全尺寸鋼筋輕質混凝土梁之尺寸效應

Size effect of full-size reinforced lightweight concrete beam

張晃維(Huang-Wei Chang)

指導教授 ： 干裕成

朝陽科技大學/理工學院/營建工程系/碩士(2009年)

摘要

國內對於輕質骨材混凝土的結構性能研究，迄今還大部分限於縮小構件尺寸的實驗分析，在輕質骨材混凝土梁方面的結構行為研究也不多見，要進行其結構設計和實務建造應用之前，還需有更多的技術資訊補強相關設計規範，在輕質骨材混凝土梁的承載行為方面，對於輕質骨材混凝土梁的結構行為研究較不多見，且大都為探討其撓曲和剪力之行為與承載力，成果資料還不足以作為制訂規範的依據。
本計畫探討實尺寸輕質骨材混凝土構件之尺寸效應，製造不同尺寸，幾何形狀近似的混凝土梁構件；梁之鋼筋量以最小鋼筋量配置，剪跨與有效深度比為a/d＝3.0，並分三種比例斷面及淨跨長，以中央點載重方式試驗，探討相同邊界條件及載重配置情形下的力學行為及尺寸效應。
研究結果顯示，無剪力筋輕質骨材混凝土梁的延展比，類似常重混凝土者，都隨尺寸的增大而減小，及延展性越差。其中輕質骨材混凝土梁的延展比衰減幅度大於常重混凝土梁者。又無剪力輕質和常重混凝土梁的極限位移比都隨梁尺寸的增大而減小，但輕質骨材混凝土梁的極限位移比衰減幅度明顯大於常重混凝土梁者。

關鍵字

尺寸效應 ； 輕質骨材混凝土

並列摘要

To date, most of research dealing with the behavior of the lightweight reinforced concrete specimens are focus on the laboratory size. It seems valid and necessary to engage on more studies of full size specimen tests, which will lead directly to the design work in practice. This research attempts to provide more information about the flexural and shearing behavior of reinforced lightweight concrete.
The experimental program mainly observes the size effect of reinforced concrete beam. Three-point bending test was performed for identical beam with three different scales in dimension. The beams all designed with minimum reinforcement according for each cross section. The span-to-depth ratios of a/d=3.0, is adopted to investigate the mechanical behavior and size effect.
The test results showed that for a given concrete mixture, the ductility in terms of the ratio of ultimate deflection to yielding deflection decreases with the increase of the scale of the specimen. From the specimen tests, the lightweight concrete behaves stronger ductility decay rather than that of normal concrete. From a dimensionless analysis, it was also observed that the ultimate deflection to span ratio decreases with the increase of the specimen scale, and the ratio for those lightweight concrete beams were greater than those normal concrete beams.

並列關鍵字

size effect ； lightweight concrete

參考文獻

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