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Optimal determination of the cover of concrete beam under multi-environmental conditions



Title: Optimal determination of the cover of concrete beam under multi-environmental conditions
Author(s): C. Lu, W. Jin
Paper category : conference
Book title: The 50-year Teaching and Research Anniversary of Prof. Sun Wei on Advances in Civil Engineering Materials
Editor(s): C. Miao, G. Ye and H. Chen
Print-ISBN: 978-2-35158-098-1
e-ISBN: 978-2-35158-099-8
Publisher: RILEM Publications SARL
Publication year: 2010
Pages: 209 - 221
Total Pages: 13
Nb references: 24
Language: English


Abstract: In order to determine the cover thickness of reinforced concrete beam reasonably, three different conditions, including structural durability, limitation of crack width and fire resistance, are took into account here. Firstly, to the durability problems, two aggressive issues about concrete carbonation and chloride attack are discussed. And based on Monte Carlo simulation method, the beam’s minimum concrete covers, at certain design service life, are proposed with 95% reliability probability. Secondly, three crack width formulas got from our national code GB50010, American Concrete Institute (ACI) Committee 318 and Eurocode2 are used to compute the crack width values for a same simple-supported beam, and the maximum cover thicknesses are obtained under the specified crack width limitations.
Thirdly, to study the fire resistance of concrete beam, the software COMSOL 3.3 is adopted to simulate the time-dependent temperature distribution in beam with the International Standard Temperature-rising Curve. And combining the high-temperature degeneration relations of materials’ mechanical properties, the beam’s minimum cover requirements are determined under certain anti-fire carrying capacity limitation. At last, based on above results, the optimal cover values of concrete beams are proposed for different design service life and they are compared with the requirements in GB50010, ACI318 and Eurocode2. The comparative results show that our proposed values are more rational than that of GB50010, and close to the values proposed in ACI318 and Enrocode2. So, relevant analytical results are credible and can provide some reference to structural designers and code constitutors.


Online publication: 2010-04-22
Publication type : full_text
Public price (Euros): 0.00