THE JOURNAL OF KMUTNB

Volume 32, No. 04, Month OCTOBER, Year 2022, Pages 879 - 890

Torsional strengthening of damaged low-strength rc beams using prestressed ductile metal straps

Katipoj Sanupong, Weerasit Chamnankit, Komsan Dangyem, Thanongsak Imjai

Abstract Download PDF

This research deals with the efficiency of torsional strengthening system on damaged low-strength reinforced concrete (RC) beams using post-tensioned metal strapping (PTMS) technique on 2-phase experiment. In phase 1, the test focused only on the first crack to determine the significant increase of torsional strength. In phase 2, all pre-cracked beam specimens from phase 1 were repaired with non-shrink cement and confined with high-ductile metal straps. To simulate the damage building, all strengthening beams were subsequently re-tested under pure torsion in the laboratory. Based on the test results, it is found that the use of the PTMS technique significantly enhances the torsional capacity. It is also found that the use of non-shrink cement as a crack repairing material for damaged concrete beams increased only the ultimate torsion capacity of the strengthening beams by up to 33%.

Keywords

Torsion; Low-strength Concrete; Post-tensioned Metal Strapping; Strengthening; Metal Straps; Cracks

---