氧化铝空心球及玄武岩纤维对混凝土动力特性的影响

Effects of alumina bubble and basalt fiber on concrete under dynamic loading

以氧化铝空心球为轻集料,玄武岩纤维为纤维增强材料制备轻质混凝土,利用直径100 mm的分离式霍普金森压杆试验系统,研究了不同应变率下素混凝土、玄武岩纤维混凝土、氧化铝空心球混凝土以及玄武岩纤维-氧化铝空心球复合混凝土的动态力学性能。结果表明:随着应变率的提高,四种试件的动压强度、动压韧性、动压比韧性及破坏程度均不断增大,表现出显著的应变率相关性;掺入氧化铝空心球使得试件破坏程度增大,动压强度及动压韧性减小,动压比韧性提高;掺入玄武岩纤维可以有效降低试件的破坏程度,并对试件具有明显的强韧化效果;通过复掺氧化铝空心球及玄武岩纤维,可以制备得到具有良好吸能特性的轻质混凝土。

The lightweight concrete was prepared with the light aggregate of alumina bubble and reinforcing material of basalt fiber. The dynamic mechanical properties of plain concrete, basalt fiber reinforced concrete, alumina bubble concrete and basalt fiber - alumina bubble concrete were investigated by using a 100 mm diameter split Hopkinson pressure bar （SHPB） system under various strain rates. The results indicate that for all four series, the dynamic strength,dynamic toughness, specific dynamic toughness and damage degree in- crease with the increasing strain rate, which reveals obvious strain rate sensitivity. Adding alumina bubble aggravates the damage of spec- imens and results in a decrease in dynamic strength and dynamic toughness, while the specific dynamic toughness is improved. Adding basalt fiber is effective in decreasing the damage of specimens and enhancing the strength and toughness of concrete. The lightweight concrete with good energy absorption capacity can be produced by the combined use of alumina bubble and basalt fiber.