In the vast and complex system of the construction industry, chemical raw materials are like key links, closely connecting various links and playing a diverse and irreplaceable role. From the initial production of building materials, to the steady progress of construction processes, and to the maintenance and upkeep of buildings in the later stages, chemical raw materials inject a continuous stream of power into the booming development of the construction industry due to their unique properties.
Chemical raw materials in the production of building materials
(1) Chemical raw materials in cement production
Cement, as a fundamental material in the construction industry, relies heavily on chemical raw materials in its production process. Among numerous chemical raw materials, gypsum is an extremely important retarder. During the hydration process of cement, without the intervention of gypsum, its setting speed will be extremely fast, which will greatly affect the construction operation. For example, in the concrete pouring project of large commercial complexes, the pouring volume can reach thousands of cubic meters at once, and the pouring time may last for several hours or even days. If the setting time of cement is too short, some concrete may harden during the pouring process, resulting in uneven filling of the formwork and ultimately affecting the overall integrity and stability of the building structure. After adding an appropriate amount of gypsum, it will react with tricalcium aluminate generated by cement hydration, forming a insoluble protective film on the surface of cement particles, thereby delaying the hydration process of cement and obtaining sufficient operating time for construction personnel.
In addition, fluorite plays an important role in the cement clinker firing process. The firing of cement clinker requires a high temperature environment, and adding fluorite as a mineralizer can reduce the firing temperature of the clinker. This not only saves a lot of energy, but also promotes better formation of mineral phases in cement clinker. Taking Portland cement clinker as an example, appropriate firing temperature and use of mineralizers can make the crystallization of major minerals such as tricalcium silicate and dicalcium silicate more complete and the crystal structure more stable, thereby improving the strength of cement and enabling it to withstand greater loads in construction projects.
(2) Chemical raw materials in plastic building materials
With the increasing demand for energy-saving, environmentally friendly, and multifunctional materials in the construction industry, plastic building materials have ushered in broad development space. Polyvinyl chloride (PVC), as the main raw material for manufacturing plastic pipes, door and window frames, and other products, has many excellent characteristics. Taking plastic pipes as an example, compared with traditional metal pipes, PVC pipes are lightweight and have a density of only about one-fifth of steel, which greatly reduces the investment in manpower and machinery during pipeline installation. Moreover, PVC pipes have excellent corrosion resistance, which can effectively resist the erosion of chemical substances whether transporting industrial wastewater containing acid and alkali components or in humid underground environments, greatly extending the service life of the pipes. According to statistics, under normal usage conditions, the service life of PVC plastic pipes can reach more than 50 years, which reduces the cost and resource waste caused by frequent replacement compared to metal pipes.
Plasticizers and stabilizers are indispensable chemical raw materials in the production process of PVC plastics. Phthalate plasticizers can be inserted between PVC molecular chains, weakening the intermolecular forces and making PVC plastic soft and elastic. They are suitable for manufacturing products such as plastic films and soft pipes. Lead salt stabilizers, on the other hand, inhibit the thermal degradation reaction of PVC by absorbing the hydrogen chloride generated during its degradation process, ensuring the stability of hard PVC products during high-temperature processing and long-term use. They are commonly used in the manufacture of door and window frames, drainage pipes, etc.
Chemical raw materials in building maintenance
(1) Waterproof sealing material
The waterproof sealing work of buildings is directly related to the structural safety and functional use of buildings, and chemical raw materials play a dominant role in waterproof sealing materials. SBS modified asphalt waterproofing membrane is a widely used waterproofing material. Among them, SBS (styrene butadiene styrene block copolymer) as a modifier can form an interpenetrating network structure with asphalt, significantly improving the elasticity, toughness, and high and low temperature resistance of asphalt. In roof waterproofing engineering, SBS modified asphalt waterproofing membrane can effectively resist the infiltration of rainwater, even under the alternating effects of high temperature exposure in summer and low temperature freezing in winter, it can still maintain good waterproof performance. For example, in the roof waterproofing renovation project of a large industrial plant, 4mm thick SBS modified asphalt waterproofing membrane was used. After years of use, there was no leakage on the roof, ensuring the normal operation of equipment and smooth production activities in the plant.
Silicone sealant is not only used for bonding in construction, but also commonly used for sealing and waterproofing building gaps during maintenance. If the gap between the door and window frames and the wall is not effectively sealed, rainwater will seep into the room through the gap, causing problems such as mold on the wall and corrosion of doors and windows. After sealing with silicone sealant, a tight waterproof barrier can be formed, while also preventing air infiltration and improving the energy-saving effect of the building. According to tests, after using silicone sealant to seal the gaps between doors and windows, the air permeability of the building can be reduced by more than 30%, effectively reducing the loss of indoor heat and lowering the energy consumption of air conditioning and heating systems.
(2) Anti-corrosion coating
For building structures in harsh environments, such as chemical plants, coastal buildings, etc., anti-corrosion coatings are the key to ensuring the service life of buildings. Zinc rich primer is a commonly used anti-corrosion coating, and its main component, zinc powder, has an electrochemical protective effect. After applying zinc rich primer on the surface of steel, zinc powder acts as an anode and reacts preferentially with oxygen and moisture in the air, forming a dense zinc oxide protective film to protect the steel substrate from corrosion. In the maintenance of steel structure bridges, it is crucial to regularly apply anti-corrosion coatings due to the long-term exposure of the bridge to the natural environment and the repeated effects of vehicle loads. For example, a cross river bridge undergoes comprehensive anti-corrosion coating maintenance every 5 years after completion. By using zinc rich primer and matching intermediate and topcoats, the service life of the bridge is effectively extended, maintenance costs are reduced, and the safe operation of the bridge is ensured for decades.
The application of chemical raw materials in the construction industry is extensive and in-depth. From the production of building materials at the source, to the fine operation of the construction process, and to the maintenance and upkeep of the entire life cycle of buildings, chemical raw materials, with their diverse properties and continuously innovative technologies, continuously promote the construction industry towards higher quality, energy conservation, environmental protection, and innovation. With the continuous advancement of technology, chemical raw materials will undoubtedly show broader application prospects in the construction industry, helping to create a higher quality, comfortable, and safe building environment.