| Selection and application of waterproof materials for road and bridge deck |
1】 Waterproof and impermeability 2] acid and alkali resistance 3] compressive strength 4] high temperature resistance 5] cohesiveness 6] frost and thaw resistance
Common diseases of national highway and bridge projects: expressway and high-speed railway are developing day by day. In the past few years, some traditional materials have caused high maintenance costs and structural damage. However, cracks, fractures, spalling, honeycombs, water seepage, leakage of reinforcement, insufficient load-bearing, etc. generally occur in roads and bridges. The reason is the lack of material durability and poor performance. As is known to all, reinforcement plays a role in structural tensile strength, while concrete provides structural compressive strength and protection for reinforcement. During the use of concrete, the physical, chemical and biological effects of the environment make the internal components of concrete react and denature, dissolve and precipitate, crystal expand, resulting in structural cracking, [ARS] corrosive corrosion, freeze-thaw damage, concrete cracks, etc., which not only reduces the performance of concrete, It will accelerate the damage of reinforcement in concrete and cause structural collapse.
Requirements for waterproof materials of Expressway and Bridge:
1】 Impermeability: determined by the structure of concrete and the natural environment, the internal voids of concrete will cause water, acid and alkaline pollutants to infiltrate into the concrete, resulting in rebar corrosion and concrete cracking. In order to prevent the corrosion of pollutants, waterproof materials must have good impermeability.
2】 Chloride ion resistance: chloride salt is the main product that destroys concrete. Environment: sea water, sea wind, snow melting agent, etc. once infiltrated, calcium chloride and crystal water will be generated, which will expand in volume and corrode the reinforcement, which will make the concrete crack. Therefore, good materials resistant to chloride ion must be selected.
3】 Compressive strength: the high-speed pavement bears the movement load, the paving asphalt, the temperature difference and the internal and external tensile stress. Therefore, the durable materials that enhance the compressive strength of the pavement and improve the service life of the concrete are selected.
4】 High temperature resistant type: the pavement is paved with asphalt, which is up to 150 degrees. In addition, there is vehicle motion friction, and the surface temperature is high in summer. To ensure the durability of the material, the material with high temperature resistance must be selected.
5】 Bonding performance: the pavement is multi-layered, and the waterproof layer should play a role of bearing, connecting each layer, and evenly transmitting the upper heavy pressure to ensure that the overall bearing capacity of the structure will not be damaged by the waterproof layer, and there will be no delamination between the asphalt layer and the structural layer. Therefore, the selective materials must have good bonding performance. Concrete permanent condensate DPS: it drives a series of physical and chemical cross chain reactions through penetration, and generates a water-based inorganic permeable protective layer integrating crack resistance, impermeability, reinforcement, wear resistance and self-healing of 0.3mm cracks. It is not only used for the water front surface, but also for the water back surface. It is a new high-tech waterproof material, which is incomparable with other materials
Application of goodcrete osmotic crystallization DPS in subgrade surface and bridge deck
Gudun architects analyze the importance of concrete anti-corrosion:
Concrete carbonation is the chemical corrosion of concrete. Carbon dioxide in the air enters the concrete and reacts with alkaline substances to generate carbonates and water, reducing the alkalinity to carbonation and neutralization. During the hydration process of cement, a large amount of calcium hydroxide is produced and filled the concrete pores. Its alkaline medium has a protective effect on the reinforcement, so that Fe2O3 and Fe3O4 are generated on the surface of the reinforcement and become a passivation film, After carbonization, the alkalinity of concrete will be reduced. When the carbonization exceeds the protective layer of concrete and there is water and air, the reinforcement inside the concrete will not be protected and the reinforcement will start to rust. It can be seen that carbonization will not directly affect the performance reduction and has no impact on plain concrete. However, the side effect on reinforced concrete is large and the alkalinity will be reduced, so as to enhance the hydrogen ion quantity of pore solution and make the concrete unable to protect the reinforcement, Especially in the seaside, the air contains a large amount of chloride ions, and the rainwater, salt and grease entering the concrete pores will cause great damage to the concrete or cement surface.
