As early as the primitive society, people lived in natural caves and tree nests in order to resist the rain, snow, cold and wild animals. In the Stone and Iron Age, people began to use simple tools to cut down trees and thatch, build simple houses, and dig stones to build simple houses and memorial structures. In the Bronze Age, there were wooden structures and "slab buildings", that is, buildings with wooden boards or sticks as the frame, then pouring soil into the frame, tamping it with a wooden pestle, and then removing the wooden boards. At this time, comfortable buildings have been built, mainly using natural materials such as natural stone, wood, clay and thatch.
After people can burn bricks and tiles with clay and lime with limestone, civil engineering materials have entered the stage of artificial materials from natural materials, and the main structural materials used are bricks, stones and wood.
brick
Brick is a common masonry material. The production and use of bricks and tiles have a long history in China, and they are known as "Qin bricks and Han tiles". The raw materials for brick making are easily available, the manufacturing process is relatively simple, the price is low, the volume is small, and it is easy to combine. Clay bricks also have the advantages of fire prevention, heat insulation, sound insulation and moisture absorption. Therefore, it is still widely used in masonry projects such as walls, foundations and columns.
Stoneboog
Natural stone is one of the oldest civil engineering materials, because it has high compressive strength, good wear resistance and durability; The resources are widely distributed, rich in reserves, easy to obtain local materials and low in production cost. It is the main material for building walls, bridges, houses, roads and water conservancy projects in civil engineering. For example, the pyramids in ancient Egypt, Zhao Zhouqiao in China and the Great Wall.
wood
Wood is one of the earliest civil engineering materials used by human beings, which has the characteristics of light weight, high strength, impact resistance, good elasticity and toughness, low thermal conductivity, strong texture and good decoration. However, it is anisotropic, which may be greatly affected by moisture content and natural defects, flammable and moth-eaten. Wood is easy to process, and the adverse effects of anisotropy, moisture content and natural defects on properties can be overcome or alleviated by processing. Therefore, wood has been widely used in ancient architecture and modern architecture. Wood is processed from trees, and there are many kinds of trees. According to tree species, wood can be divided into conifers and broad-leaved trees.
Conifer leaves are scaly or needle-shaped, mostly evergreen, with tall and straight trunk, smooth texture, uniform material and easy access to large trees. Its wood is soft and easy to process, so it is also called cork. Conifer wood has small apparent density and swelling deformation, high strength, high fat content and strong corrosion resistance. Mainly used as load-bearing components and furniture materials. Commonly used conifers are Korean pine, larch, spruce, fir and cypress.
Broad-leaved trees have broad leaves and reticulate veins. Mostly deciduous trees, the straight part of the trunk is short, the material is hard and difficult to process, so it is also called hardwood. Broad-leaved trees have high strength, obvious texture and beautiful patterns; However, the expansion and contraction deformation is large and it is easy to warp and dry. Usually used as smaller components and interior decoration. Commonly used broad-leaved trees are elm, birch, oak, Populus davidiana, Populus cathayensis and so on.
By the rise of capitalism in the 18 and 19 centuries, the old materials can no longer meet the new design requirements of civil engineering construction such as long-span factories, high-rise buildings and bridges, and civil engineering materials have entered a new development stage with the cooperation of other related science and technology. Accordingly, steel, cement, concrete, reinforced concrete, prestressed concrete and other materials have appeared.
steel products
Steel is widely used in railways, bridges, construction projects and other structural projects. It is produced under strict technical control conditions and has uniform and compact quality, tensile, compressive, bending and shear strength. It can bear large impact and vibration load at room temperature, and has certain plasticity and good toughness. Good processing performance, casting, forging, welding, riveting and cutting, convenient equipment, creating conditions for high-rise buildings with steel structure.
cement
Cement is a kind of hydraulic cementing material, which forms a plastic slurry after mixing with water, solidifies and hardens in air and water, and solidifies with other materials to form a hard stone. Portland cement, also known as Portland cement, is mixed with water for initial setting, final setting and hardening to form hard cement stone. In addition, there are fast-hardening silica gel salt cement suitable for emergency repair engineering, low-temperature engineering and high-grade concrete prefabricated parts; Quick-setting and quick-hardening portland cement used in emergency repair works such as military engineering, airport runways, bridges, tunnels and culverts; White cement for indoor and outdoor decoration; High alumina cement with fast hardening, high strength, heat resistance and corrosion resistance; Expansive cement used to make large-diameter water pipes and various oil and gas pipelines not only does not shrink but expands to some extent during the hardening process.
specific
Concrete is one of the most important civil engineering materials. It is an artificial stone which is made by mixing cementing material, aggregate and water in a certain proportion, stirring and vibrating, and curing under certain conditions. Concrete has the characteristics of abundant raw materials, low price and simple production technology, so it is used more and more. At the same time, concrete also has the advantages of high compressive strength, good durability and wide range of strength grades. According to materials, it can be divided into cement concrete, asphalt concrete, gypsum concrete and polymer concrete. In order to overcome the defect of low compressive strength of concrete, reinforced concrete, prestressed concrete and various fiber concrete have appeared by combining concrete with other materials.
Reinforced concrete refers to concrete made of steel bars, which overcomes the weakness of low tensile strength of concrete and protects steel bars from corrosion. Reasonable allocation of steel bars can give full play to the characteristics of high compressive strength of concrete and high tensile strength of steel bars, and at the same time bear loads to meet the needs of engineering structures.
Prestressed concrete generally refers to prestressed reinforced concrete, which generates prestress by tensioning steel bars. The use of prestressed reinforced concrete can improve the tensile capacity of products or components, reduce or delay the occurrence of cracks, make full use of high-strength materials, greatly improve the crack resistance, stiffness and durability of products or components, reduce their own weight and save materials.
asphalt
Asphalt petroleum is a mixture of some extremely complex polymer hydrocarbons and nonmetallic derivatives of these hydrocarbons. Asphalt can be used not only in road engineering, but also as waterproof material for building construction and anticorrosive material for general civil engineering.
plastic
Plastic is a kind of material based on organic polymer compounds, which is molded at a certain temperature and pressure after adding various modification additives. It has the advantages of low apparent density, poor thermal conductivity, relatively large strength and weight, good chemical stability, excellent electrical insulation, good sound attenuation and shock absorption, and decoration.
With the improvement of production requirements and environmental awareness, various new composite materials and green building materials came into being.
Colorbond sandwich board
Divided into color steel polyurethane sandwich panel and color steel polystyrene sandwich panel. The color-coated steel plate is used as the surface layer, and the core material is divided into polyurethane and polystyrene foam, which are compounded by a specific production process (dry compounding process). No matter what kind of sandwich panel, it has the characteristics of "three in one" and * * * working together. Color steel plate has the advantages of high strength, waterproof, good corrosion resistance and bright color, while foam plastic is light in weight, excellent in thermal insulation performance and can bear certain shear force. It is an ideal heat insulation material. Products are widely used in the rapid construction of light steel structure houses, insulated carriages, insulated and refrigerated carriages, as well as ordinary industrial and civil buildings.
green building materials
Green building materials refer to healthy, environmentally friendly and safe building materials, which are also called "healthy building materials" or "environmentally friendly building materials" internationally. Green building materials do not refer to individual building materials products, but to the evaluation of "health, environmental protection and safety" characteristics of building materials. In China, it is only known as a concept. Green building materials are building materials produced by clean production technology and industrial or urban solid waste. They have the properties of degaussing, silencing, dimming, temperature regulation, heat insulation, fire prevention and antistatic, and are special new functional building materials for regulating human body functions.
Civil engineering materials will be further improved and developed with people's needs.