Super-light aggregate concrete for long-distance homogeneous pumping construction and preparation method thereof

Abstract

The invention belongs to the technical field of concrete and in particular relates to a super-light aggregate concrete for long-distance homogeneous pumping construction, a preparation method thereof and a pumping construction process. The super-light aggregate concrete for the long-distance homogeneous pumping construction is characterized by being prepared from water, a gel material, a fine aggregate, a coarse aggregate and an additive, wherein the gel material consists of cement and fly ash; the coarse aggregate is super-light ceramic particles; the fine aggregate is ceramic sand; the additive is a pumping agent and a water reducing agent; each cubic meter of concrete comprises 180 to 250kg of water, 160 to 250kg of cement, 250 to 320kg of fly ash, 350 to 450kg of super to light ceramic particle, 300 to 400kg of ceramic sand, 3.5 to 4.5kg of water reducing agent and 0.35 to 0.45kg of pumping agent. In a pumping process, the super-light aggregate concrete prepared by the method has relatively good working performance and homogeneity. The problems of easy blockage of a pump, high slump loss, layered concrete and the like in the pumping construction process of the super-light aggregate concrete are solved.

Description

technical field [0001] The invention belongs to the technical field of concrete, and in particular relates to an ultra-light aggregate concrete used for long-distance homogeneous pumping construction, a preparation method thereof, and a pumping construction process. Background technique [0002] The emergence of lightweight aggregates solves the defects of concrete's heavy weight and low specific strength, making concrete widely used in wall insulation, high-rise buildings and bridge deck pavement. However, with the application of super high-rise (above 100m) buildings and long-span (300-500m) structures, higher requirements are placed on the self-weight and specific strength of concrete, and ordinary lightweight concrete obviously cannot meet the requirements. Therefore, scholars at home and abroad put forward the concept of ultra-light aggregate concrete again on the basis of lightweight concrete. The so-called ultra-light aggregate means that the bulk density is 200-500kg...

AI Technical Summary

Problems solved by technology

Such long-distance pumping has very strict requirements on the working performance of concrete, and ultra-light aggregates have a high water absorption rate. During pumping construction, ultra-light aggregate concrete will appear light-weight porous like aggregates, resulting in concrete breakdown. Problems such as layer segregation, large slump loss, and the fact that the aggregate absorbs moisture in the concrete under pressure will cause pump blockage, etc.

This brings huge difficulties to the construction of concrete, affects the smooth progress of the construction period, and causes huge economic losses.

Based on relevant research at home and abroad, the three main problems of pumping lightweight concrete are: (1) Reduce the working performance. When pumping, the pores in the ultra-light aggregate will form a capillary effect and absorb from the cement slurry. A large amount of free water reduces the actual water-binder ratio of the concrete, resulting in a decrease in the workability of the concrete; (2) When the water infiltrates from the cement slurry into the light aggregate, the volume of the concrete will decrease slightly. When the pump pressure is increased, the concrete in the The air is compressed into the light aggregate, which is why the pumped light aggregate concrete is compressible; (3) When the pump pressure decreases or disappears, the compressed air existing in the aggregate hole will compress the aggregate Extrusion of moisture in the hole; if this happens in the pump pipe, it will cause the concrete mixture to bleed and block the pump pipe; if the pressure release occurs at the pouring site, the extruded moisture will wrap on the surface of the light aggregate, Affect the interface between aggregate and cement stone, and destroy the bond between cement stone and aggregate, thereby affecting the performance of concrete, and even causing problems such as loss of strength and poor durability of concrete

In addition, the density of ultra-light aggregate is much lower than that of cement paste, and it will float up in concrete, causing stratification of concrete and resulting in poor homogeneity.

The problems in the construction of ultra-light aggregate concrete described above have seriously restricted the development of ultra-light aggregate concrete, and an effective solution is urgently needed

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