Expanding agent for concrete mortar having staged expansion property and method for preparing the same

Abstract

The application relates to the technical field of building materials, in particular to an expansive agent with a staged expansion characteristic for concrete mortar and a preparation method, which comprises the following components: a delayed expansion clinker, a hard expansion trigger, an industrial solid waste-based carrier, a crack self-repair component and an ion migration regulator, the delayed expansion clinker is prepared by mixing bauxite and phosphogypsum at a ratio of 1:1, the hard expansion trigger is nanoscale magnesium oxide coated porous silicon dioxide and is prepared by a sol-gel method, the industrial solid waste-based carrier is prepared by mixing desulfurization gypsum and high-calcium fly ash at a ratio of 3:4, the crack self-repair component is methyl sodium silicate loaded zeolite molecular sieve, and the ion migration regulator is prepared by mixing azodicarbonamide and carboxymethyl cellulose at a ratio of 2:1; the expansive agent provides controllable expansion at different stages of concrete hardening, effectively compensates for shrinkage cracks, enhances structural durability, reduces costs by using industrial solid waste, and is suitable for various construction projects.

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