碳纖維和玻璃纖維圍束混凝土之行為

Abstract

本文係探討碳纖維和玻璃纖維纏繞於混凝土試體上，在不同參數下的力 學行為；此力學行為包括纖維對混凝土的圍束效果、混凝土的抗壓強度、韌 性、軸向應力—應變關係及軸向應力—徑向應變的關係。因為碳纖維和玻璃纖 維具有高拉力強度的關係，所以混凝土試體經由纖維纏繞後，因圍束應力增 加，進而增加抗壓強度，同時韌性也會增加，而其最大的應力與應變都會比 未纏繞纖維的混凝土高出許多。 首先以試驗方法探討纏繞纖維混凝土受軸向應力後，所反應出的各種力 學行為，研究中採用的參數包含混凝土強度、纖維種類、纖維紗束等。由試 驗結果得知，混凝土試體經由纏繞纖維圍束後，在不同參數條件下，其因圍 束應力增加而提高之抗壓強度和韌性趨勢非常一致，抗壓強度之增加量可達 3倍以上。最後以圍束混凝土理論分析的方法，模擬纏繞纖維混凝土的力學 行為，分析模式可以非常準確的預測試驗結果。 This paper was conducted to investigate the behavior of concrete cylinders wrapped with continuous carbon and glass fibers. An experiment was conducted first to study the effect of concrete confined by fibers. Concrete cylinders, with variables, were tested to failure under monotonic axial compression. Variables were the compression strength, type of continuous fibers, and layer of filaments. The study focused on the effect of confinement, ultimate compressive strength of concrete, ductility, axial stress-strain, and axial stress-radial strain relations. The results of the test indicated that the stress-strain curves of fiber confined concrete cylinders were characterized as a bilinear curve. The ultimate strength and corresponding strain reached a much higher amount. Ductility of the fiber confined cylinder is substantially increasing. Finally the behavior of the fiber confined concrete was analyzed using the Ahmad and Shah model. The results indicated that good agreement was observed.