Additive for reducing drying shrinkage of concrete as well as preparation method and use method thereof

The invention relates to a concrete admixture, in particular to an admixture for reducing drying shrinkage of concrete and a preparation method and a use method thereof, and the admixture comprises the following components in percentage by mass: 40-60% of shrinkage reducing agent, 30-50% of expanding agent, 2-8% of water-retaining agent and 2-8% of internal curing agent. Compared with the prior art, the admixture disclosed by the invention is added into the cement concrete in an internal doping manner, so that the pore structure in the cement concrete can be optimized, the hydration degree of a cementing material in the cement concrete is further improved, and the drying shrinkage of the concrete in the hardening process is reduced; the concrete modifier has a certain improvement effect on the compressive strength and tensile strength of concrete, also has a good effect on improving the durability of the concrete, and can reduce the 28d drying shrinkage of the concrete by about 23-67% through measurement. 本发明