Experimental study on the influence of content and fineness of fly ash on the mechanical properties of grouting slurries  

作　　者：Hua Jiang Handong Zhang Xiaoyan Zhang Jinxun Zhang Yusheng Jiang 

机构地区：[1]School of Mechanics and Civil Engineering,China University of Mining and Technology,Beijing,China [2]Beijing Urban Construction Group Co.,Ltd.,Beijing,China

出　　处：《Deep Underground Science and Engineering》2024年第4期467-480,共14页深地科学（英文）

基　　金：Major Achievements Transformation and Industrialization Projects of Central Universities in Beijing,Grant/Award Number:ZDZH20141141301;National Natural Science Foundations of China,Grant/Award Numbers:51608521,51809264;Beijing Urban Construction Group Co;Outstanding Young Teachers Program by CUMTB,Grant/Award Number:2022YQLJ01。

摘　　要：Excavation gaps around the front shield can be generated during shield construction,resulting in significant ground settlement.Traditional synchronous grouting slurries are unsuitable forfilling these gaps during tunneling under existing subway lines.To address this issue,experiments are conducted on mix characteristics and hardening properties of slurries with variations infineness and contents offly ash.The experimental and computed tomography scan results yield the followingfindings:(1)fly ash with highfineness can effectively reduce the early strength of slurries and enhance their injectability.This improves thefilling effect on micropores in the slurry and ultimately enhances thefinal hardening strength.(2)Fineness offly ash controls the process of slurry hydration.The higher thefineness offly ash,the more visible the exothermic hydration of slurry and the earlier the highest temperature peak appears.(3)Fly ash with highfineness can effectively increase the density and consolidation rate of slurries,resulting in greater improvement in slurry strength,particularly when the ratio offly ash to cement(mf/mc)is 0.75.(4)Fly ash with highfineness can effectively decrease the likelihood of appearance of pores in the slurry,optimize the pore structure,and enhance the strength of slurries after consolidation.

关 键 词：CONTENT CT scan environmentally friendly FINENESS fly ash HOMOGENEITY hydration mechanism 

分 类 号：U231.3[交通运输工程—道路与铁道工程] U455.43[建筑科学—桥梁与隧道工程]