KEMPAS TIMBER UN-BONDED POSTTENSIONING SOLUTION NEW APPROACH

Post-tensioning technique is a commonly used for concrete structure. This technique had many advantage, it gives thinner section larger span, better cracking resisting sections. For timber material it is a new technique with limited use. in this paper a natural timber (Malaysian Kempas type) is used in post-tensioning solution. Two methods are investigated for post-tensioning solution. The first method is the standard method of post-tensioning which used commonly in concrete pre-stressing that include pump and jack tools. The other method is a new way for post-tensioning that depending on the fundamentals of pre-stressing and bending theory. Two type of threaded rod bar are used. The two methods were deflection control process and the post-tensioning force estimated by stress-strain relation. The limitation of posttensioning force was depending on the timber, rod bar strength capacity. The results clear that standard method is more effective in post-tensioning process while the posttensioning by bending is safer for specimens due to avoiding stress concentration at the end face of beam.