1】 Penetration of chloride ions: at the same time of water penetration, neutralization is caused by the penetration of carbonate gas and chloride ions.
2】 Corrosion of reinforcement: due to the water vapor, chloride ion, etc., the reinforcement is corroded. Even if it is not neutralized, the phosphorus content on the surface of the reinforcement will corrode.
3】 Crack generation: due to the corrosion of the reinforcement, the volume expansion is 2.5 times, which will cause the concrete to age and crack.
4】 Strength reduction: corrosive substances enter from the crack to accelerate the corrosion of the reinforcement, and the volume expansion reduces the strength of the concrete.
Permeable waterproofing agent is a special curing agent for road and bridge deck. Different from other pavement maintenance products, it is a product specially designed by the company for asphalt base surface. In view of the short effectiveness of asphalt surface in the early stage, it is an inorganic permeable water-based product rich in active ingredients. Compared with asphalt base surface products, it has better fluidity, dispersive moisture absorption, penetration, and environmental protection. It is the only environmental friendly water-based product in the waterproof industry. It is a high-tech new product for early preventive maintenance of expressway asphalt pavement, which undoubtedly promotes the stability during construction and further enhances the anti-corrosion protection of asphalt concrete structure
Goodcrete waterproof agent has the following functions in drinking water engineering and drainage:
▪ It has excellent waterproof and anti-corrosion protection functions, especially strong acid resistance, alkali resistance, corrosion resistance and weather resistance.
▪ Long term waterproof and anti-corrosion, the protective layer has the same life as the concrete, and there is no shelf life, because it is inorganic.
▪ The integral waterproof function of concrete building is not separated from the concrete structure, and it is a deep penetration type.
▪ In terms of no leveling layer and protective layer during construction, the construction is more convenient, saving a lot of costs and human resources, and fully meeting the requirements of Party A
The urgent need for workers;
▪ The environmental protection type conforms to GB5749-2006, which is non-toxic and environmental protection, and more conforms to the requirements of drinking water tank and drainage design.
Impermeability characteristics of permeable crystalline waterproofing agent in water supply and drainage:
Since the reform and opening-up, China's industry and agriculture have developed rapidly, but it has brought negative impacts on the environment, not only bringing haze to the air, but also affecting people's daily life and drinking water safety. In recent years, the state has begun to pay attention to environmental protection issues, and has invested heavily in sewage treatment to ensure the quality of water supply. The concrete of the sewage tank is in a strong acid and alkali environment for a long time, and it is difficult to repair once it is operated. If the concrete is damaged, the pollutants in the sewage tank will permeate to the surface and then affect the underground water quality, thus causing people's water safety problems. Concrete anti-corrosion protection must be done well to avoid future problems, and concrete protection materials should be carefully selected. According to the particularity of the sewage pool environment, the selection of concrete protection materials should meet the following physical and chemical indicators, have good waterproof and impermeability, good acid and alkali resistance and other chemical substances, excellent durability and weather resistance, non-toxic and environmental protection, and can not cause any harm to the environment, This is an urgent choice of definition.
Advantages of highway and Bridge impermeability of gudun products:
As for the concrete protective agent, Qingdao Yinchuan Expressway and Shihuang expressway have been verified, which have more excellent performance. It can penetrate into the concrete and react with a large amount of free alkali ions to form a stable branch like crystal, which is firmly embedded in the concrete pores and sealed the concrete pores. It can achieve the characteristics of air permeability and water impermeability, and allow the concrete to "breathe" freely. It will expand and contract without water. The main material is inorganic, and the pH value is consistent with the concrete. It will not produce any alkaline repulsion, forming an integral waterproof protection, It has the same service life as the concrete and becomes a permanent part of the concrete. It is integrated and has a dense structure and is waterproof.
