Magnesian expanding agent shrinkage-compensating concrete and preparation method thereof

Abstract

The invention discloses magnesium expanding agent shrinkage-compensating concrete and a preparation method thereof. The concrete is prepared from the following raw materials in parts by weight: 210 to 230 parts of cement, 100 to 130 parts of magnesium shrinkage-compensating agent, 1800 to 2200 parts of aggregate and 120 to 150 parts of water, the magnesium shrinkage compensating agent is composed of fly ash, magnesium oxide and a water reducing agent, and the aggregate is composed of siliceous rock artificial sand and dolomite macadam. According to the invention, the magnesium shrinkage-compensating agent is adopted to replace a part of a cementing material to mix the concrete, and the magnesium shrinkage-compensating agent is added to inhibit the cracking of the concrete, improve the durability of the concrete and solve the problem of dam cracking; the limit mixing amount of MgO can be increased by externally mixing the fly ash and the water reducing agent, and the expansion amount is controlled by continuously adjusting the mixing amount of MgO, so that the optimal expansion effect is achieved, and the mechanical performance, the construction performance and the like of the concrete are improved.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to a magnesium expansion agent shrinkage-compensating concrete and a preparation method thereof. Background technique [0002] Shrinkage-compensated concrete is used in mass concrete projects to compensate for the shrinkage caused by temperature drop through the expansion of the expansive agent. Compared with traditional expansion agents, magnesium expansion agents require less water, have better expansion effects, and can better compensate for the shrinkage of concrete and prevent cracks in the dam. The method is both economical and effective, and plays an important role in temperature and stress compensation of mass concrete, concrete construction technology and crack control in underground engineering. [0003] For practical projects such as dam construction, the factor of magnesium expansion agent dosage is particularly important. Because concrete contains a certain...

AI Technical Summary

Problems solved by technology

If the MgO content is too high, the cement will have problems such as poor volume stability; if the MgO content is too small, it is far from meeting the expansion required for construction, and the concrete is prone to cracking and other problems.

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