| Selection and application of waterproof materials for road and bridge decks |
1】 Waterproof and impermeability 2] Acid and alkali resistance 3] Compressive strength 4] High temperature resistance 5] Adhesive properties 6] Frost and thaw resistance
Common diseases in national highway and bridge engineering: With the increasing development of highways and high-speed railways, traditional materials have caused high maintenance costs and structural damage in the past few years. However, nowadays, roads and bridges generally exhibit cracks, fractures, peeling, honeycombing, water seepage, steel leakage, and insufficient load-bearing capacity. The main reasons for this are insufficient durability and poor performance of the materials. As is well known, steel bars play a role in the tensile strength of structures, while concrete provides structural compressive strength and protection for steel bars. During the use of concrete, it undergoes environmental physical, chemical, and biological reactions, causing the internal components of concrete to undergo reaction denaturation, dissolution and precipitation, crystal expansion, and structural cracking. This not only reduces the performance of concrete, but also accelerates the damage of steel bars in concrete, leading to structural collapse.
Requirements for waterproof materials on highways and bridges:
1】 Impermeability performance: The structure and natural environment of concrete itself determine that the internal voids of concrete can cause water, acid, and alkaline pollutants to seep into the interior of concrete, leading to phenomena such as steel corrosion and concrete cracking. In order to prevent pollutant erosion, waterproof materials must have good impermeability function.
2】 Chloride ion resistance: Chloride salt damage to concrete is the main product, and the environment includes seawater, sea breeze, snow melting agents, etc. Once infiltrated, calcium chloride and crystal water are generated, causing volume expansion and corrosion of steel bars, which can cause concrete cracking. Therefore, it is necessary to choose good materials that are resistant to chloride ions.
3】 Compressive strength: High speed road surfaces bear the load of motion, asphalt paving, temperature differences, and internal and external tensile stresses. Therefore, durability materials that enhance the compressive strength of the road surface and improve the service life of concrete are selected.
4】 High temperature resistant type: The road surface is paved with asphalt, which can reach up to 150 degrees Celsius. In addition, there is friction from vehicle movement, summer exposure, and high surface temperatures. To ensure the durability of the material, high temperature resistant materials must be selected.
5】 Adhesive performance: The road surface is multi-layered, and the waterproof layer should play a role in connecting the layers and evenly transmitting the upper heavy pressure, ensuring that the overall load-bearing capacity of the structure will not be damaged by the waterproof layer, and there will be no layering between the asphalt layer and the structural layer. Therefore, selective materials must have good adhesive performance. Concrete permanent setting liquid DPS: Through infiltration, it drives a series of physical and chemical chain reactions to generate a water-based inorganic permeable protective layer that integrates crack resistance, impermeability, reinforcement, wear resistance, and self-healing of 0.3mm cracks. It can be used not only for the upstream surface but also for the downstream surface for crystal waterproofing protection. It is a new high-tech waterproof material that cannot be compared to other materials
Application of Goodconcrete Permeation Crystallization DPS in Road and Bridge Foundation and Deck
Gu Dun Architect analyzes the importance of concrete anti-corrosion:
Concrete carbonation is the chemical corrosion that concrete undergoes. Carbon dioxide in the air enters the interior of concrete and reacts with alkaline substances to produce carbonates and water, reducing the alkalinity and making it neutral. Cement produces a large amount of calcium hydroxide during the hydration process and fills the capillary pores of concrete. Its alkaline medium has a protective effect on the steel bars, causing Fe2O3 and Fe3O4 to form a passive film on the surface of the steel bars, which reduces the alkalinity of the concrete after carbonation. When carbonation exceeds the protective layer of concrete and under water and air conditions, the steel bars inside the concrete will not be protected, and the steel bars will begin to rust. It can be seen that carbonation will not directly affect the performance reduction and has no effect on plain concrete. However, it has a large side effect on reinforced concrete, reducing alkalinity and enhancing the number of hydrogen ions in the pore solution, Concrete cannot protect steel bars, especially at the seaside where the air contains a large amount of chloride ions, and rainwater, salt, and grease entering the pores of concrete can cause significant damage to the surface of concrete or cement.
