不同加入方式对高温后玄武岩纤维再生混凝土力学性能的影响

EFFECTS OF DIFFERENT MIXING METHODS ON MECHANICAL PROPERTIES OF BASALT FIBER REINFORCED CONCRETE AFTER HIGH TEMPERATURE

试验研究了在不同玄武岩纤维体积掺量(0%、0.1%、0.15%和0.2%)、不同高温(20℃、200℃、400℃、600℃)情况下,两种不同的纤维加入方式(水泥浆包裹纤维、直接加入)对再生粗骨料混凝土(取代率为50%)的立方体抗压、劈裂抗拉强度的影响,结果表明间接加入方式下的强度比高于直接加入方式,但是变量不同,提高的幅度不同。当温度一定时,抗压强度提高幅度随纤维掺量的增加而增加,0.2%时最大,劈裂抗拉强度提高幅度则随纤维掺量的增加而减小,0.1%时最大;当掺量一定时,抗压强度提高幅度随温度的变化呈折线趋势,20~200℃时上升,200~400℃时趋于平缓,400~600℃时再上升,对于劈裂而言,20~200℃时基本不变,200℃之后提高幅度急剧下降。

In this study, the effects of two different fibers （cement slurry wrapped fiber, direct incorporation） on the compressive strength and tensile strength of reinforced coarse aggregate concrete were studied under different basalt fiber volume （0%, 0. 1%, 0. 15%, 0. 2%） and high temperature（20 ℃, 200 ℃, 400 ℃, 600℃ ）. The strength ratio of the indirect mixing method was higher than that of the direct mixing method, but the variable was different and the range of the increase was different. When the temperature was kept constant, the increase ampli- tude of compressive strength is increased with the increase of fiber content, and the maximum is 0. 2%. The increase amplitude of splitting tensile strength is decreased with the increase of fiber content, and the maximum is 0. 1%. When the dosage is constant, the increasing range of compressive strength shows the trend of the broken line with the change of temperature. It presented an upward trend between 20 ℃ and 200 ℃, tended to be gentle between 200℃ and 400 ℃, and rose again between 400 ℃ and 600 ℃. The splitting tensile strength is basically unchanged with the increased amplitude between 20 ℃ and 200℃, but presented a trend of sharp decline after 200 ℃.