基于数字图像相关技术的轻骨料混凝土早龄期细观收缩实验研究  

Experimental study on early-age meso-shrinkage of lightweight aggregate concrete based on digital Image correlation technology

作　　者：万钊航 白鹏翔 洪淼 朱飞鹏[1] 胡丰[1] 雷冬[1] WAN Zhaohang;BAI Pengxiang;HONG Miao;ZHU Feipeng;HU Feng;LEI Dong(School of Mechanics and Materials,Hohai University,Nanjing 210000,Jiangsu,China)

机构地区：[1]河海大学力学与材料学院,江苏南京210000

出　　处：《实验力学》2023年第5期549-559,共11页Journal of Experimental Mechanics

基　　金：河海大学大型仪器设备共享基金项目(GX202206B);中央高校基本科研业务费专项资金项目(B220370206,B210205019)。

摘　　要：利用数字图像相关(Digital Image Correlation,DIC)技术,对早龄期轻骨料混凝土(Lightweight Aggregate Concrete,LWAC)在细观层面上的收缩现象开展实验研究,以探索其早龄期的收缩变形规律。具体实验方法为,在3种不同的水灰比条件下,分别比较骨料是否预湿对收缩变形的影响;使用DIC技术对LWAC的收缩变形进行观测,获得LWAC表面早龄期全场应变的演变过程。结果表明,预湿处理能够对轻骨料产生内养护的作用,从而减少混凝土早龄期的收缩变形;随着水灰比的增大,内养护的效果并不会随之增强,而是表现出先升后降的趋势,在水灰比为0.40时内养护效果最佳;在早龄期骨料与砂浆两部分的最小主应变没有表现出始终一致的变化趋势,而是在一定时间段内相互背离。In order to explore the shrinkage deformation law of early-age lightweight aggregate concrete(LWAC),the shrinkage phenomenon of early-age LWAC was studied experimentally by using digital image correlation(DIC)technology.The specific experimental method was to compare the effect of aggregate pre-wetting on shrinkage deformation under three different water-cement ratio conditions.The shrinkage deformation of LWAC was observed by DIC technique,and the evolution process of full-field strain at the early age on the surface of LWAC was obtained.The results show that the pre-wetting treatment can have the effect of internal curing on lightweight aggregate,thus reducing the shrinkage deformation of concrete at the early age;with the increase of water-cement ratio,the effect of internal curing will not increase,but shows the trend of rising first and then decreasing.The curing effect is the best when the water-cement ratio is 0.40;in the early age,the minimum principal strain of aggregate and mortar does not always show a consistent change trend,but deviates from each other in a certain period of time.

关 键 词：轻骨料混凝土 数字图像相关 应变 早龄期 内养护 

分 类 号：TU502.6[建筑科学—建筑技术科学]