Experimental study on eccentric compressive performance of RC columns strengthened with textile-reinforced high-strength high ductile concrete

Abstract

Textile-reinforced concrete (TRC) exhibits limited efficiency in strengthening RC columns, primarily due to low textile utilization and inadequate compressive strength. To improve the compressive performance of RC columns, high-strength high ductile concrete (HSHDC) is employed to replace the concrete in TRC, forming textile-reinforced HSHDC (TR-HSHDC). HSHDC possesses a compressive strength exceeding 100 MPa and a peak tensile strain of 2 %, with internal short fibers contributing to improved textile utilization. Eight RC columns, including two control columns, one HSHDC-strengthened column, and five TR-HSHDC-strengthened columns, were tested under eccentric loading. The experimental parameters included initial eccentricity, level of preloading, and number of textile layers. The results indicated that the strengthened columns exhibited good integrity at failure and generated fine cracks on the surface. Under non-preloading conditions, the load-bearing capacity and ductility gain caused by TR-HSHDC jackets were from 48.6 % to 181.7 % and 12.1–59.3 %, respectively. As the initial eccentricity increased, the load-bearing capacity gain improved. However, the strengthening effect decreased as the level of preloading increased, which was attributed to the strain lag of the strengthening material. Finally, based on the plane cross-section assumption, a calculation formula considering strain-lag behavior was established to predict the maximum load of the column strengthened with TR-HSHDC.