活性粉末混凝土高温后冲击压缩特性研究
INVESTIGATION OF DYNAMIC COMPRESSION PROPERTIES OF REACTIVE POWDER CONCRETE AFTER EXPOSURE IN HIGH TEMPERATURE
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摘要: 利用分离式霍普金森压杆系统,分别对常温下、400℃、600℃及800℃高温过火后的RPC试样进行单轴冲击压缩实验.研究混杂纤维对高温过火后RPC材料抗冲击性能的影响规律.结果表明:常温下混杂纤维对RPC材料动态抗压强度和韧性均产生负混杂效应,但韧性指标降低幅度没有动态抗压强度明显.高温过火后,混杂纤维RPC 材料出现了塑性强化现象,动态抗压强度和韧性增加明显,抗冲击性能及材料完整性均优于单掺钢纤维RPC材料,出现正混杂效应.在研究范围内纤维最优体积掺量为:钢纤维2.0%、PVA 纤维0.1%.Abstract: Uniaxial-compression split Hopkinson pressure bar experiments were performed for reactive powder concrete samples. Both the untreated specimens and after-exposure concretes in high temperature (400℃, 600℃ and 800℃) were tested in order to investigate the influences of hybrid fibers on dynamic mechanisms for RPC concrete after exposure in high temperature. The results show that: without burnt, a negative-mixed effect occurs on dynamic compression strength and ductile for hybrid fibers RPC material, but less evidence decreasing rate of ductility than strength. After exposure in high temperature, a positive-mixed effect occurs on dynamic compression strength and ductility. The material shows a better impact resistant and integrity than steel fiber reinforced by RPC. And hybrid RPC behaves a plastic strengthen effect character. The sample with steel fiber of 2.0% volume rate and PVA fiber of 0.1% volume rate shows a optimal dynamic mechanical property.