干湿循环对CA砂浆力学性能影响的试验研究

Influence of Drying and Wetting Cycles on the Mechanical Properties of CA Mortar

采用CSS8810-100KN电子万能试验机对不同干湿循环等级的CA砂浆试件进行了单轴压缩试验,获得了相关力学性能指标随干湿循环等级的变化规律。结果表明:CA砂浆具有较强的韧性,其应力-应变曲线分为初始压密、弹性变形、塑性变形和应变软化4个阶段;峰值应力、弹性模量、破坏能随干湿循环等级的增加,先增大后减小,割线模量随轴向应变的增加先增大后减小,其主要影响因素为初期干湿循环使CA砂浆中未水化水泥进一步水化,砂浆结构更加密实,后期干湿循环导致微缺陷的产生和扩展;塑性功整体随循环等级的增加逐渐减小,干湿循环损害了CA砂浆的减振性能。通过数据变换得到了CA砂浆各力学性能指标与自变量之间的函数关系,为研究成果在实际工程中的应用提供了便利。

Uniaxial compression test on CA（cement-asphalt） mortar specimens in different drying and wetting cycle levels is carried out by using CSS8810-100KN electronic universal testing machine.The variation of mechanical property indicators against drying and wetting cycle level is obtained.Results show that CA mortar has strong toughness,and it＇s stress-strain curve is divided into four phases：initial compaction,elastic deformation,plastic deformation and strain softening.Peak stress,elastic modulus and damage power first increase and then decrease with the increase of drying and wetting cycle level.Secant modulus first increases and then decreases with the increase of axial strain,because the early drying and wetting cycles further hydrate the unhydrated cement in CA mortar and densify the structure of CA mortar,and the late drying and wetting cycles give rise to the emergence and expansion of micro-defects in CA mortar.Plastic work gradually decreases with the increase of cycle level,and the cycles damage the vibration damping performance of CA mortar.Through data transformation,the functional relationship between the mechanical properties of CA mortar and the independent variables is obtained,which facilitates the application of research results to practical engineering.