工學院: 土木工程學研究所指導教授: 廖文正李昆穎LEE, KUN-YINGKUN-YINGLEE2017-03-132018-07-092017-03-132018-07-092016http://ntur.lib.ntu.edu.tw//handle/246246/277975握裹應力為鋼筋與混凝土表面間的剪應力，是鋼筋混凝土中最基本且重要的力學關係，藉由良好的握裹應力將鋼筋與混凝土連結互鎖，形成預期的複合材料結構共同抵抗外力。其中，鋼筋表面之相對節面積Rr為影響鋼筋與混凝土間握裹應力的重要因素，美國ACI 408委員會建議竹節鋼筋之相對節面積Rr 值應介於0.10 至0.14 間，以確保握裹性能。 本研究主要針對工程上廣泛採用的竹節鋼筋進行研究，探討不同相對節面積Rr之SD420W竹節鋼筋與普通/高強度混凝土間之握裹行為，目的在驗證ACI 318-14 設計規範所建議的伸展長度公式是否可適用，並進而建構本土竹節鋼筋之直線伸展長度設計公式。本研究共設計12組握裹試體，鋼筋採用SD420W 材質之竹節鋼筋，混凝土設計抗壓強度為42 MPa和80MPa，研究參數包括鋼筋號數、相對節面積Rr與劈裂指標限制等，並模擬真實梁構件受力情形，採用考慮撓曲應力與剪應力效應之試驗裝置。由試驗結果顯示，不論在普通或高強度混凝土方面，依據ACI 318-14所建議之直線伸展長度設計公式，#8及#10 SD420W竹節鋼筋在美國ACI 408委員會建議之Rr下限值0.1以上均可提供足夠之握裹強度，並建議將Rr下限值下修至0.08，且現行規範適用於竹節鋼筋之劈裂指數上限值2.5有其必要性，以確保握裹性能。本研究之混凝土強度上限值為85MPa，更高強度混凝土之相關試驗，將偕同本研究供後續台灣New RC細部設計參考。 本研究也從國際上蒐集過去文獻之握裹試驗結果，整理成資料庫，一方面與國外學者提出之握裹強度預測公式一一比較精確性，另一方面以資料庫迴歸建立鋼筋混凝土梁之握裹強度預測模型。The bond characteristics of reinforcing steel bars embedded in concrete matrices play a major role in the behavior of reinforced concrete structural members. Bond refers to the interaction between reinforcing steel and the surrounding concrete that allows for transfer of tensile stress from the steel into the concrete. Composite action between concrete and reinforcing bars cannot occur without bond. The relative rib area is one of important factors of reinforcing bar rib geometry affecting bond strength. ACI committee 408 suggested that value of relative rib area is at least 0.10, but no larger than 0.14, in order to ensure bond behavior of reinforced concrete. This paper focuses on a basic issue of bond behavior between SD420W deformed rebar with different relative rib area and ordinary/high-strength concrete. It is one of the most important objectives in this study to verify the suitability of a straight development length proposal by ACI 318-14 code, and then establish a proper design model of straight development length between commercial deformed rebar in Taiwan and ordinary/high-strength concrete. In this study, twelve beam specimens were designed and the study parameters of them include bar size, relative rib area, splitting index. The concrete strength were designed as 42 MPa in ordinary-strength concrete and 80 MPa in high-strength concrete. A bond experiment with beam specimens considering combined effects of moment and shear was conducted. Test results indicated that both ordinary- and high-strength concrete neglecting the limitation of 70 MPa of concrete required by ACI 318-14, the straight development lengths based on the equation of the ACI 318-14 were enough to develop corresponding reinforcement strengths for both reinforcements of #8 and #10 whose value of relative rib area equal and large than 0.8. Nevertheless, the upper limitation of concrete strength was 85MPa. In order to ensure bond behavior required by ACI 318-14, the upper limitation of splitting index equal to 2.5 was essential for specimens with deformed rebar. On the other hand, the study also collected bond tests from international literatures and build data bases, in order to verify accuracy of bond stress prediction models overseas and to build bond stress prediction model for beam test.論文使用權限: 不同意授權鋼筋混凝土握裹應力伸展長度竹節鋼筋相對節面積劈裂指數高強度混凝土握裹試驗reinforced concretebond stressdevelopment lengthdeformed rebarrelative rib areasplitting indexhigh-strength concretebond testthesis10.6342/NTU201602243