摘要
新旧混凝土黏结面的剪切强度是衡量黏结性能的重要指标。采用Z形直剪试验,分析新、旧混凝土强度、粗糙度、界面剂以及黏结龄期对剪切强度的影响,根据试验结果建议实际工程中新混凝土应较旧混凝土强度等级提高一级,粗糙度宜处理至4-6 mm,水泥净浆或掺U型膨胀剂水泥浆作为界面剂较为经济实用,加固黏结期应注重养护,90 d内避免过大荷载。对212组试验结果进行多元回归分析,提出剪切强度改进计算公式,该公式较已有理论公式与试验结果的吻合度更高且离散性更小,可供混凝土加固设计计算时参考采用。
Shear strength is an important index of the bonding performance of new and old concrete. The direct shear tests of Z-shaped adhesive specimens were conducted to study the shear strength of new and old concrete.The major factors on the bonding shear strength were considered,such as strength of new and old concrete,roughness,interface agent and bonding ages. According to the results of experiment,it was suggested that new concrete would be one level higher than the old one,roughness would be 4 ~ 6 mm,cement paste and cement paste with UEA would be more economical and practical,excessive load would be avoid within 90 days. An improved formula for shear strength was proposed from multiple regression analysis on the basis of 212 test results. Compared with existing theoretical formulas, the improved formula agreed much better with the experimental results,and the dispersion was much smaller. The improved formula could be applied in design of structure members reinforced with concrete.
作者
黄璐
卓卫东
上官萍
黄新艺
HUANG Lu;ZHUO Weidong;SHANGGUAN Ping;HUANG Xinyi(College of Civil Engineering,Fuzhou University,Fuzhou 350116,China;Key Laboratory for Multi Disaster Prevention and Governance of Civil Engineering of Fujian Province,Fuzhou University,Fuzhou 350116,China)
出处
《工业建筑》
CSCD
北大核心
2018年第8期202-207,212,共7页
Industrial Construction
基金
厦门市建设与管理局科技项目(2014-2-8)
关键词
新旧混凝土黏结面
直剪试验
剪切强度
计算公式
new and old concrete interface
direct shear experiment
shear strength
calculation formula
