摘要
为研究早龄期持续受荷对成熟混凝土构件的影响。针对16根龄期在72 h以内的早龄期钢筋混凝土梁,分别施加不同程度荷载并持荷不同时长,卸载后自然养护至28 d进行四分点抗弯试验,探讨其持荷龄期、持荷大小、持荷时长等因素下早龄期混凝土梁的破坏形态、梁截面刚度等基本力学影响规律。试验结果表明:持荷龄期、持荷时长及持荷大小三因素对早期持荷梁28 d后的破坏形态、屈服弯矩及极限弯矩影响较小;开裂弯矩受持荷时长及持荷大小的影响较为显著,即持荷时间越长,持荷值越大,其开裂弯矩降低越多。参考规范开裂弯矩计算式对试验值进行对比,发现持荷龄期为14 d或早期施加极限承载力的45%和60%的条件下,其规范结果明显偏大而不适宜采用,仍需要进一步的探讨。
To study the effect of early age sustained loading on mature concrete members.For 16 early-age reinforced concrete beams with the age of less than 72 h,different degrees of load were applied and loaded for different times.After unloading,they were naturally cured to 28 days for a quarter-point bending test.The basic mechanical effects of load age,load value and load time on the failure mode and beam section stiffness of early-age concrete beams were discussed.The test results show that the three factors of load age,load value and load time have little effect on the failure mode,yield bending moment and ultimate bending moment of the early loaded beam after 28 days.The cracking moment is significantly affected by the load time and load value,that is,the longer the load time and the larger the load value are,the more the cracking moment decreases.The test values are compared by referring to the calculation formula of cracking moment in the specification.It is found that when the load age is 14 d or the ultimate bearing capacity is 45%and 60%of the early application,the specification results are obviously too large to be used,which still needs further discussion and analysis.
作者
庄金平
任凯
杨尊煌
ZHUANG Jinping;REN Kai;YANG Zunhuang(Fujian Provincial Key Laboratory of Advanced Technology and Informatization in Civil Engineering,Fujian University of Technology,Fuzhou 350118,China;School of Civil Engineering,Fujian University of Technology,Fuzhou 350118,China)
出处
《混凝土》
CAS
北大核心
2023年第11期49-52,57,共5页
Concrete
基金
国家自然科学基金(51678152)
福建省自然科学基金(2021J011063)
福建省高校新世纪人才项目(GY-Z17069)。
