纳米再生骨料混凝土的动态力学性能试验研究

对再生混凝土以及经过1%~2%的纳米SiO2或纳米CaCO3改性的再生混凝土进行了霍普金森压杆（SHPB）的冲击对比试验研究.试验研究不同纳米颗粒及其不同掺量对再生混凝土高应变率作用下动态强度，动态增长因子（DIF），峰值应变，冲击韧性等力学性能的影响.试验结果表明，动态冲击荷载下纳米改性再生混凝土普遍具有比未添加纳米颗粒的再生混凝土更高的冲击强度，然而当纳米颗粒含量从1%增加到2%时，纳米SiO2及纳米CaCO3改性的再生混凝土受冲击强度均有所降低.相同掺量时，纳米SiO2对受冲击强度的提高效果比纳米CaCO3更为明显，掺入1%纳米SiO2的再生混凝土具有最高的受冲击强度.纳米CaCO3则表现为更有效地提高了再生混凝土的冲击韧性和变形能力.纳米改性再生混凝土均呈现出比未添加纳米材料的再生混凝土低的应变率敏感性.
The dynamic mechanical performances of recycled aggregate concrete （RAC） incorporating with 1% to 2% nano-SiO2 or nano-CaCO3 were tested by Split Hopkinson Pressure Bar （SHPB）.The effects of different kind is of nanoparticles and different dosages on the mechanical performances of RAC were investigated.The results revealed that RACs with nano-SiO2 and nano-CaCO3 all zhowed higher dynamic compressive strength than the control RAC,and the nano-SiO2 was more effectire than nano-CaCO3 in enhancing the dynamic compressive strength of RAC.But RACs with high dosage of nano-SiO2 or nano-CaCO3 usually showed lower dynamic compressive strength than that of low dosage one,and the RAC incorporating with 1% nano-SiO2 achieved the highest dynamic compressive strength.Nano-CaCO3 exhibited more advantage in improving the deformation performance and energy absorption capacity of RAC.Both nano-SiO2 modified RAC and nano-CaCO3 modified RAC showed lower dynamic increase factor than control RAC.