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完成了聚丙烯纤维(PPF)体积掺量分别为0、0.1%、0.2%和0.3%的活性粉末混凝土(RPC)经20～900℃后的力学性能试验,包括70.7 mm×70.7 mm×70.7 mm立方体受压试验、70.7 mm×70.7 mm×228.0 mm棱柱体受压试验、40 mm×40 mm×160 mm棱柱体受折试验和“8”字形试件轴心受拉试验。考察了PPF对RPC高温爆裂的抑制效果,分析了PPF掺量和经历温度对RPC高温后力学性能(残余立方体抗压强度、残余轴心抗压强度、残余抗折强度和残余轴心抗拉强度)的影响。结果表明:PPF体积掺量0.1%和0.2%时对RPC高温爆裂的抑制作用不明显,体积掺量0.3%时可以防止RPC发生爆裂;常温下PPF的掺入对RPC力学性能有不利影响,经历温度高于200℃时,随PPF掺量的增大高温后RPC力学性能相应提高;掺PPF的RPC高温后残余抗压强度、残余抗折强度和残余轴心抗拉强度均随经历温度的升高先增大后减小,3种强度的临界温度分别为300℃、300℃和120℃。根据试验统计数据建立了高温后PPF体积掺量不同的RPC残余抗压强度、残余抗折强度和残余轴心抗拉强度随温度变化的计算式。
The mechanical properties tests of reactive powder concrete (RPC) with volume fraction of polypropylene fiber (PPF) of 0, 0.1%, 0.2% and 0.3% after 20 ~ 900 ℃ were completed, including 70.7 mm × 70.7 mm × 70.7 mm Cube compression test, prismatic compression test of 70.7 mm × 70.7 mm × 228.0 mm, prismatic folding test of 40 mm × 40 mm × 160 mm and axial tensile test of “8” -shaped specimen. The inhibitory effect of PPF on high temperature burst of RPC was investigated. The effects of PPF content and temperature on the mechanical properties (residual cuboidal compressive strength, residual axial compressive strength, residual flexural strength and residual axial tensile strength )Impact. The results showed that PPF at 0.1% and 0.2% volume fraction had no obvious inhibitory effect on high temperature burst of RPC. RPC at volume content of 0.3% could prevent the burst of RPC. PPF incorporation at room temperature had an adverse effect on mechanical properties of RPC. When the temperature is higher than 200 ℃, the mechanical properties of RPC increases with the increase of PPF content. The residual compressive strength, residual flexural strength and residual axial tensile strength of RPC with PPF are higher with increasing temperature When the height first increases and then decreases, the critical temperatures of the three kinds of strength are respectively 300 ° C, 300 ° C and 120 ° C. Based on the experimental statistics, the formula of RPC residual compressive strength, residual flexural strength and residual axial tensile strength with temperature were established after high temperature.