A Proposal of Simple Design Equations for Evaluating Flexural Serviceability Performance of Reinforced High and Low Shrinkage HSC Beams

Abstract

The importance of autogenous shrinkage on reinforced high-strength concrete (HSC) flexural beams' serviceability performance, as well as effectiveness of low-shrinkage HSCs (LS-HSCs) made with a Belite-rich low heat portland cement and/or expansive additive and/or shrinkage-reducing chemical agent with regard to beam flexural serviceability performance improvement, is shown in this paper. This paper additionally uses a simple design equation point of view to propose a new reinforced concrete beam flexural crack width and deformation evaluation concept. HSC autogenous shrinkage is shown, through experimental results, to significantly increase RC beam crack width and deformation while serviceability performance was markedly improved through LS-HSCs. Taking tension reinforcement strain change and cracked section curvature change before and after loading into account, the present concept is effective in explaining concrete shrinkage and expansion effects before flexural deformation and maximum crack width loading. Japan Society of Civil Engineers code equations for maximum flexural deformation and crack width prediction which incorporate the present concept improve the accuracy of prediction in comparison with conventional ones and show fairly good experimental result agreement.