Microwave heating super early strength cement concrete pavement repair material and preparation method thereof

Abstract

The invention discloses a microwave heating super early strength cement concrete pavement repair material and a preparation method thereof. The repair material contains the following constituents: cement, siliceous dust, fly ash, microfine heavy calcium carbonate, high-efficiency water reducing agent, calcium oxide, calcium chloride and sodium sulfate in the weight ratio of 1 : 0.1 : 0.1 : 0.1 : 0.005 : 0.012 : 0.03 : 0.01, and water consumption is 40% of mass sum of the constituents. The preparation method comprises the following steps of: according to the proportion, adding the raw materials and the water to a cement paste mixer and mixing for 60s, and forming by using a plastic mould; covering a plastic film on the surface of the formed test piece; counting from the moment of adding water for mixing, and testing initial setting time and final setting time in microwave heating process; heating the formed test piece by microwave to 50 degrees centigrade, and stopping heating; and when the surface temperature of the test piece is reduced to 40 degrees centigrade, reheating to 50 degrees centigrade by microwave, repeating like this, and stopping and testing related performance of the test piece after two hours, wherein the test result shows that the repair material has short setting time, high early strength, strong bonding capacity and dry narrow and can meet the requirements on traffic restoring after two hours.

Description

technical field [0001] The invention relates to a patching material for cement concrete pavement, in particular to a patching material for ultra-early-strength cement concrete pavement heated by microwaves. Background technique [0002] Cement concrete pavement materials are widely used in the construction of key infrastructure such as highways and airports, among which cement concrete pavement accounts for more than 60% of the total mileage of China's highways, and airport runways are also dominated by cement concrete. Different degrees of cracking occurred due to reasons such as construction, post-maintenance and over-heavy traffic. The main reason is that the cement concrete material will shrink due to the evaporation of internal water during use, resulting in internal residual stress. Cement concrete pavement cracks; on the other hand, cement concrete pavement materials used in the field are greatly affected by natural conditions such as temperature and moisture, which a...

AI Technical Summary

Problems solved by technology

[0004] First, inorganic repair materials mainly have problems such as long open traffic time for concrete pavement projects, and a place needs to be repaired repeatedly; organic repair materials have poor compatibility with the original concrete and have strict requirements on the repair interface. Not resistant to aging, resulting in poor durability after repairing, expensive, and not conducive to environmental protection; although composite repairing materials overcome some of the shortcomings of the above two types of repairing materials to a certain extent, they still have high prices, large performance variability, and adverse effects on the use environment. Disadvantages such as poor adaptability

[0005] Second, the compatibility between repairing materials and original cement concrete pavement materials is relatively poor, and the repaired concrete and repairing materials cannot coexist closely in terms of physics and chemistry. The main reason is that various repairing materials have different chemical components. Its shrinkage performance and bonding strength are quite different, and they have different performances under different conditions, and the difference in performance often leads to damage on the contact surface, such as peeling, falling off, etc.

[0006] Third, it takes a long time for various cement concrete pavement repair materials to set and harden to produce strength, and the fastest can reach 20.0MPa after 4 to 6 hours, which seriously affects the time for the cement concrete pavement project to be open to traffic

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