Time dependent strain development of early age concrete under step-by-step load history

Abstract With the increasing height of high-rise buildings, adverse effects caused by differential axial shortening become significant. Most of the calculation methods that have been developed to analyze the axial shortening of high-rise buildings are based on a common assumption that creep is linearly proportional to stress and conforms to the superposition principle. However, this assumption is rarely verified when it is used to describe the time-dependent deformation development of early age concrete in construction process. This paper presents an experimental study to examine the validity of this assumption in this use. A step-by-step load was employed to approximately simulate the load history of axial components experienced in the construction process and the strain developments were monitored. A comparative analysis between test results and numerical simulations shows that, the strain development of early age concrete under a step-by-step load is substantially affected by the loading age and stress amplitude, which verifies that the assumption, on which previous methods are based, may lead to inaccurate prediction of strain development in axially loaded concrete components. The time-dependent strain is overestimated with the larger step-by-step stress amplitude and shorter loading history.

[1]  Gilles Pijaudier-Cabot,et al.  Cracking tendency of self-compacting concrete subjected to restrained shrinkage : Experimental study and modeling , 2006 .

[2]  David Lange,et al.  Creep, Shrinkage, and Cracking of Restrained Concrete at Early Age , 2001 .

[3]  M. M. Elnimeiri,et al.  Influence of Column Shortening in Reinforced Concrete and Composite High-Rise Structures , 1989 .

[4]  Comite Euro-International du Beton,et al.  CEB-FIP Model Code 1990 , 1993 .

[5]  Wei-jian Yi,et al.  Dynamic behavior of reinforced concrete frame structure during construction , 2008 .

[6]  N. J. Gardner,et al.  Is Superposition of Creep Strains Valid for Concretes Subjected to Drying Creep , 2004 .

[7]  David P. Thambiratnam,et al.  A numerical method to quantify differential axial shortening in concrete buildings , 2010 .

[8]  Guo Weiliang.  Staged construction analysis and application of mechanical performance on Jingji Commercial Centre , 2010 .

[9]  Liangcai Cai,et al.  Freeze–thaw cycle test and damage mechanics models of alkali-activated slag concrete , 2011 .

[10]  Yan Yao,et al.  A study on creep and drying shrinkage of high performance concrete , 2001 .

[11]  D. Zou,et al.  The influence of sulfate attack on the dynamic properties of concrete column , 2012 .

[12]  W. G. Corley,et al.  Time-Dependent Behavior of Columns in Water Tower Place , 1978 .

[13]  Zdeněk P. Bažant,et al.  Prediction of concrete creep and shrinkage: past, present and future , 2001 .

[14]  Dale P. Bentz,et al.  Mitigation strategies for autogenous shrinkage cracking , 2004 .

[16]  In Hwan Yang,et al.  Prediction of time-dependent effects in concrete structures using early measurement data , 2007 .

[17]  Farid Benboudjema,et al.  Interaction between drying, shrinkage, creep and cracking phenomena in concrete , 2005 .

[18]  David P. Thambiratnam,et al.  Development of a vibration based method to update axial shortening of vertical load bearing elements in reinforced concrete buildings , 2013 .

[19]  D. J. Carreira,et al.  Designing for Effects of Creep and Shrinkage in High-Rise Concrete Buildings , 2007, SP-246: Structural Implications of Shrinkage and Creep of Concrete.

[20]  A. K. Nagpal,et al.  Neural Network for Creep and Shrinkage Deflections in Reinforced Concrete Frames , 2004 .

[21]  K. Kovler,et al.  Prevention of autogenous shrinkage in high-strength concrete by internal curing using wet lightweight aggregates , 2001 .

[22]  Henry G. Russell,et al.  Time Dependent Deformations in a 70 Story Structure , 1971 .

[23]  Ian N. Robertson,et al.  Prediction of vertical deflections for a long-span prestressed concrete bridge structure , 2005 .

[24]  D. Zou,et al.  Influence of creep and drying shrinkage of reinforced concrete shear walls on the axial shortening of high-rise buildings , 2014 .

[25]  B. Persson.  A comparison between mechanical properties of self-compacting concrete and the corresponding properties of normal concrete , 2001 .