In the design of mixing ratio, the water cement ratio should be reduced as far as possible to reduce the amount of cement and save costs. In order to achieve the required slump, water reducer can be added.
Sand rate: sand rate is too large, will lead to the decrease of concrete fluidity, slump; If the sand rate is too small, the cohesion and water retention of concrete will deteriorate, and it is easy to produce water leakage, segregation and slurry flow. In the mix design should choose a can fill the stone gap and have a certain amount of surplus sand rate.
Aggregate: the choice of aggregate has a great influence on the workability of concrete. Under the condition that the aggregate amount is unchanged, the workability of concrete mixed with pebbles and river sand is better, while the workability of concrete mixed with gravel and machine-made sand is relatively poor. If the fineness modulus of aggregate is too large or too small, the fluidity of concrete mixture will become worse. In the mixing ratio design, if the fineness modulus is large and the fluidity is poor, the sand rate can be appropriately increased or the amount of cement can be increased to improve the workability. If the fineness modulus is too small, the sand rate can be reduced and the water consumption can be increased.
Admixture: admixture fly ash, mineral powder and so on can replace part of cement, on the one hand can reduce the amount of cement, reduce the cost, on the other hand can improve the workability of concrete. For large volume concrete, high temperature construction concrete, can be mixed fly ash, mineral powder and other admixture, adjust the workability of concrete.
Admixture: admixture can improve the workability of concrete, such as water reducing agent can not reduce the mixing water consumption under the premise, significantly improve the mixing fluidity, adding water reducing agent, concrete fluidity is greater; Pumping agent can be used to improve the pumping performance of concrete.
