玻璃粉对玻璃骨料混凝土力学性能和ASR影响的研究

Study on the effect of glass powder on mechanical properties and ASR of glass aggregate concrete

ASR膨胀是限制废弃玻璃作为细骨料运用到混凝土中的主要因素之一,玻璃粉具有潜在的火山灰活性,当一定细度的玻璃粉替代部分水泥可以有效的抑制ASR同时还可以增强混凝土后期强度;在玻璃细骨料混凝土(细骨料替代率分别为10%、20%、30%)中采用玻璃粉取代20%作为辅助胶凝材料,通过混凝土抗压试验和砂浆棒试验,研究玻璃粉对玻璃细骨料混凝土力学性能及ASR影响;研究表明,玻璃粉掺入可以提升玻璃细骨料混凝土后期强度,特别是90 d后玻璃粉混凝土抗压强度超越普通混凝土;同时,玻璃粉可以有效抑制玻璃细骨料混凝土ASR,掺入20%玻璃粉的玻璃细骨料混凝土14 d砂浆棒膨胀率均小于规范限定值0.1%,而未掺入玻璃粉的试件恰恰相反。所以,玻璃粉可以有效的改良玻璃细骨料混凝土的后期强度和ASR膨胀不足。

ASR expansion is one of the main factors limiting the application of waste glass as fine aggregate in concrete.Glass powder has potential pozzolanic activity.When the glass powder with a certain degree of fineness replaces part of cement,it can effectively restrain ASR and enhance the later strength of concrete.In the glass fine aggregate concrete(the replacement rate of fine aggregate is 10%,20%and 30%respectively),the glass powder is used instead of 20%cement as the auxiliary cementitious material.The effects of glass powder on the mechanical properties and ASR of glass fine aggregate concrete were studied by concrete compression test and mortar bar test.The results show that the addition of glass powder can improve the late strength of glass fine aggregate concrete,especially,the compressive strength of glass powder concrete is higher than that of ordinary concrete after 90 days.And,the glass powder can effectively restrain the expansion rate of the mortar bar of the glass fine aggregate concrete mixed with 20%glass powder for 14 days,which is less than 0.1%of the standard limit value,while the specimen mixed without glass powder is just the opposite.Therefore,glass powder can effectively improve the late strength and ASR deficiency of glass fine aggregate concrete.