CFRP 布加固预裂钢骨混凝土梁的试验研究

通过6 根(预应力)CFRP 布加固预裂钢骨混凝土梁的试验,研究了其受力机理和破坏模式,给出了承载力的计算公式。试验结果表明,一层和二层CFRP 布、一层预应力CFRP 布、二层分别为预应力和普通CFRP 布以及对预裂程度较大梁加固后的开裂荷载分别提高了27.3%、54.5%、90.9%、100%和9.09%,相应的极限荷载分别提高了16.2%、27%、28.8%、35.1%和14.4%；普通钢骨混凝土梁的荷载-变形曲线呈现三直线特征,加固后的梁则呈现二直线特征,CFRP 布加固后梁的裂缝宽度和间距减小,但是裂缝的数量却增多；承载力计算理论公式与试验结果吻合良好。

EXPERIMENTAL RESEARCH ON PRECRACKED STEEL REINFORCED CONCRETE BEAMS STRENGTHENED WITH CFRP SHEETS

Based on the experiment of six precracked steel reinforced concrete beams strengthened with CFRP sheets, their force mechanism and failure model are discussed. The calculated formulas of bearing capacity are given. The results showed that the cracking loads of beams strengthened with one CFRP sheet, two CFRP sheets, one prestressed CFRP sheet, and two CFRP sheets with one prestressed and one normal and one CFRP sheets strengthened greater precracked beams respectively increased by 27.3%, 54.5%, 90.9%, 100% and 9.09%. The corresponding ultimate loads respectively increased by 16.2%, 27%, 28.8%, 35.1% and 14.4%. The load-deformation curves of normal and strengthened beams respectively showed three and two linear characteristics. The crack width and spacing of strengthened beams decreased, but the numbers of crack increased. The theoretical results which calculated by the formulas of bearing capacity agree well with experimental results.