IS 1708 : Part 1 to 18 : 1986 : Methods of testing of small clear specimens of timber

0. FOREWORD

0.1 This Indian Standard ( Second Revision) was adopted by the Indian Standards Institution on 30 April 1986, after the draft finalized by the Timber Sectional Committee had been approved by the Civil Engineering Division Council.

0.2 The evaluation of basic properties of timber, such as strength, density effect of various treatments on strength, etc, and the establishment of design functions for structural timbers has been done on the basis of tests carried out on small clear specimens of timber. A clear specimen is one which is free from defects, such as knots and shakes. The comparison of strength properties of different timber species is also done on the basis of the tests carried out on clear specimens. In the actual design of timber structures as also in structural grading, the effect of different kinds of defects on clear specimens is assessed and after making necessary allowances for the defects, the resultant values are used. This standard is being published in parts dealing with the methods of testing small clear specimens of timber for their strength properties.

0.3 In order to obtain a good average figure, which is truly representative of the species, it is necessary to take samples from green timber as well as from seasoned timber and also from sapwood, heartwood and from different parts of the same tree. For standard evaluation of physical and mechanical properties of a species from a locality, at least ten trees are chosen at random from the locality and sampling of material for different test is one in accordance with IS : 2455-1974*. When material from a depot is required to be tested, the sampling of material for different tests is done in accordance with IS : 8720-l978t.