1】 Infiltration of chloride ions: Neutralization is caused by the permeation of carbonate gas and chloride ions while water permeates.
2】 Corrosion of steel bars: Due to the infiltration of water vapor, chloride ions, etc., steel bars are corroded. Even if they are not neutralized, the surface of steel bars containing phosphorus will also corrode.
3】 The generation of cracks: Due to the corrosion of steel bars, the volume expands by 2.5 times, which can cause concrete aging and cracking.
4】 Strength reduction: Corrosive substances enter from cracks and accelerate the corrosion of steel bars, causing volume expansion and thus reducing the strength of concrete.
Penetrating waterproofing agent for road and bridge deck maintenance: Different from other road maintenance products, it is a product specially designed by our company for asphalt base surface. In response to the problem of short early effectiveness of asphalt surface, it is an inorganic permeable water-based product rich in active ingredients. Compared with asphalt base surface products, it has better fluidity, dispersion and moisture absorption, permeability, and environmentally friendly and harmless effects. It is currently the only environmentally friendly water-based product in the waterproofing industry. It is a new type of high-tech product for early preventive maintenance of asphalt pavement on highways, which undoubtedly promotes stability during construction and enhances the anti-corrosion protection of asphalt concrete structures
Goodconcrete waterproofing agent has the following functions in drinking water engineering and drainage:
▪ It has excellent waterproof and anti-corrosion protection functions, especially good resistance to strong acids, alkalis, corrosion, and weather.
▪ Long term waterproofing and anti-corrosion, the protective layer has the same lifespan as concrete, and there is no shelf life because it is an inorganic substance.
▪ The overall waterproof function of concrete buildings, without any layering or detachment from the concrete structure, is a deep penetration type.
▪ In terms of no need for leveling or protective layers during the construction process, the construction is more convenient, saving a lot of costs and human resources, fully meeting the requirements of the first party
Urgent needs of workers;
▪ The environmentally friendly type complies with GB5749-2006 and is non-toxic and more in line with the design requirements of drinking water tanks and drainage systems.
The anti-seepage 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 causing haze in the air, but even affecting people's daily drinking water safety. In recent years, the country 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 in the sewage tank is exposed to strong acid and alkali environments for a long time, and once it is put into operation, it is difficult to repair. If the concrete is damaged, the pollutants in the sewage tank will penetrate to the surface and affect the groundwater quality, leading to water safety issues for people. Concrete anti-corrosion protection work must be done well to avoid future problems, and the selection of concrete protective materials should be cautious. According to the special characteristics of the sewage tank environment, the selection of concrete protective materials should meet the following physical and chemical indicators, have good waterproof and anti-seepage performance, good acid and alkali resistance, excellent durability and weather resistance, non-toxic and environmentally friendly, and should not cause any harm to the environment. This is an urgent definition choice.
Advantages of the impermeability of Gudun products on highways and bridges:
In terms of concrete protectants, the verification of Qingyin Expressway and Shihuang Expressway bridges further demonstrates their extremely excellent performance. It can penetrate into the interior of the concrete and undergo chemical reactions with a large number of free alkali ions, forming stable dendritic crystals firmly embedded in the concrete capillary pores, sealing the capillary pores of the concrete, and achieving the characteristics of breathability and impermeability, allowing the concrete to freely "breathe", expand when in contact with water, and shrink without water. The main inorganic material has a pH value consistent with the concrete, and will not produce any alkaline repulsion, forming a comprehensive waterproof protection, and can have the same service life as the concrete, becoming a permanent part of the concrete, integrated and compact structure waterproof.
