Instantaneous deflection of light-weight concrete slabs

Construction loading before the age of 28 d can have the most significant effects on the slabs, especially for multi-story structures. The changing properties of the young concrete complicate the prediction of serviceability design requirements also. An experimental investigation is performed on four simply supported Light-Weight Concrete (LWC) one-way slabs subjected to immediate loading at 14 d. Effects of aggregate type, loading levels and cracking moment together with the influences of ultimate moment capacity and service moment on the instantaneous deflection of slabs are studied. Comparison of the obtained results with predictions of existing models in the literature shows considerable differences between the recorded and estimated instantaneous deflection of LWC slabs. Based on sensitivity analysis of the effective parameters, a new equation is proposed and verified to predict the instantaneous deflection of LWC slabs subjected to loading at the age of 14 d.

[1]  Mehmet Gesoğlu,et al.  Fresh properties of self-compacting cold bonded fly ash lightweight aggregate concrete with different mineral admixtures , 2012 .

[2]  Amin Ghali,et al.  Long-term deflection prediction of concrete members reinforced with glass fibre reinforced polymer bars , 2000 .

[3]  Andrew Scanlon,et al.  Shrinkage Restraint and Loading History Effects on Deflections of Flexural Members , 2008 .

[4]  Peter H. Bischoff,et al.  Equivalent Moment of Inertia Based on Integration of Curvature , 2011 .

[5]  B. Benmokrane,et al.  Flexural response of concrete beams reinforced with FRP reinforcing bars , 1996 .

[6]  Shami Nejadi,et al.  Mix design of light-weight self-compacting concrete , 2016 .

[7]  C. Mazzotti,et al.  Long-Term Deflection of Reinforced Self-Consolidating Concrete Beams , 2009 .

[8]  P. Bischoff.  Deflection Calculation of FRP Reinforced Concrete Beams Based on Modifications to the Existing Branson Equation , 2007 .

[9]  Jinxia Xu,et al.  Mechanical properties of expanded polystyrene lightweight aggregate concrete and brick , 2012 .

[10]  Behnam Vakhshouri.  Time-dependent bond transfer length under pure tension in one way slabs , 2016 .

[11]  Ali Nadjai,et al.  Aspects of behaviour of CFRP reinforced concrete beams in bending , 2008 .

[12]  Cledwyn Thomas,et al.  Development of a Model for the Effective Moment of Inertia of One-Way Reinforced Concrete Elements , 1998 .

[13]  Yue Li,et al.  Properties of lightweight concrete composed of magnesia phosphate cement and expanded polystyrene aggregates , 2015 .

[14]  David W. Dinehart,et al.  Effective Moment of Inertia for Glass Fiber-Reinforced Polymer-Reinforced Concrete Beams , 2003 .

[15]  Peter H. Bischoff,et al.  Tension stiffening and cracking of concrete reinforced with glass fiber reinforced polymer (GFRP) bars , 2004 .

[16]  Tarek H. Almusallam,et al.  Performance of glass fiber reinforced plastic bars as a reinforcing material for concrete structures , 2000 .

[17]  Cj Burgoyne,et al.  Moment-Curvature and Strain Energy of Beams with External Fiber-Reinforced Polymer Reinforcement , 2009 .

[18]  Şemsi Yazıcı,et al.  Self-compacting lightweight aggregate concrete: design and experimental study , 2009 .

[19]  S. H. Mirmoradi,et al.  The effect of polypropylene fibers on the properties of fresh and hardened lightweight self-compacting concrete , 2011 .

[20]  R. Al-zaid,et al.  Effect of Reinforcement Ratio on the Effective Moment of Inertia of Reinforced Concrete Beams , 1993 .

[21]  R. F. Zollo,et al.  Fracture Properties of Concrete Containing Expanded Polystyrene Aggregate Replacement , 2013 .