高温后橡胶粉掺量对高强混凝土抗压强度的影响

Influence of rubber powder content on compressive strength of high-strength concrete after high temperature

设置了6个不同温度梯度、3种橡胶粉掺量,来研究高温后橡胶粉掺量对高强橡胶混凝土抗压强度及其离散性的影响,并采用压汞法探究温度、橡胶粉掺量对橡胶混凝土内部孔结构的影响规律。研究表明:同一温度下,橡胶混凝土抗压强度随橡胶粉掺量的增加而降低,抗压强度离散性降低;同一橡胶粉掺量水平下,高温后混凝土抗压强度降低,而抗压强度离散性随温度的升高出现先增加后减小的现象,400℃时橡胶混凝土抗压强度离散性最大;并且随着温度的升高,橡胶粉的掺入量,对抗压强度的影响程度逐渐减弱。常温下,随着掺量的增加,最可几孔径略微增加,并且具有向大孔移动的趋势;当橡胶粉掺量为6%,300℃时最可几孔径升高,但升高幅度不大,强度下降幅度较小;500℃时最可几孔径明显右移,橡胶混凝土强度大幅下降。

Set up six different temperature gradient, three kinds of crumb rubber powder amount, the influence of rubber powder contenton compressive strength and its separation of concrete after the high temperature, and explore the influence of temperature andrubber pow-der content on inside pore structure ofrubber concrete by mercury pressure.Research shows that：under the same temperature, with the in-crease of rubber powder content, the compressive strength and its separation of rubber concrete is decreased gradually.At the rubber pow-der content level, as the temperature increases, the compressive strength is decreased and the separation of compressive strength was firstincreased and then decreased trend.When the temperature reached 400 ℃, the discreteness of compressive strength maximum.And with theincrease of temperature, the influence degree of rubber powder content on the compressive strength gradually weakened.At normal temper-ature,with the increase in the volume of the most probable pore size slightly increased,and has to macroporous moving trend.When therubber powder content is 6%, 300 ℃ most probable pore size increased,but the increase was small, the strength decreased a little.500 ℃,the most probable pore size is shifled to the right, increase strength of rubberized concrete dropped significantly.