基于养护龄期的煅烧煤矸石细集料砂浆X射线衍射及扫描电镜分析

Based on Curing Age of Calcined Coal Gangue Fine Aggregate Mortar of X-Ray Diffraction and Scanning Electron Microscopy Analysis

采用X射线衍射法(XRD)和环境扫描电镜(SEM)分析方法,研究了不同煅烧温度下煤矸石细集料的活性,针对活性最高的700℃高温煅烧煤矸石细集料砂浆的水化产物、微观结构和强度进行了探讨,并分析了砂浆强度随养护龄期(3,7,14,28,60和90d)增长的变化规律。试验研究表明:煤矸石细集料随着煅烧温度的升高,其活性逐步增加,当煅烧温度达到700℃左右时,煤矸石细集料的活性达到最高,当煅烧温度继续升高时,活性呈下降趋势。经过700℃高温煅烧的煤矸石细集料具有明显的火山灰活性,其活性组分SiO2和Al2O3能与水泥水化产物发生一定程度的二次水化反应,通过对不同养护龄期的活性最高的700℃高温煅烧煤矸石细集料砂浆XRD和SEM分析可知,随着养护龄期的增长,二次水化反应将更加充分,而且水化产物的数量也逐步增多,与早龄期的水泥砂浆相比,生成物相更为稳定的水化产物填充在砂浆的微观孔隙中,能够进一步改善砂浆的微观结构,增强砂浆的界面性能,使砂浆内部结构更加均匀,煅烧的煤矸石细集料和水泥砂浆更趋为一个坚固连续的整体,水泥硬化砂浆的后期强度有较大增幅,活性最高的700℃高温煅烧煤矸石细集料火山灰效应明显。

By using X-ray diffraction（XRD）and environmental scanning electron microscope（SEM）analysis method,we studied the activity of coal gangue fine aggregate under different calcination temperature.In view of the activity of the highest 700℃high temperature calcined coal gangue fine aggregate mortar of hydration products,microstructure and strength were discussed in this paper,and the change laws of mortar strength with curing age（3,7,14,28,60 and 90d）growth were analyzed.Test results showed that coal gangue fine aggregate with the increase of calcination temperature,the active gradually increases.When the calcination temperature reaches 700℃,the activity of coal gangue fine aggregate is the highest.When calcining temperature continues to rise,activity falls.After 700 ℃ high temperature calcined coal gangue fine aggregate has obvious ash activity,the active components of SiO2 and Al2O3can be with cement hydration products in a certain degree of secondary hydration reaction.Through on the top of the activity of different curing age 700 ℃ high temperature calcined coal gangue fine aggregate mortar,XRD and SEM analysis showed that with the increase of curing age,secondary hydration reaction will be more fully,and the amount of hydration products also gradually increases.Compared with the early ages of the cement mortar,the products are more stable hydration products filling in mortar microscopic pore,which can further improve the microstructure of mortar,strengthen the interface performance of the mortar.The mortar internal structure is more uniform,calcined coal gangue fine aggregate and cement mortar are more of a strong continuous whole,which increase the later strength of hardened cement mortar,700℃ high temperature calcined coal gangue fine aggregate pozzolanic effect is obvious.