鋼筋混凝土托架之剪力強度

Shear Strength of Reinforced Concrete Corbels

本研究對 24 個剪力跨度與有效深度比大於1 之鋼筋混凝土托架試體進行試驗。試驗結果顯示，剪力跨度與有效深度比愈小之托架，其剪力強度愈高。試驗結果亦顯示，混凝土抗壓強度愈高及垂直剪力鋼筋參數愈高之托架，其剪力強度也愈高。本文亦建議了一個剪力跨度與有效深度比大於1 之托架剪力強度分析方法。經由試驗結果與分析值之比較得知，對於剪力跨度與有效深度比大於1 之托架，本文所建議之分析方法及ACI 規範之壓拉桿模型皆能合理地預測其剪力強度。惟相較於ACI 規範之壓拉桿模型，本文所建議之分析方法則能更為精確地預測a d >1 托架之剪力強度。

In this study, 24 reinforced concrete corbels with shear span-to-depth ratios greater than unity were tested. Test results indicate that the lower the shear span-to-depth ratio, the higher the shear strength of the corbel. Furthermore, the higher the compressive strength of concrete and the vertical stirrup parameter, the higher the shear strength of the corbel. An analytical model for determining the shear strength of reinforced concrete corbels with shear span-to-depth ratio greater than unity is also proposed in this paper. The shear strengths predicted by both the proposed method and the strut-and-tie model of the ACI Code are compared with the test results. The comparison shows that both the proposed method and the strut-and-tie model of the ACI Code can reasonably predict the shear strengths of reinforced concrete corbels with shear span-to-depth ratio greater than unity. For reinforced concrete corbels with shear span-to-depth ratio greater than unity, the comparison also shows that the proposed method can more accurately predict the shear strength than the approach of ACI Code.