预应力碳纤维布材加固混凝土受弯构件的抗弯性能研究

本文对预应力碳纤维布材加固混凝土梁构件的性能做了初步的研究,并提出了应用预应力碳纤维布材加固梁构件的施工工艺。在此基础上,作者进行了9根试件的试验。通过试验结果对比了预应力碳纤维布加固的受弯构件与非预应力碳纤维布加固的受弯构件的开裂荷载、极限荷载、抗弯刚度等工作性能,分析了预应力对构件弯曲性能的影响,讨论了预应力水平变化引起的构件使用荷载以及变形能力的变化。试验发现预应力碳纤维布材加固的试件的开裂荷载较对比试件提高了43%至214%,在对比试件屈服荷载下的变形为对比试件的29.8%至56.3%。试验结果与分析表明预应力碳纤维布材极大地提高了梁构件的工作性能。另外,本文提出了预应力碳纤维布材加固的受弯构件的界限补强率、极限承载力、抗弯刚度以及挠曲变形的计算公式。

Study of strengthening reinforced concrete beam using prestressed carbon fiber sheet

This paper presents a primary study o f strengthening reinforced concrete beam using prestressed carbon fiber reinforced plastics(CFRP)sheet and its constructional technology of strengthening and prestress ing.A total of 9speci-mens were tested to investigate the f lexural behavior of these beams.The strengthened beams using prestressed carbon fiber sheet were compared with stren gthened beams using non-prestresse d carbon fiber sheet on the propertie s of cracking load ,ultimate load and flexural stiffness to determine the effects of pr estressing force on these behavior.In addition,the variation of yield strength and defo rmations related to the different pr estress levels were discussed.It is shown that strengthening the beams with prestr essed CFRP sheet enhances the crack l oad by 43%to 214%;and the deformatio ns of these beams at the yield load are only29.8%to 56.3%of those strengthened with CFRP sheet without prestress.Experimental results and analysis s how that prestressing CFRP can impro ve greatly the performance of the beams.Furthermore,the equations for comp uting the limit ratio of strengthein g reinforcement,cracking load,ultimate load and deflection of such beams are propose d.