饱和面干处理方式对再生细骨料UHPC自收缩性能的影响  

Effect of different saturated surface dry methods on the autogenous shrinkage of UHPC with recycled fine aggregate

作　　者：林添琦 孙强顺 张鸿儒 刘超 张冬 季韬[1] LIN Tianqi;SUN Qiangshun;ZHANG Hongru;LIU Chao;ZHANG Dong;JI Tao(College of Civil Engineering,Fuzhou University,Fuzhou,Fujian 350108,China;Fujian Yancheng Construction Engineering Co.,Ltd.,Xiamen,Fujian 361006,China)

机构地区：[1]福州大学土木工程学院,福建福州350108 [2]福建省燕城建设工程有限公司,福建厦门361006

出　　处：《福州大学学报（自然科学版）》2024年第3期316-321,共6页Journal of Fuzhou University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(52178121)。

摘　　要：采用预湿饱和面干和外加水饱和面干处理再生细骨料(RFA),并以RFA替代50%的河砂,制备超高性能混凝土(UHPC).研究不同处理方式获得的饱和面干RFA对UHPC抗压强度、内部相对湿度和自收缩性能的影响,并利用压汞分析进行机理解释.研究结果表明,当总水胶比为0.24时,与采用预湿饱和面干RFA的UHPC相比,采用外加水饱和面干RFA的UHPC中孔径大于50 nm的孔体积增多,抗压强度降低;内部相对湿度减少,自收缩增大;其28.0 d抗压强度仅降低3.2%,且7.0 d的自收缩仅提高10.5%.因此,在实际工程的UHPC中可采用外加水饱和面干RFA,以获得更好的施工效益.Different saturated surface dry methods,namely pre-wetting saturated surface dry and saturated surface dry by adding extra water,were used,and ultra high performance concrete(UHPC)was prepared by replacing 50%river sand with recycled fine aggregate(RFA).The effect of saturated surface dry RFA obtained by different methods on the compressive strength,internal relative humidity and autogenous shrinkage of UHPC was studied,and the mechanism was explained by mercury intrusion porosimetry test.The results show that when the total water-binder ratio is 0.24,compared to UHPC with pre-wetting saturated surface dry RFA,the UHPC with extra water saturated surface dry RFA has an increase in the volume of pores larger than 50 nm,and its compressive strength decreases.Its internal relative humidity decreases and its autogenous shrinkage increases.Its compressive strength of UHPC at age of 28.0 d is only reduced by 3.2%,and its autogenous shrinkage at age of 7.0 d is only increased by 10.5%.Therefore,in the actual project UHPC can be used to saturated surface dry RFA in order to obtain better construction benefits.

关 键 词：超高性能混凝土 饱和面干 再生细骨料 自收缩 内部相对湿度 

分 类 号：TU528.3[建筑科学—建筑技术科学] TU501