不同强度海水珊瑚骨料混凝土断裂性能对比研究

对不同强度海水珊瑚骨料混凝土(SCAC)开展了抗压、劈裂拉伸以及预切口梁三点弯曲试验,获得了其荷载-裂纹口张开宽度关系以及断裂能、特征长度等断裂参数.结果 表明:随着SCAC强度等级的提高,其抗压强度及劈裂抗拉强度增大,拉压强度比小幅降低,开裂荷载与峰值荷载比明显增大,峰值裂纹口张开宽度显著降低;SCAC试件破坏均为裂纹贯穿骨料,断面光滑;提高SCAC强度等级可在一定程度上弥补珊瑚骨料的低强度缺陷,提高SCAC的断裂性能,但其脆性也相应增加.

Comparative Study on Fracture Properties of Seawater Coral Aggregate Concrete with Different Strengths

Compressive test, splitting tensile test and three point bending test on pre notched beams were carried out for seawater coral aggregate concrete(SCAC) with different strength grades. The fracture parameters such as load crack width relationship, fracture energy and characteristic length were derived. The results show that as the strength grade of SCAC increases, its compressive strength and splitting tensile strength increase, the ratio of tensile compressive strength decreases slightly, the ratio of cracking load to peak load increases significantly, whereas the peak crack mouth opening displacement decreases. It is noted that the cracks of SCAC tend to propagate across the aggregates, thus yielding smooth crack surface. Increasing the strength grade of SCAC can somewhat compensate the low strength features of coral aggregates, resulting in increased fracture energy, but the brittleness raises accordingly.