预应力双T板肋梁端部裂缝成因及预防措施  

Causes and Preventive Measures of End Cracks of Prestressed Double-T Ribbed Beams

作　　者：范宗帅 冯西龙 赵伟 刘航 FAN Zongshuai;FENG Xilong;ZHAO Wei;LIU Hang(China Construction Third Engineering Bureau Group Co.,Ltd.,Beijing 102629,China)

机构地区：[1]中建三局集团有限公司,北京102629

出　　处：《建筑施工》2023年第4期650-653,共4页Building Construction

摘　　要：预应力双T板属大跨度预应力构件,在生产施工中端部及翼缘处易出现结构裂缝,影响构件质量,尤其是肋梁端部裂缝将影响整体结构安全。通过对YTSB243-2型号双T板进行有限元分析,结合国内现有研究成果对双T板端部裂缝进行综合分析,总结得出双T板端部裂缝产生的原因。结果表明:双T板肋梁较薄,端部受力较为复杂是产生结构性裂缝的主要因素。同时在预应力筋放张过程中,预应力筋对双T板端部瞬时冲击力较大,致使端部混凝土破裂。根据端部裂缝出现的原因,提出避免裂缝的预防控制措施,在减少端部预应力集中、增加端部抗裂性能及减少预应力筋放张冲击力等方面采取措施,规避双T板端部开裂风险,保证预应力构件的结构安全性,同时间接提高施工效率及节约成本。Prestressed double-T plate is a large-span prestressed component.It is prone to structural cracks at the end and flange during production and construction,which will affect the quality of the component,especially the end cracks of the rib beam,and affect the overall structural safety.Through the finite element analysis of YTSB243-2 double-T plate,combined with the existing domestic research results,the end cracks of double-T plate are comprehensively analyzed,and the causes of the end cracks of double-T plate are summarized.The results show that the main factors causing structural cracks are the thin double-T ribbed beam and the complex stress at the end.At the same time,during the tensioning process of the prestressed reinforcement,the instantaneous impact force of the prestressed reinforcement at the end of the double-T plate is large,causing the end concrete to crack.According to the causes of end cracks,the prevention and control measures to avoid cracks are put forward.The measures are taken to reduce the concentration of end prestress,increase the end crack resistance and reduce the tensile impact force of prestressed reinforcement,so as to avoid the risk of double-T plate end cracks,ensure the structural safety of prestressed components,and indirectly improve the construction efficiency and save costs.

关 键 词：双T板 裂缝 预应力 原因 预防措施 

分 类 号：TU755[建筑科学—建筑技术科学]