石灰-粉煤灰-煤矸石混合料强度和水泥改性后抗冻性能试验

Study on the strength and freezing resistance of lime and fly-ash and coal gangue mixture

为研究石灰-粉煤灰(二灰)-煤矸石混合料在公路基层及底基层的适用性,在对煤矸石化学成分、颗粒级配和耐久性试验研究的基础上,设计8组混合料配合比,测试了每组配合比下试件的无侧限抗压强度,试验结果表明:8组配合比均满足规范中公路基层及底基层对强度的要求,并且当煤矸石粒径为5~10 mm+10~25 mm,石灰、粉煤灰、煤矸石含量分别为10%、15%、75%时,其无侧限抗压强度最大。在此配合比的基础上,通过对掺入水泥改性混合料试件的质量损失率、强度损失以及抗冻系数的抗冻融试验表明,水泥可有效改善二灰煤矸石混合料的7 d无侧限抗压强度以及抗冻性,并且随着水泥掺量的增加,改善效果越明显。当水泥掺量为4%时,二灰煤矸石混合料的强度和抗冻性都能满足规范要求。

For the study of the suitability of lime and fly ash （lime-fly） and coal gangue mixture in the road base.Based on the chemical composition of coal gangue, particle size, durability, design 8 groups of mix ratio, specimen under unconfined compressive strength with each test experimental results show that, with the 8 groups than meet the standard in road base on the strength requirements, and when the gangne particle diameter by 5-10 mm＋10-25 ram,lime and fly-ash and coal gangue content were 10% ,15% and 75% ,the maximum unconfined compressive strength.In this mix on the basis of the quality loss of cement modified mixture specimen,the rate of loss of strength and frost resistance coefficient of the freezing thawing test shows that cement can effectively improve the lime,fly and coal gangue mixture 7 d unconfined compressive strength and frost resistance, and with the increase of cement content,improve the effect is more obvious.When the cement content is 4% ,the strength and frost resistance of lime-fly and coal gangne mixture can meet the requirements of specification.