Study on the potential of using HPFRC as a repair material for concrete damaged RC short columns

Abstract

This paper contains the experimental studied on the effectiveness of using high performance fiber reinforced concrete (HPFRC) to repair square and circular concrete damaged RC short columns. Two different cross sectional shapes of the reinforced concrete columns were considered. Ten reinforced concrete columns were prepared as a normal strength concrete (NSC) and the columns were identify into three categories which are; a) columns without subjected to damaged, b) concrete damaged columns and c) concrete damaged columns repaired with HPFRC. All four sides of the damaged columns were strengthened by three different HPFRC jacketing thicknesses which are 10mm, 20mm and 30mm. All column samples were tested under axial load by using compression machine to obtain columns crack load and the crack pattern of the samples. The laboratory result indicates that the crack load of concrete damaged column repaired with HPFRC was significant affected by the column cross sectional shape and HPFRC jacketing thickness. The HPFRC 10mm, 20mm and 30mm jacketing thickness repaired on damaged square columns significantly increases the crack load about 9.9%, 37% and 57.8% respectively as compared to the undamaged of square columns. On the other hand, repaired damaged circular columns with HPFRC 10mm, 20mm and 30mm increases the crack load of about 38%, 64.6% and 96% respectively as compared to the undamaged circular columns. The crack load increase as the jacketing thickness increases due to higher confinement effect. It shows that repaired damaged circular column was more prominent than repaired damaged square column.