玄武岩纤维混凝土抗冲击性能的试验研究

Experimental study on the effect of impact resistance of basalt fiber reinforced concrete

参考美国ACI 544规定,采用带导轨的自制落锤试验装置及抗弯冲击装置,研究普通混凝土、玄武岩纤维混凝土的冲压及动态抗弯冲击性能。结果表明,掺量为3.15 kg/m3的玄武岩纤维混凝土的抗冲击能力最强,破坏冲击次数最大,达到117次,试件初裂和破坏时冲击次数的差值达到25次,冲击功为2030.3 N.m,冲击延性指标比素混凝土提高166.7%。冲压加载下,素混凝土的破坏呈现出明显的脆性断裂,断口基本呈一字型,断口较为整齐,玄武岩纤维混凝土产生数条由中间向四周逐步开展的裂纹,呈放射状分布。动态抗弯冲击下,素混凝土断口较为平整,不同掺量的玄武岩纤维混凝土梁断口有一定弧形。冲压和抗弯冲击下,玄武岩纤维混凝土表现出较明显的"塑性"性质。

Refer to the stipulation of USA ACI 544 Committee,impact resistance behaviors of ordinary concrete and basalt fiber reinforced concrete were measured using self-made drop weight equipment and flexural impact equipment. Results show that： Impact resistances of concrete with basalt fiber content 3.15 kg/m3 is strongest,final cracking times of concrete with basalt fiber 3.15 kg/m3 is equal to 117. Difference with initial cracking times and final cracking times is 25 times and the impact energy is 2030.3 N.m,impact ductility index increased by 1.66.7% than that of plain concrete. Under punching load,the fracture surface of the plain concrete appears as brittle fracture mode,and the fracture is relatively neat. Basalt fiber reinforced concrete produces a few cracks that gradually expand from the middle to surrounding. Under the dynamic flexural impact, the fraction of the plain concrete is relatively flat, and that of the basalt fiber reinforced concrete beams with different dosage has a certain curve. Basalt fiber reinforced concrete appears as ＂plastic＂ fracture mode under punching load and dynamic bending tension.