Concrete mixture for PHC (Prestressed High-strength Concrete) pipe pile and PHC pipe pile prepared therefrom

Abstract

The invention discloses a concrete mixture for a PHC (Prestressed High-strength Concrete) pipe pile. The concrete mixture comprises the following raw materials: 400-520kg / m<3> of cementing material, 120-145kg / m<3> of water, 675-870kg / m<3> of sand, 1050-1110kg / m<3> of gravel and a polycarboxylate water reducing agent, wherein the usage amount of the polycarboxylate water reducing agent by mass is 1.0-1.5% the mass of the cementing material, and the cementing material is prepared from the following ingredients in percentage by mass: 80-95% of cement and 5-20% of mineral admixture. According to the concrete mixture, after centrifugal molding, the concrete mixture can be over 80MPa only through normal-pressure steam curing and short-time natural curing and can be over 85 MPa through 28-day natural curing, a high-pressure steam curing process is not needed, the production cycle is shortened, and approximately 70% of the consumption of standard combustion coal for the production of every one meter of the pipe pile can be reduced.

Description

technical field [0001] The invention relates to a PHC pipe pile concrete mixture and a PHC pipe pile prepared therefrom, in particular to a concrete mixture for preparing a PHC pipe pile by adopting pumping distribution and pressure-free curing and a PHC pipe pile prepared therefrom. pipe pile. Background technique [0002] With the rapid expansion of cities and the large-scale development of infrastructure construction such as high-speed railways, expressways, port terminals, and cross-sea bridges, there is a huge demand for PHC (high-strength prestressed) pipe piles. According to reports, in 2011, my country's PHC pipe piles The output reached 350 million meters. Existing PHC pipe piles are mostly produced by mold opening method and manually operated fabric distribution process. This process has the following defects: (1) The labor intensity of the workers is high, the workshop temperature is high, the noise is large, and the working environment is poor; (2) The degree of ...

AI Technical Summary

Problems solved by technology

Existing PHC pipe piles are mostly produced by mold opening method and manually operated fabric distribution process. This process has the following defects: (1) The labor intensity of the workers is high, the workshop temperature is high, the noise is large, and the working environment is poor; (2) The degree of automation Low, large quality fluctuations; (3) Large material loss

The existing pipe pile maintenance process will bring the following insurmountable problems: (1) Large energy consumption in the production process: the unit energy consumption of the existing PHC pipe pile production process is as high as 4kg / m, and high-pressure steam curing accounts for 70% of it (2) Insufficient durability of concrete: After high-pressure steam curing, the performance of concrete such as anti-chloride ion penetration and freeze-thaw resistance is seriously reduced. Some studies have shown that the number of freeze-thaw cycles of concrete after high-pressure steam curing is less than 100 times. The durability of the building may have adverse effects; (3) It is easy to cause environmental pollution and safety hazards: the prestressed pipe piles produced by the existing technology will produce a large amount of slurry, and the steam production process will generate a large amount of greenhouse gases, which is easy to cause Environmental pollution, and there are certain safety hazards in the autoclave

Chinese patents 2008100218824 and 2008100218824.X respectively disclose a superplasticizer for the production of PHC pipe piles and its application in the production of prestressed pipe piles. The main technical route is to use polycarboxylate water reducer and a large amount of Inorganic salt accelerator (such as nitrite, thiocyanate, sulfate, thiosulfate, etc.) Its essence is also to promote the development of concrete strength through inorganic salts, which is detrimental to the durability of concrete

In addition, the production of PHC pipe piles by the above method is still difficult to realize the fluidization of pipe pile concrete, and it is still produced by conventional mold opening technology, which fails to solve the problems of low degree of automation and high labor intensity of workers

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