多孔浮石在超高性能混凝土中的内养护机理  

Internal curing mechanism of porous pumice in ultra-high performance concrete

作　　者：张潇 ZHANG Xiao(Liaoning Provincial Communication Planning&Design Insitute Co.,Ltd.,Shenyang 110000,China;Highway Bridge Diagnosis and Treatment Technology Transportation Industry R&D Center,Shenyang 110000,China)

机构地区：[1]辽宁省交通规划设计院有限责任公司,辽宁沈阳110000 [2]公路桥梁诊治技术交通运输行业研发中心,辽宁沈阳110000

出　　处：《混凝土与水泥制品》2025年第3期28-33,共6页China Concrete and Cement Products

基　　金：辽宁省交通科技项目(202222)。

摘　　要：通过1H低场核磁共振技术,研究了多孔浮石掺量及预处理方法对其吸水-释水过程的影响,分析了浮石在超高性能混凝土(UHPC)中的内养护机理。结果表明:浮石掺量对其吸水-释水过程的影响主要体现在水分迁移的特征参数(吸水量、放水量、吸水速率、放水速率)上,且会间接影响UHPC的水化进程;浮石不同预处理方法对UHPC内部孔隙大小、分布的影响主要集中在水化早期,对水化后期基本无影响,且此现象随浮石掺量的增加而更明显;与未预湿浮石相比,预湿浮石可以延迟水分的释放时间,有利于减缓UHPC内部相对湿度的下降,从而降低UHPC的自收缩,为UHPC提供更好的内养护效果。The influence of porous pumice dosage and pretreatment methods on its water absorption-desorption process was studied using 1H low field nuclear magnetic resonance technology,and the internal curing mechanism of pumice in ultra-high performance concrete(UHPC)was analyzed.The results indicate that the influence of pumice dosage on its water absorption-desorption process is mainly reflected in the characteristic parameters of water migration(water absorption,water release,water absorption rate,water release rate),and indirectly affects the hydration process of UHPC.The influence of different pretreatment methods for pumice on the size and distribution of internal pores in UHPC is mainly concentrated in the early stage of hydration,and has little effect on the later stage of hydration.This phenomenon becomes more pronounced with the increase of pumice dosage.Compared with no pre-wetted pumice,pre-wetted pumice can delay the release time of moisture,which is beneficial for slowing down the decrease in relative humidity inside UHPC,thereby reducing the self-shrinkage of UHPC and providing better internal curing effect for UHPC.

关 键 词：多孔浮石 超高性能混凝土 吸水-释水 内养护 收缩 

分 类 号：TU528.44[建筑科学—建筑技术科学]