Views: 24 Author: Maia Publish Time: 2021-12-13 Origin: Site
Concrete admixture is mixed in the process of mixing concrete, to improve the performance of concrete material. The dosage is not more than 5% of cement quality.
As we all konw, there have kinds of concrete admixtures types in the world, the main functions fall into four categories:
(1) Admixtures to improve the workability of concrete mixtures, including various water reducing agents, air entraining agents and pumping agents, etc.
(2) adjust concrete setting time, hardening performance admixture, including retarder, early strength agent and accelerating agent;
(3) improve the durability of concrete additives, including air entrainment agent, waterproof agent and rust inhibitor;
(4) improve the other performance of concrete admixtures, including aerating agent, expansion agent, antifreeze, colorant, waterproof agent and pumping agent.
High efficiency water reducing agent (also known as superplasticizer) refers to the admixture which can greatly reduce the water consumption under the condition of keeping the slump of concrete basically the same.
Type and characteristics of new high-efficiency water reducing agent at present, international and domestic preparation of high strength, high-performance concrete, are using high-efficiency water reducing agent, this high-efficiency water reducing agent can be divided into 4 categories: A, Naphthalin department (Naphthalin); B, poly-carboxylic acid; C, Melamine; D, AminosuHonic acid.
High efficiency water reducing agent (LS -- AS) has the excellent performance of low dosage and high water reducing rate. With the increase of dosage, the water reducing rate increases greatly, but there is a saturation point, and the slump and fluidity retention are good after reaching this point. Beyond the saturation point, the increase of water reduction rate slows down rapidly and has obvious retardation.