【摘要】 采用粒径4.75～25mm的煤矸石粗骨料进行纳米SiO₂溶液强化处理，将其制备成替代率为30%的煤矸石混凝土，并掺加不同替代率的矿粉和粉煤灰，研究其对煤矸石混凝土抗压强度和抗冻性能影响。研究发现，1.5%浓度纳米SiO₂溶液对煤矸石吸水率、压碎指标的强化效果最好，较普通煤矸石粗骨料压碎指标降低22%，吸水率降低13%。强化后的煤矸石混凝土较未强化抗压强度提高约8%，约为天然碎石混凝土抗压强度的92%。矿物掺合料中，矿粉对煤矸石混凝土抗压强度和抗冻性能提升较大；复掺时，矿粉掺量为20%、粉煤灰掺量为10%，此时煤矸石混凝土28d抗压强度和抗冻性能最好。更多还原

【Abstract】 The coarse aggregate of coal gangue with particle size of 4.75～25mm is strengthened with nano-SiO2 solution to prepare coal gangue concrete with replacement rate of 30%, and the effect of different replacement rates of mineral powder and fly ash on the compressive strength and anti-freezing performance of coal gangue concrete is studied. It is found that 1.5% concentration of nano-SiO2 solution has the best effect on the water absorption and crushing index of coal gangue, which can reduce the crushing index of ordinary coal gangue coarse aggregate by 22% and water absorption by 13%. The compressive strength of the strengthened coal gangue concrete is about 8% higher than that of the unstrengthened coal gangue concrete, which is about 92% of the compressive strength of natural crushed concrete.Among the mineral admixtures, mineral powder can greatly improve the compressive strength and frost resistance of coal gangue concrete. The 28 day compressive strength and anti-freezing performance of coal gangue concrete are the best when the content of mineral powder is 20% and fly ash is 10%.更多还原