The advantages of Gudun products in high temperature resistance for road and bridge: The selection of waterproof materials for road and bridge base, bridge railings, and bridge piers is worth paying attention to. The bridge surface layer is paved with asphalt concrete, so the waterproof material must have high temperature resistance performance. It should withstand a high temperature of 150 degrees, and the waterproof layer should not be damaged during asphalt paving. Then, the waterproof layer must be rolled under high temperature to achieve impermeability. The waterproof material must have strong compatibility with both concrete and asphalt concrete to ensure the stability of the bridge deck structure after asphalt concrete paving and prevent the waterproof layer from delamination. If the bridge is officially used, the difficulty of permeability treatment is particularly high. Therefore, the construction quality of the bridge deck waterproof layer must ensure a qualified construction and must not be damaged during the bridge deck construction process. Therefore, the waterproof material for road and bridge engineering should use inorganic permeable crystalline waterproof and anti-corrosion materials. This material belongs to condensation reaction, not reversible reaction, and is a natural mineral. It usually does not produce any reaction under high temperature of 800 degrees, so it can withstand high temperature asphalt concrete paving. According to the DBJ01-54-2001 standard.
Advantages of Gudun products in road and bridge adhesion: Its application on road and bridge surfaces is essential for the overall waterproofing of bridges today. It effectively penetrates into the interior of concrete and reacts chemically with calcium and magnesium, filling the capillary pores inside the concrete to form a solid, compacting the concrete structure to achieve waterproofing, anti-corrosion, weathering resistance, and carbonation resistance. This can ensure that the durability of the bridge is affected by the alkali aggregate reaction and freeze-thaw damage of the concrete during long-term use. Reducing the desertification and pulverization of the concrete surface, making it clean and dry, and improving the adhesion between concrete and asphalt. It also solves the problem of layering and easy damage in traditional bridge deck waterproof materials, effectively avoiding damage caused by direct contact between external water or chemicals and the concrete structure, and effectively protecting the concrete structure.
The advantage of Gudun products in terms of chloride ion resistance for roads and bridges: for use in marine environments, the scientific function of ensuring that bridge concrete is not easily deteriorated and extending concrete life has recently been confirmed through testing at the experimental center. It has changed people's misconception that using high-quality, high-grade concrete can ensure the quality and safety requirements of marine environment bridges. This test proves that bridge concrete in marine environments begins to mutate or deteriorate after three years without the use of any effective protective materials. The main cause of its metamorphism comes from the invasion of halogen elements - chlorides and sulfides - from the ocean; At the same time, it is also affected by modern industrial emissions and marine floating debris. As is well known, sulfides from marine pollution can cause softening and delamination of concrete surfaces, exposing and rusting steel bars, resulting in a severe decrease in the compressive strength of concrete. The infiltration of chlorides into reinforced concrete is formed through the thermal expansion and contraction movement of reinforced concrete, which can promote the transformation of steel bars into ferric chloride and accelerate the corrosion of all steel bars. Therefore, protecting reinforced concrete bridges is an essential task, which prevents the invasion of chlorides and sulfides, ensuring the long-term reliability and durability of the bridge. According to the DBJ01-54-2001 standard.
Advantages of Gudun products in road and bridge compressive strength: Due to the fact that water-based permeable crystalline materials penetrate into the interior of concrete through water as a carrier and undergo chemical reactions with free alkali to generate silica sol, they are firmly embedded in the concrete structure during air strikes, forming an inseparable shielding layer and enhancing the surface hardness of concrete. In addition, the hard texture of silica crystals themselves strengthens the concrete structure, generally increasing the surface strength by 20% -30%, according to ASTM standards.
Characteristics of overall waterproofing of roads and bridges with water absorption and hydrophilicity
·Inorganic materials that deeply penetrate into the interior of concrete for crystalline waterproofing, with a long-term lifespan equivalent to that of buildings.
·Widely applicable, it can be applied to various parts of roads and bridges, such as foundation stones, guardrails, bridge piers, and base surfaces.
·The construction method is simple, just spray twice, and spray twice after a 16 hour interval, without the need for leveling layers or protective layers.
·The overall spraying is OK during the construction. The low-pressure spray does not have overlapping edges and closing problems during the construction.
The product is non-toxic, odorless, non flammable, and water-based environmentally friendly material.
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