摘要
为了探究活性掺合料对环氧树脂修补砂浆的改性效果,为修补工程应用提供依据。研究硅灰和粉煤灰对环氧树脂修补砂浆力学性能、粘结强度、尺寸稳定性和抗冻性的影响,并采用扫描电子显微镜(SEM)和压汞法探究和分析影响机理。结果表明:环氧树脂使砂浆抗压强度降低,掺入硅灰可补偿强度损失,掺粉煤灰砂浆的强度随龄期增加而增加,但其中28 d和56 d强度低于对照组;硅灰和低掺量(≤10%,质量分数)粉煤灰可以提高修补砂浆粘结强度;硅灰对修补砂浆尺寸稳定性有不利影响,粉煤灰则相反;砂浆的抗冻性随着硅灰掺量增加先增加后降低,随着粉煤灰掺量增加而降低。
In order to explore the modification effect of active admixtures on epoxy resin repair mortar and provide basis for repair engineering application,the effects of silica fume and fly ash on the mechanical properties,bonding strength,dimensional stability and frost resistance of epoxy resin repair mortar were studied.The influence mechanism was explored and analyzed by the scanning electron microscope(SEM)and mercury intrusion method.The results indicate that epoxy resin reduces the compressive strength of mortar.Adding silica fume can make up for strength loss.The strength of mortar mixed with fly ash increases with the increase of age,but the strength of mortar at 28 d and 56 d is lower than that of the control group.Silica fume and low-content fly ash(≤10%,mass fraction)improve the bonding strength of repair mortar.However,silica fume has a negative effect on the dimensional stability of repair mortar,while fly ash has the opposite effect.The frost resistance of mortar increases first and then decreases along with the increase of silica fume content.And the frost resistance decreases with the increase of fly ash content.When epoxy resin emulsion and active admixture are mixed into mortar,the hydration products and the cured epoxy resin film form an interwoven spatial network structure to improve the compactness.And silica fume and fly ash can refine the pore size of slurry.So the improvement effect of silica fume powder is better.
作者
龚建清
李发磊
李柯
屈志刚
GONG Jianqing;LI Falei;LI Ke;QU Zhigang(College of Civil Engineering,Hunan University,Changsha 410082,China;Key Laboratory for Green and Advanced Civil Engineering Materials and Application Technology of Hunan Province,Hunan University,Changsha 410082,China)
出处
《硅酸盐通报》
CAS
北大核心
2021年第4期1137-1146,共10页
Bulletin of the Chinese Ceramic Society
关键词
环氧树脂修补砂浆
活性掺合料
抗压强度
粘结强度
尺寸稳定性
抗冻性
epoxy resin repair mortar
active admixture
compressive strength
bonding strength
dimensional stability
frost resistance
