早强自密实补偿收缩高性能混凝土与普通混凝土基层界面抗剪性能的试验研究

Experimental Investigation on Shear Behavior of the Interface between Early-Strength Self-Compacting Shrinkage-Compensating High-Performance Concrete and Ordinary Concrete Substrate.

作者信息

Du Wenping, Yang Caiqian, De Backer Hans, Li Chen, Ming Kai, Zhang Honglei, Pan Yong

机构信息

Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 210096, China.

Department of Civil Engineering, Ghent University, 9052 Zwijnaarde, Belgium.

出版信息

Materials (Basel). 2022 Jul 15;15(14):4939. doi: 10.3390/ma15144939.

DOI:10.3390/ma15144939

PMID:35888404

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9318394/

Abstract

To improve interface bonding stress, early-strength self-compacting shrinkage-compensating high-performance concrete (ESS-HPC) was selected as an excellent strengthening material to investigate by direct shear test. Tests on seventeen Z-type specimens were carried out considering the ESS-HPC and ordinary concrete substrate (OCS) compressive strength grade, the ESS-HPC curing age, the OCS surface roughness, and the ratio of steel shear dowels as the variables. A bond stress-slip model of the interface was proposed via statistical fitting. The results show that the surface roughness and ratios of steel shear dowels had the most important influence on the shear bond stress. The shear bond stress of the specimens without steel shear dowels increased by almost 15% as the ESS-HPC strength grade changed from C60 to C75. With the increase in the curing age, the shear bond stress showed a changing trend of first increasing and then decreasing. The coarser surface with the drilling method can improve the shear bond stress by 89%. To achieve a secondary increase in the shear bond stress of specimens with steel shear dowels, the minimum ratio of steel shear dowels was 0.83%. Analytical equations are proposed in combination with the CEB-FIB Model 2010 and AASHTO Model. The calculated results show reasonable agreement with the experimental results within an acceptable range.

摘要

为提高界面粘结应力，选用早强自密实补偿收缩高性能混凝土（ESS-HPC）作为优良的加固材料，通过直接剪切试验进行研究。以ESS-HPC和普通混凝土基层（OCS）的抗压强度等级、ESS-HPC的养护龄期、OCS的表面粗糙度以及抗剪销钉比例为变量，对17个Z型试件进行了试验。通过统计拟合建立了界面粘结应力-滑移模型。结果表明，表面粗糙度和抗剪销钉比例对剪切粘结应力影响最为显著。当ESS-HPC强度等级从C60变为C75时，无抗剪销钉试件的剪切粘结应力提高了近15%。随着养护龄期的增加，剪切粘结应力呈先增大后减小的变化趋势。钻孔法形成的较粗糙表面可使剪切粘结应力提高89%。为使有抗剪销钉试件的剪切粘结应力二次增大，抗剪销钉的最小比例为0.83%。结合CEB-FIB Model 2010和AASHTO Model提出了解析方程。计算结果与试验结果在可接受范围内吻合良好。