Natural Materials
All materials in construction are obtained from nature and mines, and after chemical changes, they become desired materials and materials and the same materials that you see today. In other words, today, with the advancement of industry and technology, the type of construction materials has changed from traditional to modernity, and we are also witnessing fundamental changes in the structure and appearance of many of them, especially the materials used in the facade, such as brick and stone. Maybe there has been no change in the basis of their use; But we can safely say that their appearance has changed a lot compared to the past.
General Properties of Building Materials
- Chemical properties
- Physical properties
- Architectural properties
- Mechanical properties
- Costs and economic issues
- Functional properties
physical properties of building material
1- Water absorption ability
One of the characteristics of good building materials is that it absorbs water vapor from the air. This property depends on the air temperature and relative humidity, the type of pores, their number and dimensions, and finally on the nature of the material in question.
The surfaces of some materials are known as water retaining or hydrophilic and Some others also repel water. Water-retaining materials (hydrophilic) are prone to disintegration in water, while water-repellent materials strongly resist the effects of water and its accompanying materials.
2- Sertabi
One of the characteristics of good building materials is that it shows the ability to withstand high heat of the material for a long period of time without melt or lose its appearance.
3- Specific surface area
In general, it can be said that the total surface area of one gram of matter It is called specific surface in square centimeters. This feature is very important in materials such as soil, plaster and cement. Because the more specific surface they have, the contact surface of the seeds with water will increase and a better result will be obtained when using. 4- Softness coefficient For some materials that strongly absorb water and are greatly affected by it, such as clay, it is close to zero, and against it, the softness coefficient of materials that maintain their resistance under the influence of water, such as glass and Metals are equal to the number one. In other words, it can be said that construction materials with a high softness factor of 0.8 are known as waterproof materials.
chemical properties of building materials include
1- Durability and stability
Durability and chemical stability of building materials (oxidation or rusting, corrosion) against the effect of acids and bases, the effect of water, the effect of oils, the effect of salt Sulfates, sulfurs, chlorates, chlorides, nitrates can be mentioned. Sometimes they release heat and sometimes they absorb heat. In such cases, the necessary precautions must be taken so that the heat released or absorbed does not interfere with the materials. For example, it can be said that the setting process of cement is exothermic and the production of building adhesives is exothermic. 3- Crystallization Crystallization is another feature. are the chemical properties of building materials. In the definition of crystallization, it can be said that the tendency of a substance to form a crystal, which occurs in the process of transition of that substance from fluid state (gas or liquid) to solid state.
Mechanical Properties of Building Materials
1- Strength
Compressive strength, tensile strength, shear strength, torsional strength, bending strength (hammerability property)
2- Hardness< 3- Wear resistance 4- Mechanical deformation The deformation of the material according to the applied load (moldable, fixed shape, changes over time , property of truncation)