高温对C80HPC抗压强度及超声波速的影响

Effect of high temperature on compressive strength and ultrasonic velocity of C80HPC

对C80HPC试件进行抗压强度试验与超声检测,分析聚丙烯纤维掺量对HPC高温前后混凝土爆裂现象、质量损失、抗压强度、声速变化的影响和不同超声测试距离对混凝土超声速率的影响。结果表明:掺加PP纤维可以明显抑制高温爆裂对C80HPC的影响;C80HPC试件的抗压强度随受火温度的升高而降低,当受火温度在200~300℃时,掺聚丙烯纤维的C80HPC试件抗压强度有所反弹;随着温度的升高,C80HPC试件超声声速下降,随着测距的增加,超声声速下降,下降幅度不大,可以通过超声声速探测混凝土内部损伤缺陷。建立了C80HPC抗压强度、受火温度和超声声速的关系。

The compressive strength test and ultrasonic testing of C80HPC specimens were carried out.The effects of polypropylene fiber content on concrete bursting,mass loss,compressive strength and sound velocity before and after HPC high temperature were analyzed.The effect of different ultrasonic test distances on the ultrasonic velocity of concrete was analyzed.The results showed that the addition of PP fiber can significantly inhibit the impact of high temperature burst on C80HPC.The compressive strength of C80HPC specimen decreases with the increase of fire temperature.When the fire temperature is between 200℃and 300℃,and polypropylene fiber is blended,the compressive strength of the specimens rebounded.With the increase of temperature,the ultrasonic sound velocity of the C80HPC specimen decreased.With the increase of the ranging,the ultrasonic sound velocity decreased,and the decrease was not large.The ultrasonic damage could be detected by ultrasonic sound velocity.The relationship between C80HPC compressive strength,fire temperature and ultrasonic sound velocity was established.