Concrete additives are abbreviated as admixtures, which are substances used to improve the performance of concrete.
According to the main functions, it is divided into four categories:
(1) Additives to improve concrete mixing and workability, including various water reducing agents, air-entraining agents and pumping agents, etc.;
(2) Additives for adjusting the setting time and hardening performance of concrete, including retarders, early strength agents and accelerators, etc.;
(3) Additives to improve the durability of concrete, including air-entraining agents, waterproofing agents and rust inhibitors, etc.;
(4) Additives to improve other properties of concrete, including air-entraining agents, expansion agents, antifreeze agents, coloring agents, waterproofing agents and pumping agents.
Water reducing agent
Under the condition that the concrete slump is basically the same, the admixture that can greatly reduce the mixing water consumption;
Slow-setting and water-reducing agent: an admixture with both retarding and water-reducing functions;
Early strength water reducing agent: an admixture with both early strength and water reducing functions;
Air-entraining agent: an admixture that can introduce a large number of uniformly distributed, stable and closed tiny bubbles during the mixing of concrete;
Waterproofing agent: an admixture that can reduce the water permeability of concrete under hydrostatic pressure;
Rust inhibitor: an additive that can inhibit or reduce the corrosion of steel bars or other embedded metals in concrete.
Air-entraining agent: It is an admixture that forms a large number of pores in the concrete due to a chemical reaction during the preparation of the concrete and gas is released.
Expansion agent: an admixture that can produce a certain volume expansion of concrete.
Antifreeze: an admixture that can harden concrete at negative temperature and achieve sufficient antifreeze and strength within a specified time.
Coloring agent: It can prepare admixture for concrete with stable color.
Accelerating agent: an admixture that can quickly set and harden concrete.
Pumping agent: an admixture that can improve the pumping performance of concrete mixtures.
The materials used to make pumping agents include superplasticizers, retarders, air-entraining agents and thickeners