钢筋再生混凝土电化学除氯效果研究  

Study on the Effect of Electrochemical Chloride Extraction Effect in Recycled Reinforced Concrete

作　　者：陈峰 屈锋[1] 王功勋[1] 程火焰[1] 黄志 金浩 CHEN Feng;QU Feng;WANG Gongxun;CHENG Huoyan;HUANG Zhi;JIN Hao(School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学土木工程学院,湖南湘潭411201

出　　处：《防灾减灾工程学报》2024年第4期952-959,共8页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金(51678234,51808213);湖南省教育厅科研项目(18C0324,19A164,20B214);湖南省自然科学基金(2019JJ50185)资助。

摘　　要：为探究遭受氯盐侵蚀钢筋再生混凝土耐久性修复路径,通过内掺氯盐方式模拟再生混凝土遭受氯盐侵蚀,开展再生混凝土电化学除氯试验,研究再生骨料特征和通电参数对电化学除氯效率的影响。研究表明,采用5~25 mm再生粗骨料粒径范围的钢筋再生混凝土电化学除氯效率是5~30 mm粒径范围钢筋再生混凝土的1.36倍;随再生粗骨料取代率增加,电化学除氯效率增大,取代率达50%时,钢筋再生混凝土除氯效率较普通混凝土提高约26%;随通电电流密度增大,再生混凝土除氯效率增大,相较1 A/m^(2),电流密度3 A/m^(2)时的电化学除氯效率是其1.45倍,电流密度从1 A/m^(2)增大到2 A/m^(2),再生混凝土除氯效率增幅比普通混凝土更明显;随除氯时间延长,再生混凝土除氯效率明显增大,相对普通混凝土,再生混凝土前期除氯效率占比更大,7 d除氯效率是28 d的51%;基于电化学除氯效率开展影响因素敏感性分析,结果表明,再生骨料取代率的影响大于再生骨料粒径,但电化学除氯时间影响最为明显。To explore the durability repair pathways of recycled reinforced concrete affected by chlo-ride salt-induced corrosion,an electrochemical chloride extraction(ECE)experiment was carried out.Chloride salts were internally added to simulate the corrosion process,and the effect of recycled aggre-gate characteristics and electrical parameters on ECE efficiency were studied.The results showed that the ECE efficiency of recycled reinforced concrete with recycled coarse aggregate sizes of 5 to 25 mm was 1.36 times higher than that of the concrete with aggregate sizes of 5~30 mm.An increased re-placement rate of recycled coarse aggregate resulted in improved ECE efficiency.At a 50%replace-ment rate,the ECE efficiency was about 26%higher than that of ordinary concrete.As current densi-ty increased during electrification,the ECE efficiency also improved.The ECE efficiency at a current density of 3 A/m^(2) was 1.45 times higher than that at 1 A/m^(2).When the current density increased from 1 A/m^(2) to 2 A/m^(2),the improvement in ECE efficiency was more pronounced for recycled concrete than for ordinary concrete.Extending ECE duration significantly enhanced its efficiency,with recycled concrete showing a substantially higher chloride removal rate in the early stages compared to ordinary concrete.The chloride extraction efficiency within the first 7 days was 51%of that achieved in 28 days.Sensitivity analysis of the factors affecting ECE efficiency showed that the recycled aggregate re-placement rate had a greater impact than aggregate particle size.However,ECE duration had the most significant impact.

关 键 词：钢筋再生混凝土 骨料粒径 再生骨料取代率 电化学除氯 电流密度 

分 类 号：TU528[建筑科学—建筑技术科学]