集中荷载下井字形CFRP与钢板条带复合加固RC双向板试验研究

Experimental Study on Two-way RC Slabs Combination Strengthened with Well-form CFRP and Steel Strips under the Concentrated Load

通过集中荷载作用下9块未加固及加固的RC双向板的试验,研究了碳纤维(CFRP)条带、钢板条带以及两者复合加固后双向板的破坏特征和受力性能.分析了不同加固方法、CFRP用量以及加固条带间距对加固板开裂荷载、极限承载力、刚度和延性等方面的影响.试验结果表明:复合加固方法充分发挥了CFRP和钢板各自的优点,两者能很好地协调工作,显著提高板的开裂荷载、极限承载力以及变形刚度,并且使加固板保持较好的延性.在一定范围内,随着CFRP用量的增加,复合加固板的承载力增大,抗弯刚度提高,但延性有所降低;随着条带间距的增加,复合加固板的开裂荷载和延性逐渐降低,抗弯刚度无明显变化.

A total of 9 pieces of unstrengthened and strengthened two-way reinforced concrete （ RC ） slabs were tested under the concentrated load. The failure types and mechanical properties of the specimens bonded external Carbon Fiber Reinforced Polymer（CFRP） ,steel strips or CFRP and steel combined strips were investigated. The influences of the different reinforcement methods, the dosage of CFRP and strip spacing on the cracking load, ultimate strength, stiffness and ductility were analyzed. The test results indicated that strengthening two-way RC slabs with CFRP and steel combined strips was effective in greatly improving the cracking load, the ultimate load capacity and the bending stiffness. The combination strengthening slabs also behave well ductility. In a certain range, with the dosage of CFRP increasing, the combination strengthening slabs showed an increasing trend in the ultimate load capacity and bending stiffness, while had a decreasing trend in ductility. With the strip spacing increasing, the combination strengthening slabs had a decreasing trend in cracking load and ductility, while had no change on bending stiffness.