted;
- designation of reinforced concrete equipped with tensile reinforcement (a material that is stretched or heated and connected to reinforced concrete; such reinforcement is quite flexible) - two solid lines, then one dashed line, are used as a symbol, in turn
conclusions
The main goal when using concrete hatching in AutoCAD is the need to visualize, with the help of drawings, the objects whose construction it is planned to implement. Symbols greatly help in the implementation of this task.
Two standards are currently in force, both systems are used in engineering and construction. These standards allow builders to quickly determine the right materials when building objects.