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Research Journal of the University of Ruhuna, Sri Lanka- Rohana 11, 2019

Reliability testing on finger jointed timber according to the standard experimental

procedures reveal that,

• Satin, Teak and Pine timber which have minimum bending strength reduction as
9.5%, 10.84% and 19.43 % respectively compared to clear timber are effective

to manufacture finger jointed timber element to withstand bending. Bending

strength was varied as; Satin>Teak>Pine>Mahogany>Grandis>Jak>Kumbuk
• Compressive strength parallel to grain reduction was found to be only 1.53% of

that of clear specimens for Jak and therefore it is the most suitable species to use
for finger joining. Satin, Grandis and Pine also have 13.24%, 13.22% and 3.04%

strength reduction which are also suitable for withstand compression parallel to
grain after Jak. Compressive strength parallel to grain was varied as was varied

as; Jak>Pine>Grandis>Satin>Mahogany>Teak>Kumbuk

• Compressive strength perpendicular to grain values were found to be higher than
clear timber other than Jak. Higher increment is shown by Teak and Pine as

18.13% and 27.39% that of clear timber. Compressive strength perpendicular to

grain was varied as was varied as; Pine>Teak>Satin>Kumbuk>Grandis>
Mahogany>Jak.

• Reliability testing of finger jointed large scale timber which was done by using
1000 mm×100mm×100mm structural scale members of Grandis and Pine

resulted 72.58% and 80.29% reduction of ultimate compression capacity

compared to clear timber. It was led to think that finger joint large scale timber
members are poor to withstand axial compression and several number of finger

joints are not effective for compression member.
The primary goal of this research is to utilize the timber waste considering the

applications in construction industry. For that, below recommendations are done and

it could increase the use of finger joint on waste timber.

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