The advantages of gudun products on road and bridge high temperature resistance: the selection of waterproof materials for road and bridge foundation surface, bridge railing and pier works is worthy of attention. The bridge surface is paved with asphalt concrete, so the waterproof material must have high high temperature resistance, and should withstand 150 ° C high temperature. Its waterproof layer will not be damaged during asphalt paving, and then the waterproof layer must be rolled under high temperature to achieve impermeability, The waterproof material must have strong compatibility with concrete and asphalt concrete at the same time, so as to ensure the stability of the bridge deck structure after asphalt concrete paving and prevent the delamination of the waterproof layer. If the bridge is officially put into use, it is particularly difficult to control the permeability. Therefore, the construction quality of the waterproof layer on the bridge deck must ensure a qualified construction and must not be damaged during the construction of the bridge deck. Therefore, inorganic permeable crystalline waterproof and anti-corrosion materials shall be used as waterproof materials for road and bridge works. This material belongs to condensation reaction, not reversible reaction, and is a natural mineral. Generally, it will not produce any reaction under the heat of 800 ℃, so it can withstand the high temperature of asphalt concrete paving. According to dbj01-54-2001 standard.
Advantages of gudun products on road and Bridge cohesiveness: the application of gudun products on the road and bridge surface is indispensable for the integral waterproofing of bridges today. It effectively penetrates into the concrete and reacts with calcium and magnesium, fills the capillary pores in the concrete to form a solid, and compacts the concrete structure to achieve waterproof effect, anti-corrosion, anti weathering and anti carbonation. This can ensure that the durability of the bridge will be affected by the alkali aggregate reaction and freeze-thaw damage of the concrete in the long-term use process. It reduces the sanding and pulverization of the concrete surface, makes the concrete surface clean and dry, improves the adhesive force between the concrete and asphalt, and also solves the delamination and easy damage of the traditional bridge deck waterproof materials, effectively avoids the damage caused by the direct contact between the external water or chemical substances and the concrete structure, and effectively protects the concrete structure.
The advantages of gudun products on road and bridge resistance to chloride ions: the scientific function of using gudun products on bridges in the marine environment to ensure that the bridge concrete is not easy to deteriorate and prolong the concrete life has recently been verified in the test center. It has changed people's misconception that as long as high-quality and high-grade concrete is used, the quality and safety requirements of marine environment bridges can be ensured. This test proves that the bridge concrete in the marine environment starts to change or deteriorate after three years without any effective protective materials. Its metamorphism is mainly caused by the intrusion of halogens chloride and sulfide from the sea; At the same time, it is also damaged by modern industrial emissions and marine floating objects. As is known to all, the sulfide of marine pollution will cause softening and delamination of concrete surface, make the reinforcement exposed and rusty, and cause the compressive strength of concrete to be seriously reduced. The penetration of chloride into reinforced concrete is formed through the thermal expansion and cold contraction of reinforced concrete, which will promote the reinforcement to become ferric chloride and accelerate the corrosion of all reinforcement. Therefore, it is an essential work to protect the reinforced concrete bridge. Its function is to prevent the intrusion of chloride and sulfide and ensure the long-term reliability and durability of the bridge. According to dbj01-54-2001 standard.
The advantages of gudun products on road and Bridge compressive strength: because the water-based permeable crystalline materials penetrate into the concrete through water and water as the carrier and react with free alkali to generate silica sol, which is firmly embedded in the air raid of concrete structure, forming an inseparable shielding layer, which enhances the surface hardness of concrete. Moreover, the silicon crystal itself is hard and plays a strengthening role on the concrete structure, generally improving the surface strength by 20% - 30%, According to ASTM standards.
Characteristics of water absorption and hydrophilic road and bridge integral waterproofing
·It is a crystalline waterproof inorganic material that penetrates deep into the concrete and has the same life as the building for a long time.
·It has a wide range of applications and can be applied to various parts of roads and bridges, such as road sills, guardrails, piers and subgrade surfaces.
·The construction method is simple and convenient. It can be sprayed twice with an interval of 16 hours. There is no need for leveling layer and protective layer.
·During the construction, the overall spraying is OK, and the low-pressure spray device does not have the problem of overlapping edge and closing.
The product is non-toxic, tasteless, non combustible and water-based environmental protection material. |
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