Chemical Concrete Admixtures

Commonly used high-performance concrete admixtures - superplasticizers. Introduced in the concrete, they significantly alter the mechanical, physical and chemical properties of the mixture, the hardened concrete strength increases by 20% and in some cases - 1 5 - 2 times. The most frequent use was superplasticizer C-3. He is persistent and the preservation of the workability of the product mix within 40 - 60 minutes after injection of additives. Superplasticizer C-3 is issued in accordance with TU 6-14-625-80 in the form of an aqueous solution of 33 - 38% concentration and can be used for concrete for various purposes. Superplasticizer C-3 is recommended primarily for get moving and high-mobility concrete mixes, stacked in gustoarmirovannye prefabricated and monolithic reinforced concrete structures, to reduce the heat and humidity regimes processing and high- concrete (grades 600 and above), prepared by conventional cements. Superplasticizer C-3 is added to concrete in an amount of 0, 2 and 1, 5% by weight of cement on a dry basis. The optimal value additions are within 0 5 - 0, 8%.

At choice of concrete with superplasticizer to reduce the possible water separation should increase the proportion of sand in a mixture of aggregates. In the case of superplasticizer for making cast concrete mixes simultaneously with superplasticizer in concrete mix is recommended to introduce finely mineral powder, bentonite clay, silica and other types of additives that reduce water separation of the mixture. Dlyauvelicheniya vodonepronitsaimosti, frost and more concrete use other supplements. These include the superplasticizer 3.10. It is made of melamine. Feedstock plasticizer extremely scarce, because of that he has not found widespread use in the construction environment.