粗骨料形状对水工混凝土强度性能影响试验研究

Experimental Study on the Influence of Coarse Aggregate Shape on Strength Properties of Hydraulic Concrete

粗骨料形状是影响混凝土强度性能的因素之一。由于精细测量粗骨料形状尺寸的工作量大且相关试验少,导致关于粗骨料形状对混凝土强度性能的影响规律存在不确定性。首先通过人工筛选将粗骨料区分为片状石与块状石,然后随机抽取粗骨料进行形状尺寸测量,接着统计分析了骨料的球度、扁平度等形状参数,进而根据筛选的骨料,设计了3种不同片状石含量的骨料组合,并针对0. 5水胶比的混凝土开展了不同龄期抗压强度和劈拉强度试验。研究表明,虽然筛选后的骨料形状尺寸具有明显的区分度,但上述3种不同骨料形状组合混凝土的抗压强度和劈拉强度相差比较小,且与上述形状参数变化关系不明显。

The shape of coarse aggregate is one of the factors that affect the strength of concrete.Due to the large amount of workloads in the fine measurement of coarse aggregate shape and size and few relevant tests,there is uncertainty about the influence of coarse aggregate shape on the strength properties of concrete.Firstly,the coarse aggregate is divided into flake stone and block stone by artificial screening,then the coarse aggregate is randomly selected for shape and size measurement and the shape parameters such as sphericity and flatness of the aggregate are statistically analyzed.According to the screened aggregate,three different aggregate combination with different flake stone contents are designed,and the compressive strength and splitting tensile strength tests of the concretes with 0.5 water-cement ratio under different ages are carried out.The results show that,although the shapes and sizes of selected aggregate have obvious differentiation,the differences between the compressive strength and splitting strength of the three kinds of concrete with different aggregate shapes in these tests are relatively smaller,and there is no obvious relationship with the change of the above shape parameters.