砂率对C30～C50混凝土强度及工作性能的影响

Influence of Sand Percentage on Strength and Workability of C30-C50 Concrete

砂率是混凝土配合比设计的三个基本参数之一。确定合理的砂率可以使混凝土新拌混凝土具有很好的工作性,在搅拌、运输以及在施工过程中有良好的流动性、粘聚性、保水性。通过设计C30、C40、C50三个不同强度等级的混凝土配合比,在每组实验中,保证水灰比以及砂和石子的总量不变,调整砂率,通过砂率的变化来分别测定不同砂率下混凝土新拌混凝土的坍落度、表观密度以及强度等参数,从而比较出砂率的变化对混凝土新拌混凝土工作性能的影响规律。实验表明,C30混凝土的砂率设定在0.43左右、C40混凝土砂率设定在0.40左右、C50混凝土设定在0.37左右比较合适。

The sand ratio is better than one of the three basic parameters of the concrete mix design. To determine the reasonable sand rate can make the concrete mixture is very good, in the mixing,transportation and construction process have good cohesion,fluidity,water retention. Sand grain size,which is much smaller than the stone,has a large specific surface area,pore and filled with coarse aggregate in mixture. This topic through the three set of experiments,C30,C40,C50 three different strength grades of concrete mix proportion,in each experiment,ensure the water cement ratio and total amount of sand and stones invariant,adjust the sand ratio,were determined by variation of sand ratio to slump,apparent density and the strength parameters of different sand ratio of concrete mixture,which compare with the effect of variation of sand ratio on the performance of concrete mixture. Experiments show that,C30 concrete sand rate set at around 0. 43,C40 concrete sand rate set at around 0. 40,C50 concrete set more appropriate at around 0. 37.