不同掺加剂条件下轻质充填材料强度演化特征研究

Study on Strength Evolution Characteristics of Light Filling Materials under Different Additive Conditions

掺加剂对轻质充填材料强度产生重要影响,研究不同掺加剂条件下轻质充填材料的强度演化特征具有重要意义。根据不同掺加剂条件下轻质充填材料试验结果,分析了水灰比、粉煤灰和浆液密度对轻质充填材料强度的影响,研究结果表明:不同水灰比条件下轻质充填材料强度抗压强度整体上升,并且增长率先增加后减小,当水灰比自0.5增加至0.7时,试件的28d单轴抗压强度由3.76MPa减小至2.75MPa。粉煤灰能够改善轻质充填体的后期强度,粉煤灰的二次水化作用,能够有效增加轻质充填体后期的强度。轻质充填体抗压强度随着浆液密度的升高而不断增大,随着浆液密度的增大,材料固结体气孔率及气孔孔径减小,轻质充填体强度增加。

Additives have an important effect on the strength of light filling materials,so it is of great significance to study the strength evolution characteristics of light filling materials under different additives.According to the test results of light filling materials under different additive conditions,the influences of water-cement ratio,fly ash and slurry density on the strength of light filling materials were analyzed.The research results showed that:Under the conditions of different water-cement ratios,the strength and compressive strength of light filling materials increase as a whole,and the growth increases first and then decreases.When the water-cement ratio increases from 0.5 to 0.7,the 28d uniaxial compressive strength of the specimen decreases from 3.76MPa to 2.75MPa.Fly ash can improve the late strength of light backfill,and the secondary hydration of fly ash can effectively increase the late strength of light backfill.The compressive strength of light backfill increases with the increase of slurry density.With the increase of slurry density,the porosity and pore size of the material consolidated body decrease,and the strength of light backfill increases.