采用GFRP筋作为约束构件的体内不配筋混凝土板带的工作性能研究

本文建立一种基于压缩薄膜效应(Compressive Membrane Action,CMA)的采用GFRP筋作为体外约束构件的预制混凝土桥面板,并对其在静力荷载作用下的工作性能进行试验研究。通过将试验与传统桥梁面板结构进行对比发现,本文采用GFRP的新型预制桥面板与传统桥梁面板结构相比,极限承载力提高了57%左右;采用GFRP材料作为体外约束构件,合理使用面板内压缩薄膜效应作为承载机制,充分利用GFRP材料良好的抗拉性能和耐久性提高了结构的可持续性。

Study on Strengthening of RC Slabs with Different Innovative Techniques

This paper presents a focused study on using different methods to enhance the ultimate capacity of flexural behavior in RC slabs. Four RC specimens were casted with common compressive strength and reinforced with steel mesh. Specimens were strengthened with different methods such as usage of GFRP sheets, carbon fibers laminate strips and near surface mounted steel rebars. All specimens were subjected to two-point loading setup. Load was increased from zero to failure load. First crack was recorded and crack pattern was observed. The behavior of strengthened specimens was compared to that of the control specimen to judge the efficiency of the used techniques. Test results showed that the used techniques were effective in enhancing the behavior of the strengthened slabs by noteworthy values.

GFRP条带加固RC双向板试验研究

对跨中局部荷载作用下采用GFRP条带加固的RC双向板进行了试验研究，并详细分析了试件的破坏形态、承载能力、刚度、荷载-钢筋应变关系和荷载-纤维应变关系。试验结果表明：采用GFRP条带加固RC双向板可以改善板的抗裂和变形性能，且加固后板的极限承载力提高幅度达8％-15％。试验数据为后续理论分析提供了可靠的试验依据。最后，推导出局部荷载作用下粘贴GFRP加固RC双向板的极限承载力计算公式。

玻璃纤维增强复材条带与钢纤维砂浆加固损伤柱轴心受压试验研究

通过对1根未加固混凝土(RC)柱和4根加固损伤混凝土(RC)柱进行轴压试验,研究了玻璃纤维增强复材(GFRP)条带及钢纤维砂浆复合加固不同损伤程度RC方柱的轴压性能。分析了同等损伤情况下,GFRP条带对钢纤维砂浆加固损伤RC柱的约束作用;不同损伤情况下,复合加固RC柱的承载力、刚度、延性。结果表明:GFRP条带可以显著提高钢纤维砂浆加固RC柱的承载能力和延性;复合加固后损伤RC柱的承载能力显著提高,但提高幅度会随着损伤程度的增大而降低;试件轴压刚度随着损伤程度的增大而降低。基于试验建立了复合加固损伤RC方形截面短柱的轴压承载力计算式,计算值与试验结果吻合良好。