摘要
目的 研究煅烧制度对页岩火山灰活性的影响,找寻煅烧页岩作为活性掺合料在水泥基材料中的合理掺量。方法 测试煅烧页岩在不同升温速度、煅烧时间和煅烧温度下的活性指数,对煅烧页岩掺量为10%、20%、30%和40%的水泥胶砂试件进行抗压强度测试,得到其适宜掺量,并通过电化学交流阻抗谱法进行验证。结果 页岩的火山灰活性随升温速度、煅烧时间、煅烧温度的提高呈先增大后减小的变化趋势。煅烧温度为750℃时,页岩中伊利石大量分解成无定形SiO_(2)和Al_(2)O_(3)。升温速度10℃/min、煅烧时间40 min时煅烧页岩的28 d活性指数最大,达到81.2%。水泥胶砂抗压强度随煅烧页岩掺量的增加而降低,掺10%~40%煅烧页岩的水泥胶砂试件的交流阻抗Nyquist曲线呈现典型的Randles图形,交流阻抗谱法分析结果与抗压强度测试结果相吻合。结论 页岩的最佳煅烧制度为10℃/min升温速度、40 min煅烧时间、750℃煅烧温度。作为活性掺合料,煅烧页岩在水泥基材料中合理掺量不应超过30%。
In order to study the effect of calcination system on pozzolanic activity of shale,and find out the reasonable content of calcined shale as active admixture in cement-based materials,the activity indexs of calcined shale were measured at calcination tests.These tests were carried out at different heating rates,calcination times and calcination temperatures.The suitable content of calcined shale was obtained through the compressive strength of cement mortar specimens containing 10%,20%,30% and 40% calcined shale analyzed,which was verified by electrochemical impedance spectroscopy.The results show that the pozzolanic activity of shale increases at first and then decreases with the increase of heating rate,calcination time and calcination temperature.When the calcination temperature is 750 ℃,the illite in shale decomposes into amorphous SiO_(2)and Al_(2)O_(3).When the heating rate is 10 ℃/min and the calcination time is 40 min,the 28 d activity index of calcined shale is the highest,which is 81.2%.The compressive strength of cement mortar decreases with the increase of the amount of calcined shale.The AC impedance Nyquist curve of cement mortar specimens with the content of 10% ~ 40% calcined shale presents a typical Randles figure,and the results of AC impedance spectroscopy are consistent with the test results of compressive strength.The optimum calcination system for shale is 10 ℃/min heating rate,40 min calcination time and 750 ℃ calcination temperature.As an active admixture,the reasonable content of calcined shale in cement-based materials should not exceed 30%.
作者
孙小巍
黄帅
杨海明
戚红
礼航
SUN Xiaowei;HUANG Shuai;YANG Haiming;QI Hong;LI Hang(School of Materials Science and Engineering,Shenyang Jianzhu University,Shenyang,China,110168;Zhejiang Building Materials Group Co.Ltd,Hangzhou,China,310011)
出处
《沈阳建筑大学学报（自然科学版）》
CAS
CSCD
北大核心
2022年第5期888-895,共8页
Journal of Shenyang Jianzhu University：Natural Science
基金
国家自然科学基金青年基金项目(51808354)
辽宁省教育厅“兴辽英才计划”项目(xl2019tp01)
辽宁省教育厅科学研究一般项目(LJKZ0593)。
关键词
煅烧制度
页岩
火山灰活性
抗压强度
交流阻抗
calcination system
shale
pozzolanic activity
compressive strength
AC impedance
