钢纤维增强地聚物再生混凝土单轴受压全曲线试验  

Experiments on stress-strain curve of steel fiber reinforced geopolymer recycled concrete under uniaxial compression

作　　者：赵秋红[1,2] 董硕 谢萌 ZHAO Qiuhong;DONG Shuo;XIE Meng(School of Civil Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Coastal Civil Structure and Safety of China Ministry of Education,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学建筑工程学院,天津300072 [2]天津大学滨海土木工程结构与安全教育部重点实验室,天津300350

出　　处：《建筑结构学报》2022年第11期255-265,共11页Journal of Building Structures

基　　金：国家自然科学基金项目(51678406,51878447)。

摘　　要：为增强再生混凝土的抗压强度及延性,并进一步减少水泥制备造成的碳排放,采用粉煤灰/矿渣基地聚物100%取代再生混凝土中的普通硅酸盐水泥,并掺入钢纤维制备出钢纤维增强地聚物再生混凝土(SFGRC)。为研究其抗压性能,配制得到再生粗骨料取代率分别为0%、30%、50%、70%和100%,及钢纤维体积掺量分别为0%、0.5%、1.0%和1.5%的14组钢纤维增强地聚物再生混凝土试件,并进行单轴受压全曲线试验。结果表明:随着钢纤维的掺入,SFGRC的破坏模式由脆性向延性转变;立方体抗压强度、峰值应力对应应变、受压韧性及延性随钢纤维掺量的增加而增加;立方体抗压强度、弹性模量及受压韧性随再生粗骨料取代率的增加而降低,但峰值应力对应应变增加。引入钢纤维体积掺量和再生粗骨料取代率,对Carreira-Chu混凝土单轴受压本构模型的下降段进行修正,提出了适用于SFGRC的单轴受压本构模型,其计算结果与相应试验结果均吻合良好。In order to improve the compressive strength and ductility of recycled concrete,and further decrease the carbon emission during the concrete production,ground granulated blast slag and fly ash based geopolymer were used to replace 100%of the portland cement,and steel fibers were added to produce the steel fiber reinforced geopolymer recycled concrete(SFGRC).Fourteen groups of SFGRC specimens were prepared,with recycled coarse aggregates replacement rate of 0%,30%,50%,70%and 100%and steel fibers volume fraction of 0%,0.5%,1.0%and 1.5%,and uniaxial compression tests were conducted to study the compressive behavior of SFGRC.The results show that the failure mode of SFGRC changes from brittle to ductile with the addition of steel fibers.The compressive strength,the strain at peak stress,compressive toughness and ductility of SFGRC increase with the steel fiber volume fraction.The compressive strength,elastic modulus and compressive toughness of SFGRC decrease,but the strain at peak stress increases with the recycled coarse aggregate replacement rate.The steel fiber volume fraction and the recycled coarse aggregate replacement rate were introduced to modify the post-peak stage of the Carreira-Chu stress-strain constitutive model for nature concrete,and a modified stress-strain constitutive model was proposed for SFGRC,which matches well with the compression test results in this paper and literatures,and provides a theoretical reference for the application of SFGRC in engineering.

关 键 词：钢纤维增强地聚物再生混凝土 钢纤维体积掺量 再生粗骨料取代率 单轴受压试验 应力-应变全曲线 本构模型 

分 类 号：TU528.31[建筑科学—建筑技术科学] TU528.572