Multi-scale polypropylene fiber pumping concrete

Abstract

The invention relates to multi-scale polypropylene fiber pump concrete which is prepared from the following raw materials: cement, mineral powder, fly ash, sand, coarse aggregate, a water reducing agent, a preservative, polypropylene fibers and water. Through a large number of experiments, the appropriate proportion of all the components is optimized, and the concrete with high strength and good pumping performance is provided. The polypropylene fiber pump concrete disclosed by the invention has excellent slump, expansion, compressive strength, splitting tensile strength and early-stage crack resistance; and has good workability and good pumping performance, and can be used for on-site construction pumping.

Description

technical field [0001] The invention belongs to the technical field of concrete building materials, and in particular relates to a multi-scale polypropylene fiber pumped concrete. Background technique [0002] Pumped concrete is a kind of ready-mixed concrete that is poured with a concrete pump. Compared with ordinary concrete, pumped concrete speeds up the construction progress, saves labor and reduces the intensity of manual work, especially in more and more In the cast-in-place structure of high-rise buildings, a large amount of concrete needs to be transported horizontally and vertically to very high construction points. Moreover, the use of pumped concrete can also improve the construction quality, significantly reduce the construction cost, and obtain significant technical and economic benefits in the project, so the pumped concrete technology has been widely used. At present, pumped concrete has become the most widely used variety in ready-mixed concrete. [0003] T...

AI Technical Summary

Problems solved by technology

[0003] The performance requirements of pumped concrete are higher than those of ordinary concrete, and the slump is larger than that of ordinary concrete. At the same time, its fluidity during transportation in the mixer truck must be guaranteed. If there is a problem with the performance, it will occur on site due to poor fluidity. The problem of not pouring

At present, there are still a series of problems in pumping concrete that need to be solved urgently: (1) The suspension state of the stones in the cement is lost, they accumulate together, and then block the pipeline; (2) The concrete itself slumps due to the unreasonable design of the mix ratio (3) As the pumping speed increases, the pump pressure loss increases

(4) Its mechanical properties are not enough, the compressive strength and splitting tensile strength are not up to the standard, and the crack resistance is poor, which will lead to various diseases of the tunnel lining, such as lining cracking, lining corrosion, water leakage, etc., which are serious Affect the driving safety; and for the serious disease section, it is necessary to carry out disease treatment, the replacement of the second lining and even the replacement of the arch wall, resulting in huge economic losses

(5) Pumping fiber concrete is easy to agglomerate and cause pump blockage, or easy to bleed and segregate

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