摘要
再生混凝土具有强度及抗氯离子渗透性能较差的缺点。为解决这一问题,以不同质量分数的硅酸钠溶液改性再生粗骨料作为对照,通过立方体抗压强度试验、抗折强度试验、抗氯离子渗透试验,研究不同质量分数的碳酸钠溶液改性再生粗骨料对再生混凝土力学性能及抗氯离子渗透性能的影响。同时借助扫描电子显微镜(SEM)试验结果观察不同改性再生混凝土界面过渡区结构,并借助能量色散X射线谱(EDS)分析不同改性混凝土界面过渡区水化反应机理。结果表明:经质量分数为5%的硅酸钠溶液改性后的再生粗骨料,对由其制成的改性再生混凝土界面过渡区的强化效果最好,使得抗压强度提高最多,较未改性再生混凝土提高了18%;同时质量分数为15%的碳酸钠溶液改性后的再生粗骨料,由其制成的改性再生混凝土的水化反应最充分,使得抗折强度及抗氯离子渗透性能提高最多,其中抗折强度较未改性再生混凝土提高了24.93%,电通量较未改性再生混凝土降低31.17%。
Recycled concrete has the disadvantages of poor strength and resistance to chloride ion penetration.In order to solve this problem,it takes the recycled coarse aggregate modified by different mass fractions of sodium silicate solution as a control.Through the cube compressive strength test,flexural strength test and chloride ion penetration resistance test,the effects of different mass fractions of sodium carbonate solution modified recycled coarse aggregate on the mechanical properties and chloride ion penetration resistance of recycled concrete were studied.At the same time,the structure of interfacial transition zone of different modified recycled concrete was observed by scanning electron microscope(SEM)test results,and the hydration reaction mechanism of interfacial transition zone of different modified concrete was analyzed by energy dispersive X-ray spectroscopy(EDS).The results show that the recycled coarse aggregate modified by 5% sodium silicate solution has the best strengthening effect on the interfacial transition zone of modified recycled concrete,which makes the compressive strength increase the most,which is 18% higher than that of unmodified recycled concrete.At the same time,the recycled coarse aggregate modified by 15%sodium carbonate solution has the most complete hydration reaction of the modified recycled concrete,which makes the flexural strength and resistance to chloride ion permeability increase the most.The flexural strength is 24.93% higher than that of the unmodified recycled concrete,and the electric flux is 31.17%lower than that of the unmodified recycled concrete.
作者
王晓磊
董一夫
刘历波
WANG Xiaolei;DONG Yifu;LIU Libo(School of Civil Engineering,Hebei University of Engineering,Handan 056038,China)
出处
《混凝土》
北大核心
2025年第10期114-120,共7页
Concrete
基金
国家自然科学基金(U21A20164)。
关键词
化学改性
力学性能
抗氯离子渗透性能
界面过渡区
再生粗骨料
chemical modification
mechanical properties
chloride ion penetration resistance
interface transition zone
recycled coarse aggregate
