动静加载下微硅粉-橡胶/水泥砂浆的力学性能

Mechanical properties of micro silicon powder-rubber/cement mortar under dynamic and static loading

为研究微硅粉(Micro silicon powder,MP)-橡胶/水泥砂浆的力学性能,试验设计了16组试件,通过单轴抗压试验与抗冲击试验(分离式霍普金森压杆(SHPB))分析不同微硅粉掺量、橡胶粒径和养护龄期试件的峰值应力、峰值应变、弹性模量、抗冲击强度、破坏形态与应力-应变曲线。单轴抗压试验表明:在相同的养护龄期下,橡胶颗粒的加入使砂浆试件的抗压强度与弹性模量降低,峰值应变增加,加入微硅粉后试件的强度与弹性模量会有所回升。抗冲击试验表明:橡胶会降低砂浆的抗冲击强度,但能改善砂浆的破坏形态,而微硅粉不仅能增强这种改善作用,还能提升橡胶/水泥砂浆的抗冲击强度,另外加入微硅粉后,试件的应力-应变曲线的峰值荷载会由于其弹性变形与弹塑性变形阶段的缩短而向左偏移,但破坏阶段明显延长。

In order to study the mechanical properties of micro silicon powder(MP)-rubber/cement mortar,16 sets of specimens were designed and analyzed by uniaxial compression test and impact test(separate Hopkinson pressure bar(SHPB))for peak stress,peak strain,modulus of elasticity,impact strength,damage morphology and stress-strain curves of the specimens with different micro silicon powder dosage,rubber particle sizes and curing ages.The uniaxial compressive test shows that the addition of rubber particles decreases the compressive strength and modulus of elasticity of mortar specimens and increases the peak strain at the same age of maintenance,and the strength and modulus of elasticity of the specimens recover after the addition of micro silica powder.The impact resistance test shows that:Rubber will reduce the impact strength of mortar,but can improve the damage morphology of mortar,and micro silica powder not only enhances this improvement,but also improves the impact strength of rubber/cement mortar,in addition,after the addition of micro silica powder,the peak load of the stressstrain curve of the specimen will be shifted to the left due to the shortening of the elastic deformation and elastoplastic deformation stages,but the damage stage is obviously prolonged.