EFFECT OF FRP STRENGTHENING ON FLEXURAL CAPACITY OF PRECAST U-DITCH CHANNEL

The precast channel system (U-Ditch) is one of the innovations of precast concrete designated as a channel for drainage and irrigation systems. The U-Ditch must have sufficient bending capacity to carry a major load due to ground pressure. However, the addition of wall thickness will lead to the heavy construction product. Therefore, a new product innovation was developed in this study, where the wall thickness was reduced and strengthened using fiber reinforced polymer (FRP). In these regards, this study aims to investigate the effect of FRP strengthening on the behavior of precast channel systems. Three types of specimens were tested in this study. Type N was normal U-ditch which without a reduction of wall thickness. Type C was U-ditch with a reduction of wall thickness (corrugate). Type CF was U-ditch with a reduction of wall thickness (corrugate) and strengthened using fiber reinforced polymer (FRP). The dimension of all specimens was 500x500x1000 mm3 . The specimens were tested based on Japan Industrial Standard (JIS). The results indicated that the weight reduction can be achieved by reducing the wall thickness in the area between the main reinforcement. However, it reduced the bending capacity of the wall. The strengthening using FRP sheet in the thickness reduction section was effectively to increase the bending capacity of wall, which had relatively the same with Type N (normal). Finally, all the specimens failed due to the flexural cracks around hook area of the precast channel.