化学激发大掺量粉煤灰复合胶凝材料力学性能与水化机理研究  

Mechanical Properties and Hydration Mechanism of Chemically Activated High Content Fly Ash Composite Cementitious Materials

作　　者：窦占双 李晓民 秦宏涛[2] 魏定邦 武旭 闫升 张富强 韩方元 DOU Zhanshuang;LI Xiaomin;QIN Hongtao;WEI Dingbang;WU Xu;YAN Sheng;ZHANG Fuqiang;HAN Fangyuan(Ningxia Communications Construction Co.,Ltd.,Yinchuan 750001,China;Gansu Transportation Planning,Survey and Design Institute Co.,Ltd.,Lanzhou 730000,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]宁夏交通建设股份有限公司,银川750001 [2]甘肃省交通规划勘察设计院股份有限公司,兰州730000 [3]兰州交通大学土木工程学院,兰州730070

出　　处：《硅酸盐通报》2025年第1期243-252,共10页Bulletin of the Chinese Ceramic Society

基　　金：宁夏回族自治区重点研发项目(2022BFE02006,2022BEG02009);甘肃省科技重大专项(21ZD3GA002)。

摘　　要：本研究以大掺量粉煤灰(m(矿渣粉)∶m(粉煤灰)=1∶3(质量比))为基体,通过正交试验设计获得不同复掺方式下的复合激发剂,通过XRD、FT-IR、TG-DTG、SEM等测试方法,研究了不同激发剂单掺和复掺对大掺量粉煤灰复合胶凝体系力学性能和水化机理的影响。结果表明,单掺激发剂中对大掺量粉煤灰复合胶凝体系激发效果最佳的是Na_(2)SiO_(3),当Na_(2)SiO_(3)掺量为1.0%(质量分数)时,粉煤灰复合胶凝材料7和28 d抗压强度分别为17.5、31.7 MPa。多种激发剂复掺下对大掺量粉煤灰复合胶凝体系激发效果最佳的组合质量比为m(Ca(OH)_(2))∶m(Na_(2)SiO_(3))=2∶1,7、14 d抗压强度分别为27.5、35.5 MPa,28 d抗压强度提升至49.2 MPa,达到了42.5水泥的强度指标。这是因为在碱性环境下粉煤灰的活性物质发生二次火山灰反应,钙矾石(AFt)和水化硅(铝)酸钙(C-(A)-S-H)等水化产物逐渐增多,显著增强了胶凝材料抗压强度。本研究不仅为粉煤灰的高值化利用提供了新途径,也为固废复合材料的研发提供了参考。In this study,a high content fly ash(m(slag powder)∶m(fly ash)=1∶3(mass ratio))was used as matrix,and the composite activators under different compounding methods were obtained by orthogonal test design.The effects of different single-doped and co-doped activators on the mechanical properties and hydration mechanism of high content fly ash cementitious system were studied by XRD,FT-IR,TG-DTG,SEM and other test methods.The results show that Na_(2)SiO_(3)has the best activation effect on the high content fly ash composite cementitious system in the single-doped activator.When Na_(2)SiO_(2)content is 1.0%(mass fraction),7 and 28 d compressive strength of high content fly ash composite cementitious system is 17.5 and 31.7 MPa,respectively.The optimal mass ratio of multiple activators to the excitation effect of high content fly ash cementitious system is m(slag powder)∶m(fly ash)=1∶3.The compressive strength of 7 and 14 d is 27.5 and 35.5 MPa,respectively.The compressive strength of 28 d is increased to 49.2 MPa,reaching the strength index of 42.5 cement.This is due to the secondary pozzolanic reaction of the active substances of fly ash in alkaline environment,and the hydration products such as AFt and C-(A)-S-H gradually increase,which significantly enhances the compressive strength of the cementitious material.This study not only provides a new way for the high-content utilization of fly ash,but also provides a reference for the research and development of solid waste composite materials.

关 键 词：粉煤灰 化学激发剂 正交试验 抗压强度 水化机理 

分 类 号：TU526[建筑科学—建筑技术科学]