Behavior of slender uPVC-confined concrete columns under applied load

Abstract

The concept of a novel tubular column supporting system for front porch in buildings is introduced in the present study. The tabular system has large flexibility, economic advantages, and can maintain the integrity of the structure. It consists of unplasticized polyvinyl chloride tubes with infill made of conventional concrete (UPC) reinforced with minimum steel rebar. The compression behavior of the individual columns was examined by conducting laboratory tests UPC members under concentric axial load. Various slenderness ratio was used to quantify the effect of tube and tube geometry on the structural behavior of the specimens. Test results show that the structural performance of the UPC members was sensitive to the length effect, displaying a captivating interplay of material properties with considerable post yielding deformation. The experimental test results were compared with the predicted bearing capacities using the European EC4, American specification AISC 360 − 16, and Australian/New Zealand standard AS/NZS5100 (AS/NZS) design codes. All the three codes under-estimated the strength of UPC specimens. The EC4 and AISC360-10 codes give the closest predictions, in contrast to AS/NZS 5100 which give more conservative predictions. Therefore, the current specifications for steel cannot be directly used to size UPC compress-ion members. Based on the Euro-code design requirements and material characteristics of uPVC-concrete, a strength model is proposed using a comprehensive database of 491 tests compiled from the results of the present study and the relevant literature.