1. Introduction: The concrete of the harbour wave splash area reinforced concrete buildings, hydropower stations with large temperature difference, industrial plants, railway bridges and culverts, concrete pavements, bridges and municipal engineering are subject to salt spray, rainwater, ultraviolet rays and water vapor penetration. , Corrosion, hollowing and other phenomena have not reached the original design performance. In order to ensure the normal use of these buildings, various departments have to invest huge sums of money in maintenance every year. Experts estimate that the annual maintenance cost may be hundreds of billions of yuan
Second, the reason for the corrosion of concrete structure:
Because the concrete has defects such as pores and bubbles in it, it has certain permeability. Acidic gases such as CO 2 and SO 2 in the air are neutralized with Ca(OH) 2 in the liquid phase of concrete to neutralize the concrete. The direct consequence of the decrease in alkalinity of concrete after carbonization is that the passive film on the surface of the steel bar loses its stability and is destroyed, and the concrete cannot protect the steel bar from corrosion. Chloride ion penetration is extremely strong, can penetrate into the interior of the concrete, reach the surface of the steel bar, quickly destroy the passivation layer on the surface of the steel bar, cause corrosion of the concrete, and form corrosion spots. When the stress is uneven, the stress concentration causes the steel bar to break, which affects the durability of the concrete.
3. The protection mechanism of KH-559D anticorrosive impregnating agent:
Concrete impregnation is through the KH-559D, which has a small molecular structure and strong water-repellent groups, quickly penetrates into the concrete and chemically reacts with the hydrated cement, thereby forming a strong water-repellent barrier on the capillary pore wall. Improve the waterproofness and comprehensive performance of concrete products. Especially compared with other materials, this kind of protective agent is more effective and durable in preventing the penetration of water and chloride on high-grade concrete with low porosity and bridges with extremely bad surrounding environment. The reaction mechanism is as follows: under the alkaline catalysis of water and concrete, the ethoxy group in the KH-559D molecule first undergoes a hydrolysis reaction to form silicon hydroxyl groups, and then between the silicon hydroxyl groups, the silicon hydroxyl groups and the hydroxyl groups in the concrete surface and capillary channels A further condensation reaction takes place to form a network-like silicone resin. The silicone molecules are firmly attached to the surface of the concrete and the capillary channels through stable silicon oxide bonds.
Physical indicators
| Appearance: | colorless transparent liquid |
| Density (ρ20, g / cm3): | 0.874-0.877 |
| Diopter (n25D): | 1.416 |
Fourth, product performance
(1) The average value of water absorption should not be greater than 0.01MM/MIN1/2
(2) Strong permeability, for concrete with a strength level not greater than C45, the depth of KH-559D should reach about 4-5MM; for strength greater than For concrete equal to C45, the impregnation depth should reach 3-4MM.
(3) The average value of the reduction effect of chloride absorption is not less than 90%.
(4) KH-559D does not change the original appearance of the building after construction, suitable for building appearance Projects with special needs, such as clear water concrete engineering, etc.;
(5) Excellent alkali resistance and durability, protection life of more than 20 years;
(6) Can effectively inhibit the concrete structure caused by environmental corrosion such as acid rain and mold moss The surface of the structure is dark and moldy, which can maintain the long-term appearance of the concrete structure;
5. Application effect diagram of KH-559D anticorrosive impregnating agent
6. Construction methods:
1. Used as a building waterproofing agent and protective agent, can form a water-repellent layer on the surface of the substrate, effectively prevent water penetration, sunlight, acid and alkali corrosion, and extend the service life of the building.
2. Used as an inorganic filler surface treatment agent to improve the dispersion and compatibility of fillers in plastics, rubber, and resins.
3. Used as a dispersant for pigments, so that the treated pigments have better dispersibility.
VII. Construction and maintenance methods
(1) In order to ensure the effect of KH-559D impregnation treatment, the new construction should be constructed after 2-4 weeks of curing of concrete members, and the repair project should be constructed after 1-2 weeks of maintenance. When the ambient temperature is lower than 5℃, or higher than 40℃, or the wind power is higher than level 6, construction should be stopped to reduce material loss.
(2) Repair the defects of the concrete structure before construction, rinse with wire brush, compressed air and fresh water, remove the floating dust, sewage, oil and other pollutants on the surface, and keep the surface dry for more than 3 days.
(3) Before immersing KH-559D in a large area, a coating test should be carried out. The area of the test area should be 1-5 square meters, and then the core should be sampled and tested according to the specified method. When the test result meets the judgment standard In order to spray KH-559D impregnating agent on the structure in a large area.
(4) Usage and dosage of KH-559D liquid: spray twice with liquid waterproofing agent, each spraying volume is 300G/m 2 , interval time is 4-6H, in order to achieve higher penetration depth. When spraying liquid, spray continuously to make the surface to be saturated overflow. For horizontal construction, spray or brush until the surface of the substrate is moist or mirror-like. On the facade, spray from bottom to top, the vertical flow length is 15-20CM, and the surface to be coated should be kept wet for several minutes.
(5) Construction equipment: airless spraying equipment is recommended for large-area construction, which has high construction efficiency and can reduce the loss of raw materials; small areas can use brushes or scrapers; if it suddenly rains during construction, stop construction immediately and carefully cover it The components have been constructed to prevent the active components of KH-559D from being lost due to rain before curing, which will affect the construction effect.
(6) Maintenance: After construction, KH-559D should ensure that it will not be rained for at least 24 hours and naturally dried; to ensure the ideal treatment effect, the surface should be kept dry for at least 36 hours in summer and at least 72 hours in winter.
(7) The absorption process of KH-559D liquid impregnating agent will last for several hours. The absorption rate depends on the environmental conditions, such as the relative humidity of the air, the concrete mix ratio, the moisture content of the concrete, the degree of exposure of the treated surface, sunlight and wind speed, etc. Wait, the surface of the concrete may temporarily become black, and the original appearance can be restored after a few days.
8. Packing:
210L iron drum: 180kg/drum
25L drum: 20kg/drum
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