防灾减灾工程学报2023，Vol.43Issue(6)：1346-1357,12.DOI:10.13409/j.cnki.jdpme.20220404003
基于NSGM(1,N)模型的RTSF/PVA矿渣混凝土高温后力学性能分析及预测
Analysis and Prediction of Mechanical Properties of RTSF/PVA Slag Concrete after High Temperature Based on NSGM(1,N)Model
摘要
Abstract
To improve the mechanical properties of concrete at high temperatures,orthogonal tests with four factors and three levels were set to investigate the residual compressive strength of RTSF/PVA slag concrete at the temperatures of 200℃,400℃,600℃and 800℃,with the volume fraction of RTSF and PVA and slag replacement rate as variables.At the same time,the microstructure of RTSF/PVA slag concrete after high temperature exposure was analyzed using a scanning electron mi-croscope.A new structure multivariable grey model is used to predict the strength of RTSF-PVA/slag concrete at high temperatures.The results show that RTF-PVA/slag concrete has better crack control ability than plain concrete,and the maximum crack width at temperatures ranging from 600℃to 800℃is only 1/3～1/4 of that found in plain concrete,but the crack distribution is wider.The re-sidual compressive strength of RTSF-PVA/slag concrete decreases as the temperature increases.When the mixture of RTSF 0.6%,PVA 0.05%and GBFS 25%,the residual compressive strength of RTSF-PVA/slag concrete is 56.64%after 800℃exposure,which is 14.44%higher than plain concrete.Scanning electron microscope revealed that the matrix structure of RTSF-PVA/slag con-crete is denser.The concrete deterioration is mainly due to the decomposition of cementitious sub-stances and aggregate expansion,resulting in defects in ITZ,and the reduction of the adhesion be-tween fiber and matrix,resulting in the reduction of strength.The NSGM(1,4)model was estab-lished to predict the strength of RTSF-PVA/slag concrete after high temperature exposure.The aver-age relative error was controlled within 6.3%,and the accuracy of the model reached level ⅱ.The long-term strength prediction of RTSF-PVA/slag concrete after high temperature could be carried out according to the development coefficient judgment model.关键词
回收轮胎纤维(RTSF)/聚乙烯醇纤维(PVA)/高温损伤/微观结构/灰色预测模型Key words
RTSF/PVA/high temperature damage/microstructure/grey forecasting model分类
建筑与水利引用本文复制引用
陈东林,王学志,王晨晨,贺晶晶..基于NSGM(1,N)模型的RTSF/PVA矿渣混凝土高温后力学性能分析及预测[J].防灾减灾工程学报,2023,43(6):1346-1357,12.基金项目
辽宁省教育厅基金项目(JJL201915402)、中国电建集团西北勘测设计研究院工程实验监测院项目(SYY-KJ-2020-02)资助 （JJL201915402）
