Low-thermal-expansion concrete and admixture

Abstract

The invention relates to a low-thermal-expansion concrete and an admixture. The concrete comprises cement clinker, fly ash, zeolite powder, granite gravel and the balance being water. The cement clinker comprises the following components in percentage by weight: 5-20% of C3S, 20-45% of C2S, 5-10% of C3A and 5-10% of C4AF, and is characterized by further comprising 20-40% of barium oxide and 5-15%of strontium oxide. The ratio of the cement clinker to (fly ash and zeolite powder) to granite gravel is 1: (1-2): (2-4), and water to cement clinker is 0.2-0.4. Barium oxide and strontium oxide are used as expansion admixtures for the first time to replace fly ash in particular zeolite powder under the assistance of a newly developed retarder; and granite gravels with different sizes are matchedto realize a low-heat micro-expansion effect of concrete.

Description

technical field [0001] The application relates to the field of construction engineering, in particular to cement / concrete (concrete), in particular to a low-heat micro-expansion concrete. Background technique [0002] Cement concrete is by far the largest man-made material in the world, and this situation will continue for a long time in the future. Concrete has two inherent material characteristics, one is the volume deformation-shrinkage accompanied by strength growth during the hydration hardening process, and the other is the low tensile-compressive strength ratio of concrete materials. Concrete fractures (cracks) when the tensile stress inside the concrete caused by shrinkage exceeds the tensile strength of the concrete. It is generally considered that cracks are the biggest defect of concrete structures, which will lead to the intrusion of harmful media such as moisture, CO2, Cl-, etc., accelerate the corrosion of steel bars and reduce durability, and cause the reduct...

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Problems solved by technology

[0014] Based on the researches on expansion and low-heat cement concrete in the above-mentioned theoretical and engineering circles, there is still the problem of insufficient compensation in the early and mid-term, especially in the early stage, resulting in concrete cracking

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