纳米氧化硅和钢纤维增强再生混凝土损伤模型  

Damage model of nano-silica and steel fiber reinforced recycled concrete

作　　者：王永贵[1] 黄旭阳 李帅鹏 范玉辉[1] WANG Yonggui;HUANG Xuyang;LI Shuaipeng;FAN Yuhui(School of Civil Engineering,Henan Polytechnic University,Jiaozuo 454000,China)

机构地区：[1]河南理工大学土木工程学院,河南焦作454000

出　　处：《功能材料》2023年第5期5029-5037,共9页Journal of Functional Materials

基　　金：国家自然科学基金项目(51608179);河南省自然科学基金项目(182300410134)。

摘　　要：以纳米氧化硅和钢纤维为外加材料对再生混凝土进行改良,选定取代率、钢纤维掺量和纳米氧化硅掺量为配合比控制参数,共设计18种工况的再生混凝土。通过棱柱体受压试验分析再生混凝土应力-应变曲线变化特征,建立其损伤本构模型,分析其损伤演化机理。研究表明,随纳米氧化硅掺量增加,应力-应变曲线下降段陡峭,随着钢纤维掺量增加,再生混凝土应力-应变曲线更加饱满,分段表达式可较好表述再生混凝土应力-应变全曲线方程;单掺钢纤维或氧化硅时,随着氧化硅掺量增加,峰值应力增大、峰值应变降低,随着钢纤维掺量增大,峰值应力和峰值应变均增大;复合添加钢纤维和氧化硅时,氧化硅掺量一定时随钢纤维掺量增加,峰值应力和峰值应变均增大,随氧化硅掺量增加,峰值应力和峰值应变不具有明显规律性;建立的损伤本构模型能够较好地满足再生混凝土的应力-应变关系,损伤变量随应变增加呈S型增长,可以较好地反映出再生混凝土某一时段损伤发展。In order to improve the mechanical properties of recycled concrete,nano-silica and steel fibers were used as external materials to improve recycled concrete.The replacement rate of recycled coarse aggregate,the nano-silica content and steel fiber content are selected as the mix proportion control parameters,and a total of 18 working conditions of recycled concrete are designed.The stress-strain curve of recycled concrete was analyzed through prismatic compression test,a damage constitutive model was established,and the damage evolution mechanism is analyzed.The results show that the stress-strain curve decreases steeply with the increase of nano-silica content,and the stress-strain curve of recycled concrete becomes fuller with the increase of the steel fiber content.The subsection expression can better express the full stress-strain curve equation of recycled concrete.When the steel fiber or nano-silica is single-doped,the peak stress increases and the peak strain decreases with the increase of the nano-silica content,and the peak stress and peak strain increase with the increase of the steel fiber content.When the steel fiber and nano-silica are added together,the peak stress and peak strain increase with the increase of the steel fiber content,and the peak stress and peak strain do not have obvious regularity with the increase of the nano-silica content.The established damage constitutive model can better satisfy the stress-strain relationship of recycled concrete.The damage variable increases in S-shape with the increase of strain,which can better reflect the damage development of recycled concrete in a certain period of time.

关 键 词：再生混凝土 钢纤维 纳米氧化硅 应力-应变曲线 损伤模型 

分 类 号：TU528.09[建筑科学—建筑技术科学]