磨细循环流化床粉煤灰对泡沫轻质土力学性能和孔结构的影响  

Influence of Circulating Refined Fluidized Bed Fly Ash on Mechanical Properties and Pore Structure of Foamed Concrete

作　　者：张洪智 梁取平 邵明扬 姜能栋 杨梦宇 隋高阳 葛智 ZHANG Hongzhi;LIANG Quping;SHAO Mingyang;JIANG Nengdong;YANG Mengyu;SUI Gaoyang;GE Zhi(School of Qilu Transportation,Shandong University,Jinan 250002,China;Shandong Survey and Design Institute of Water Conservancy Co.,Ltd.,Jinan 250013,China)

机构地区：[1]山东大学齐鲁交通学院,济南250002 [2]山东省水利勘测设计院有限公司,济南250013

出　　处：《材料导报》2024年第22期50-56,共7页Materials Reports

基　　金：山东省泰山学者青年专家计划(tsqn201909032)。

摘　　要：为促进循环流化床粉煤灰(CFA)的资源化利用,减少水泥消耗量,通过粉磨细化激发CFA的反应活性,利用磨细循环流化床粉煤灰(RCFA)部分替代水泥制备泡沫轻质土。研究了RCFA掺量对复合胶凝体系需水量、凝结时间、水化热、水化产物以及对泡沫轻质土工作性能和力学性能的影响。通过X射线断层扫描和图像处理技术研究了RCFA对泡沫轻质土孔结构的影响。结果表明,增加RCFA掺量会增加复合胶凝体系的需水量,延长凝结时间,减缓水化速度,减少总水化热并提升单位水泥水化热。30%掺量下的RCFA能与水泥充分反应,改善泡沫轻质土的孔结构并提升其力学性能。更高掺量的RCFA不利于轻质土的孔结构与力学性能,但70%掺量条件下的轻质土仍能满足路基填筑力学需求。To promote the resource utilization of circulating fluidized bed fly ash(CFA)and reduce cement consumption,the reactivity of CFA was activated by grinding.Foamed concrete was prepared by partially replacing cement with refined circulating fluidized bed fly ash(RCFA).The influence of RCFA content on the water requirement,setting time,hydration heat and hydration product of the composite cementitious system,as well as the workability and mechanical properties of foamed concrete was studied.The effect of RCFA on the pore structure of foamed concrete was studied by X-ray tomography and image processing technology.The results show that increasing the amount of RCFA increased the water requirement of composite cementitious system,prolonged setting time,slowed down hydration rate,reduced cumulative hydration heat release and raised the unit cement hydration heat.At the substitution rate of 30%,RCFA can fully react with cement,improve the pore structure and mechanical properties of foamed concrete.A higher content of RCFA is detrimental to the pore structure and mechanical properties of foamed concrete.However it can still meet the mechanical needs of subgrade filling under the replacement level of 70%.

关 键 词：循环流化床粉煤灰 泡沫轻质土 力学性能 孔结构 

分 类 号：U414[交通运输工程—道路与铁道工程]