不同侵蚀环境下水下不分散混凝土抗Cl-和SO_(4)^(2-)渗透性能研究  

Study on the impermeability for chloride ion and sulfate ion of non dispersible concrete under different erosion environments

作　　者：于泽 艾红梅[1] 王万里 王宝民[1] 韩俊楠 YU Ze;AI Hongmei;WANG Wanli;WANG Baomin;HAN Junnan(School of Civil Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学土木工程学院,辽宁大连116024

出　　处：《混凝土》2024年第3期61-67,共7页Concrete

摘　　要：在不同侵蚀环境中的水下不分散混凝土会受到侵蚀离子的渗透,严重影响水下不分散混凝土的耐久性能。研究了不同强度等级的水下不分散混凝土在氯盐溶液、硫酸盐溶液和复合盐溶液3种侵蚀环境下抵抗侵蚀离子渗透的能力。通过分析不同矿渣掺量下抗侵蚀离子渗透性能的影响,探究Cl^(-)和SO_(4)^(2-)在渗透过程中的耦合作用,并利用AutoPoreIV9500压汞仪测试不同侵蚀龄期各试样的孔隙特征。结果表明:在距离侵蚀表面5 mm和30 mm处,C35混凝土比C25混凝土的离子浓度降低7%~60%;在相同侵蚀环境下,掺入矿渣粉可以显著减小水下不分散混凝土中侵蚀离子浓度;水下不分散混凝土中的孔隙组成以直径小于50 nm的介孔和微孔为主,矿渣的掺入细化了孔隙结构。即水下不分散混凝土的抗渗性能随着其抗压强度等级的提高而显著提高,并且矿渣粉的掺入使结构更加致密,从而有效提高混凝土抗Cl^(-)和SO_(4)^(2-)渗透性能。Non-dispersible concrete in different erosion environments will be penetrated by erosion ions,which will seriously affect the durability of non-dispersible concrete.In this experiment,the resistance of non-dispersible concrete with different strength grades to erosion ion penetration in chloride solution,sulfate solution and composite salt solution was studied.Through the analysis of the influence of different slag content on its anti-erosion ion permeability,the coupling effect of Cl^(-) and SO_(4)^(2-)in the infiltration process is explored,and the pore characteristics of each sample at different erosion ages are tested by AutoPore IV 9500 mercury intrusion instrument.The results show that the ion concentration of C35 concrete is from 7%to 60%lower than that of C25 concrete at 5 mm and 30 mm away from the erosion surface.Under the same erosion environment,adding slag powder can significantly reduce the concentration of erosion ions in non-dispersible concrete.The pore composition in non-dispersible concrete is mainly mesoporous and microporous with diameter less than 50 nm.The addition of slag refines the pore structure,it means that the impermeability of non-dispersible concrete is significantly improved with the increase of its compressive strength grade,and the addition of slag powder makes the structure more compact,so as to effectively improve the impermeability of Cl^(-) and SO_(4)^(2-)of concrete.

关 键 词：水下不分散混凝土 矿渣粉 抗侵蚀离子渗透 孔结构 

分 类 号：TU528.01[建筑科学—建筑技术科学]