Multifunction shrinking-compensate concrete pump-feed agent

Abstract

The invention provides a multifunction compensation shrinkage concrete pumping agent, and belongs to the technical field of concrete admixture. The invention is to provide a multifunction compensation and shrinkage concrete pumping agent which can reduce cracks generated early and can reduce cement cracks which are harmful into unharmful cracks in construction when concrete batching plants produce pumping concrete. The multifunction compensation shrinkage concrete pumping agent consists of a naphthalene sulfonic acidformaldehyde condensation product water reducer, aluminum ammonium sulfate, modified lignin sulfonate, lauryl sulfate sodium salt, hydrogen peroxide, aluminum sulfate and water. After the components are mixed and beaten, the mixture is adjusted with sodium hydroxide to the extent that the pH is equal to or more than 5, thus getting aqua. The pumping agent of 1.9 to 4 percent of cement in concrete by weight is added. By adopting the pumping agent, the free expansion coefficient of the pumped concrete ranges from 0.015 to 0.025 percent during the period from initial set to final set; the trace confined expansion coefficient is 0.004 to 0.007 percent before the strength of the concrete becomes 10 MPa from the final set of concrete. Accordingly, by adopting the concrete pumping agent, the early cracks of the pumped concrete are reduced; and the width of the cracks is reduced to the extent that the cracks become unharmful, thus ensuring good economic and social benefits in respect of the quality of pumped concrete.

Description

technical field [0001] The invention relates to a multifunctional shrinkage-compensating concrete pumping agent, which belongs to the technical field of concrete admixtures. Background technique [0002] Currently. Commercial concrete (pumping) has been widely used in large and medium-sized cities in my country. However, in the application practice, it is a common problem to find early cracks in concrete. Since the pumped concrete is a concrete with low water-binder ratio and large slump, the early strength of the concrete grows relatively fast. After the concrete is poured, under the influence of the surrounding medium, the water will lose quickly and the humidity will drop, which cannot fully meet the early water needs of the cement. Therefore, the early self-shrinkage, temperature shrinkage and dry shrinkage of the pumped concrete are the main reasons for the early cracks of the pumped concrete. [0003] my country's reinforced concrete cracks allow regulations. For re...

AI Technical Summary

Problems solved by technology

Therefore, when using it, the material is often added manually on the belt conveyor that transports sand and gravel, which is not only labor-intensive, but also difficult to ensure the accuracy of the dosage, and it must be used at the same time as a water-based pumping agent, which increases the cost of pumping concrete.

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