預鑄梁與場鑄樓版間之混凝土冷縫界面對T型梁耐震行為影響

The Effect of the Construction Joint Created between Precast Beam and Cast-in-Place Slab on the Seismic Behavior of Reinforced Concrete T-Beams

王勇智(Yung-Chih Wang) ； 鄭智仁(Jhih-Ren Jheng)

《結構工程》 29卷4期 (2014/12) Pp. 45-64

https://doi.org/10.6849/SE.201412_29(4).0003

摘要

本實驗主要是針對T型懸臂梁進行耐震行為分析，乃利用有或無預鑄施工冷縫T型梁，針對不同剪力跨度（a/d=2.44與a/d=5.46）進行討論。一般冷縫界面剪應力檢核之經驗公式由單向荷載實驗得來，並未探討其在反覆地震力作用下是否適用，這也是本文研究目的。由實驗結果得知，有預鑄施工冷縫的T型短梁比一體澆置試體更易發生冷縫界面滑移。當剪力跨度越長，其抵抗滑移的面積越大，就越不易發生冷縫界面滑移。於負彎矩受力時，版筋受拉之有效版寬貢獻，有預鑄施工冷縫的T型短梁為一體澆置試體的1.4倍。另外，由T型短梁冷縫界面剪應力分析結果得知，當量測之冷縫界面滑移量達0.5mm時，平均界面剪應力則達0.2f''''_c，與一般規範經驗公式上限值相當，應可作為冷縫界面剪應力耐震檢核標準。

關鍵字

施工冷縫 ； 界面剪應力 ； T型斷面梁 ； 耐震行為

並列摘要

The purpose of the experimental study is to observe the seismic behavior of T-shaped cantilever beams. The study investigates the effect of construction joint and shear span (a/d=2.44 and a/d=5.46), and verifies the current design equations obtained from monotonic loading experience for evaluating interface shear stress. The test results indicate that the T-shaped short beam with construction joint slipped more obviously at the interface than the beam without construction joint. According to test results, in the negative moment when the slab bars stress in tension, the effective width of T-beam flange with construction joint is 1.4 time wider than the beam without construction joint. In the comparison between slender beams and short beams it was found that slender beams had less cold-joint slip effect than short beams. This is because the area of shear resistance at interface for slender beams is larger than short beams.

並列關鍵字

Construction Joint ； Interface Shear Stress ； T-Beams ； Seismic Behavior