Axial compressive behaviour of concrete confined with polymer grid
This study presents results of an experimental investigation on the axial compressive behaviour of concrete confined with polymer grid. A total of 14 concrete specimens with 150 mm diameter and 300 mm height were prepared and tested under axial compression. Two types (Type A and Type B) of polymer grid with different mechanical properties were selected. Type A polymer grid (36 mm x 36 mm) was manufactured from polypropylene fibres, while Type B polymer grid (36 mm x 24 mm) was manufactured from high modulus polyester fibres. For each type of polymer grid, one layer, two layers, and three layers were used to investigate the influence of the amount of polymer grid confinement on the axial compressive behaviour of concrete specimens. The test results show that concrete specimens confined with polymer grid obtained much higher deformation capacity than unconfined concrete specimens, although the improvement in the strength was not highly significant. Type A polymer grid performed better in improving the strength and deformation capacity of concrete specimens than Type B polymer grid. The test results indicate that polymer grid can be used as a secondary confinement reinforcement for concrete specimens. Based on the analysis of test results in this study as well as test results from previous studies, an empirical model for the polymer grid confined concrete was developed. The developed empirical model predicts the peak strength, axial strain at peak strength, strength at ultimate strain, and ultimate strain of polymer grid confined concrete with good accuracy.