INSTANTANEOUS LOAD-DEFLECTION BEHAVIOUR OF REINFORCED CONCRETE BEAMS

Abstract

Beam deflection under load and concrete cracking is a ubiquitous phenomenon, present in all types of concrete structures. This research work represents a comparative analysis of experimental and theoretical deflections of simply supported beams with different proportions of mild steel as reinforcement and also different curing conditions i.e. Painting, Air and Water curing. Theoretical deflections were measured using AS 3600-2018, ACI 318-14 and Eurocode 2:2004. To differentiate among these codes Shrinkage was kept variable by different curing conditions. Crack width was measured by image processing using ImageJ software and compared with theoretical results using Eurocode 2:2004 and ACI 224.1R-07. Processing of RGB images with sufficient information will provide the parameters of cracks. RGB images were converted into Gray scale proceed by a filtering and thresholding. Crack parameters were automatically determined by Ridge Detection plugin. Deflections of simply supported beams from experimental and calculation results using AS 3600-2018, Eurocode 2:2004 and ACI 318-14 are very close. Image processing is a very effective technique in the study of crack in concrete and for automatic detection “Ridge Detection” plugin is very helpful.