Finger joints and their structural performance in different exposure conditions

Abstract

Timber is widely used as a construction material in Sri Lanka for different application. Finger joint is one of the efficient method to minimize the timber wastages arising in the timber industry. In this study main objectives are to determine the best combination of timber materials for timber joints in different environmental conditions as well as their structural performance. Seven locally available timber species Mahohany, Kumbuk, Grandis, Teak, Jack, Banyan and Pinus were selected for the study. The physical properties (shrinkage and swelling) related to moisture content were investigated in different environment condition by using temperature and humidity chamber to choose best combination of timber materials. In addition different strength tests bending and tension were conducted for those selected combinations. Average moisture contents of timber specimens were around 12%.In wet condition all the samples shows increase in moisture content as well as volume. Modulus of elasticity varies 800 MPa - 2200MPa, modulus of rupture varies 10 MPa – 22 MPa, Similarly other test parameters were investigated and presented in the paper.