輕質骨材鋼筋混凝土梁之曲率韌性、剪力強度之研究

Curvature Ductility and Shear Strength of Lightweight Concrete Beam

林文山(Wen-Shan Lin) ； 高健章(Chen-Chang Kao)

《中國土木水利工程學刊》 20卷4期 (2008/12) Pp. 469-482

https://doi.org/10.6652/JoCICHE.200812_20(4).0002

摘要

本文利用輕質骨材混凝土應力－應變曲線，對其撓曲強度之等值應力塊、斷面曲率韌性及剪力強度進行研究。輕質骨材混凝土與常重混凝土之應力－應變曲線不同，因此，本文首先蒐集彙整有關實驗資料，決定輕質骨材混凝土之應力－應變曲線，作為後續研究撓曲強度之等值應力塊及斷面曲率韌性之基礎，利用力學原理檢討現行規範對於輕質骨材混凝土撓曲強度之等值應力塊之適用性，並由曲率延展比之理論推導、統計迴歸出拉力鋼筋比、壓力鋼筋比和混凝土強度與曲率韌性比之公式，並將製成圖表，提供設計者在不同曲率韌性需求下之鋼筋配筋方式，以補充耐震設計規範中，僅限制鋼筋比而無法得知相對應的曲率韌性之缺點。最後利用ACI318-99、ACI318-02、軟化壓拉桿及軟化壓拉桿－簡算法四種評估方法，評估輕質及常重鋼筋混凝土梁之剪力強度，並比較其差異性。

關鍵字

輕質骨材混凝土 ； 曲率韌性 ； 剪力強度 ； 壓拉桿模式

並列摘要

Equivalent stress block, curvature ductility, and shear strength for lightweight concrete beam was investigated. These studies must determine stress-strain curve first. Since the stress-strain curve of lightweight concrete is different from normal weight concrete, the above-mentioned properties will be change. This paper collects the stress-strain curve for lightweight concrete, and using these data to modify or check equivalent stress block of calculating flexural strength in RC design code. The curvature ductility ratio was obtains to express formula and table by using basic RC theory. These tables and formulas provide amount of steel bar under curvature ductility. Finally, the paper presents evaluation on shear strength of lightweight concrete beams using ACI 318-99, ACI318-02, softened strut-and-tie model and simply softened strut-and-tie model. Comparing calculated shear strength with experimental data reported in previous literature examined the different evaluation method.

並列關鍵字

lightweight concrete ； curvature ductility ； shear strength ； strut-and tie model