砂浆-骨料粘结界面力学性能

Research on Mechanical Properties of Mortar-Aggregate Bonding Interface

水泥砂浆骨料粘结界面较水泥砂浆相比,因其孔隙率较大、密度小、强度低等特点,通常被视为混凝土中的薄弱区域,因此,研究水泥砂浆骨料粘结界面的力学性能,对于掌握混凝土开裂特征以及力学性能有重大意义。通过进行三点弯曲试验和劈裂拉伸试验,获得不同配合比下水泥砂浆骨料粘结界面的断裂能和抗拉强度,建立以水灰比为变量的水泥砂浆骨料粘结界面参数计算模型。研究表明,水泥砂浆骨料粘结界面的断裂能以及抗拉强度随着水灰比的增大而逐渐减小,同时,它的界面参数还受石材种类影响。所取得成果可为增强界面的粘结强度研究,以及改善混凝土的力学性能提供参考和借鉴。

Compared with cement mortar,the cement mortar-aggregate bonding interface is usually regarded as a weak link in concrete due to its larger porosity,lower density and lower strength.Therefore,it is of great significance to study the mechanical properties of cement mortar aggregate interface for mastering the cracking characteristics and mechanical properties of concrete.In this study,the two important interface parameters,the fracture energy and tensile strength of the cement mortar-aggregate interface,were measured through indoor tests,three-point bending test and split tensile test,and finally established that the water-cement ratio is unknown.A calculation model for the parameters of the cement mortar-aggregate bonding interface.Studies have shown that the fracture energy and tensile strength of the cement mortar-aggregate bonding interface gradually decrease with the increase of the water-cement ratio.At the same time,its interface parameters are also related to the type of stone.The calculation model of bonding interface parameters established in the experiment has an important effect on enhancing the bonding strength of the interface and improving the mechanical properties of concrete.