Additives are increasingly common use, is the construction engineering structure and technology development of the objective requirements. In recent years, there are many large, thin-walled and new structural systems in the concrete structure, such as large volume concrete, concrete construction, vacuum water absorbing concrete, sliding mode construction and so on. The new construction technology, which is used to improve the quality of concrete, improve the engineering quality, reduce the cost and promote the new technology.
The performance of concrete is determined by the proportion of cement, sand, gravel and water. In order to improve the performance of concrete, the proportion of raw materials can be adjusted. But this tends to cause the loss of the other side. For example, in order to increase the flow of concrete, can increase the amount of water, but this will reduce the strength of concrete. In order to improve the early strength of concrete, it can increase the amount of cement, but in addition to increase the cost, it may increase the shrinkage and creep of concrete. And the use of admixture, can avoid the above shortcomings, in addition to some of the performance of the concrete, the use of concrete admixture, can greatly improve the performance of concrete. For example, as long as in concrete incorporation of 0.2% ~ 0.3% woody calcium lignosulfonate water reducing agent, without any increase in the amount of water can improve concrete slump degree one times above; as long as in concrete mixed with 2% ~ 4% sodium sulfate calcium sugar (NC) compound, in does not increase the cement quantity, can improve the strength of concrete at early age 60% ~ 70%, can also increase the later strength of the concrete.
