Abstract:
effectiveness of three conventional practices to enhance the compressive strength of reinforced concrete columns in Thailand was presented in this study. Three column strengthening techniques widely used in Thailand namely as Reinforced Comcrete Jacketing (RCJ), Non-shrinkage Concrete Jacketing (NS), and Carbon Fiber Reinforced Paper (F) were investigated through laboratory experiments. Five reinforced concrete specimen columns with a dimension of 15x15, 20x20, and 25x25 cm. and 40 cm. in heights were casted. After curing of 28 days, four of each specimen dimension were strengthened by RCJ, NS, F1 and F2 techniques,respectively. The results show that the columns strengthened by RCJ, F1 and F2 and F2 have compressive force increased comparing to the control specimens. The NS cilumns, on the other hand, show an insignificant increasing of a compressive strength for all specimen dimensions. This indicates unsuccessful improvement of the compressive force by using the Non-shrinkage Concrete Jacketing technique with the details of four main reinforcing bars at the corners and wrapping around with the low-strength wire mesh. All techniques can also improve the deformation of columns, except the Non-shrinkage Concrete Jacketing.Therefore, it can conclude that Reinforced Concrete Jacketing and Carbon Fiber Reinforced Paper techniques can increase the compressive strengths of reinforced concrete columns. In contrast, Non-shrinkage Concrete Jacketing techniques is not only ineffective for increasing of the column strength but also no use for improving of the column deformation. It should not be recommended in constructions unless it has a further study on the detaols of reinforcements.