纤维增强复合材料加固钢筋混凝土单向板受弯性能研究

通过纤维增强复合材料（FRP）布加固钢筋混凝土单向板的受弯性能试验，研究了FRP布种类、层数、宽度、粘贴方式和锚固措施等因素对加固效果的影响。结果表明：在板底粘贴CFRP布和高强GFRP布均可明显提高钢筋混凝土单向板的受弯承载力和纵筋屈服后刚度。当采用横向粘贴1层U形CFRP布条作为端部锚固措施时，所有加固单向板试件的破坏模式均为跨中弯曲裂缝引起的剥离破坏。当FRP布宽度和层数相同时，采用CFRP布加固效果优于高强GFRP布加固。与对比试件相比，FRP布加固钢筋混凝土单向板试件的位移延性略有降低。高强GFRP布加固钢筋混凝土单向板的位移延性优于CFRP布加固钢筋混凝土单向板。FRP布的粘贴方式对FRP加固钢筋混凝土单向板的位移延性也有影响，单层FRP布加固单向板试件的延性较好。通过对试验结果的分析，提出了FRP布加固钢筋混凝土单向板构件受弯破坏模式的判别方法，验证了已有文献和GB 50608-2010《纤维增强复合材料建设工程应用技术规范》中给出的跨中弯曲裂缝引起的FRP剥离应变计算公式对FRP布加固混凝土单向板的适用性，建立了FRP布加固钢筋混凝土单向板受弯承载力计算方法。

Flexural performance of reinforced concrete one-way slabs strengthened with fiber reinforced polymer sheets

Experiments on the reinforced concrete one-way slabs strengthened with fiber reinforced polymer (FRP) sheets were conducted to study the influences of the type of fiber sheets, the number of fiber sheet layers, width of fiber sheet, bonding types and anchorage methods on its flexural performance. Results show that the bearing capacity and the rebar post-yield stiffness of the reinforced concrete one-way slabs can be significantly improved through strengthening CFRP sheets and high strength GFRP sheets under the slab bottom. When using one layer of transverse U-shape CFRP sheet strip as the end anchorage measures, the failure modes of all the specimens are CFRP sheets debonding that is induced by intermediate crack. When the layers and width of the FRP sheets are all the same, the strengthening effect of using CFRP sheets is better than using the high-strength GFRP sheets. Compared to the control specimen, the ductility of reinforced concrete one-way slabs strengthened with the high-strength GFRP sheet is better than CFRP sheets， both of which are lower than that of the normal RC slabs. The bonding way of FRP sheets has an effect on the ductility of the reinforced concrete one-way slabs while the ductility of the reinforced concrete one-way slab specimens strengthened with single layer of FRP sheet is optimal. Method for distinguishing failure mode of reinforced concrete one-way slab member reinforced with FRP sheet is proposed through analysis. Meanwhile, the applicability of the intermediate crack-induced debonding strain prediction formulas, which are given in the literature and in GB 50608-2010‘Technical code for infrastructure application of FRP composites’, is checked when they were used for the reinforced concrete one-way slabs strengthened with FRP sheets. Meanwhile, the method for calculating the flexural capacity of reinforced concrete one-way slabs strengthened with FRP sheets is established.