碳纤维增强碱激发粉煤灰矿渣混凝土的高温损伤研究

Research on the High Temperature Damage of Carbon Fiber Reinforced Alkali Activated Fly Ash-Slag Concrete

本文以碳纤维、粉煤灰、矿渣、氢氧化钠、硅酸钠等为原料,制备了碳纤维增强碱激发粉煤灰矿渣混凝土(CFSC),通过抗压强度试验及超声波检测,研究了不同温度作用后CFSC的损伤特性。结果表明:高温后CFSC的抗压强度及超声波检测声速随加热温度的升高不断减小,掺入碳纤维对CFSC的温后抗压性能具有一定的增强效果,且增大纤维掺量可使同一高温下CFSC声速降幅减小;高温后CFSC抗压强度与声速间具有明显的二次多项式关系;高温导致CFSC的测试声波波形及主频发生显著变化,随着温度的升高,波形形态较常温产生畸变,声波主频不断降低,掺入碳纤维后CFSC的主频降幅较不掺纤维时有所减缓。

In this paper, the carbon fiber reinforced alkali activated fly ash-slag concrete （CFSC） was prepared by carbon fiber, fly ash, slag, sodium hydroxide, sodium silicate and so on. The damage characteristics of CFSC after high temperature were investigated by compressive strength testing and ultrasonic testing. The test results show that the compressive strength and sound velocity of CFSC decrease with the rising of temperature. The addition of carbon fiber can enhance the compressive strength and decrease the decreasing amplitude of sound velocity. The dependence of compressive strength and sound velocity of CFSC after high temperature can be expressed in the form of quadratic polynomial. The rising of temperature makes the waveform and main frequency of the acoustic signals of CFSC change significantly. The waveform distorts and the main frequency decreases with the rising of temperature, the addition of carbon fiber can reduce the decreasing amplitude of main frequency.