摘要:研究中位粒径为15.63、14.93、9.54μm的3种废玻璃粉,分别相同的质量分数取代10%、20%、30%的水泥制成的胶砂试件7、14、21、28、35、120 d的抗压强度比(活性指数),测定不同龄期废玻璃粉石灰溶液与粉煤灰石灰溶液pH。结果表明:取代率越大,废玻璃粉的活性指数越小;35 d以前的龄期,中位粒径为15.63、14.93μm的废玻璃粉组活性指数最大,35120 d的后期,中位粒径为9.54μm的废玻璃粉组活性指数最大;废玻璃粉组活性指数前期随着龄期的延长呈减小趋势,后期增大,120 d时达90%以上,比粉煤灰组活性指数约小15%;废玻璃粉石灰溶液与粉煤灰石灰溶液前期pH均呈减小趋势,后期增大;废玻璃粉和粉煤灰的石灰溶液均生成大量CaO-SiO2-H2O凝胶,粉煤灰石灰溶液中还有钙矾石生成,说明废玻璃粉后期有很强的火山灰活性。
关键词:废玻璃粉;火山灰活性;胶砂试件;抗压强度比
Abstract: The compressive strength ratio (activity indexes) of mortar specimens in 7, 14, 21, 28, 35, 120 d were studied which were prepared by three kinds of waste glass powders with median diameter of 15.63, 14.93, 9.54 μm substituting 10%,20% and 30% cements with the same mass fraction. The pH values of waste glass powders lime solution and fly ash lime solution in different ages were determined. The results show that the higher the replace rate is, the lower the activity index is. In the early stage of before 35 d, waste glass powders groups with the diameter of 15.63, 14.93 μm have the high activity index. During the latter stage of 35~120 d, 9.54 μm group was the most active. In the early stage, the activity index of waste glass powders group decreases with the extension of the age, and increases during the latter stage. In 120 d, more than 90% can be reached which is about 15% lower than the activity index of fly ash group. The pH values of waste glass powders and fly ash lime solution decrease in the early stage, and increase during the latter stage. The waste glass powders and fly ash lime solution generate a large number of CaO-SiO2 -H2O, and ettringite is generated in fly ash lime solution, which shows that waste glass powders have very strong pozzolanic activity during the latter stage.
Keywords: waste glass powder; pozzolanic activity; mortar specimen; compressive strength ratio