Open AccessAssessment of Strength Compliance with Standards for Tanzania Eucalyptus Wood Poles Treated with Copper-Chromium-Arsenic Compounds
Author(s) -
Alex Lyatonga Mrema
Publication year - 2007
Publication title -
tanzania journal of engineering and technology/tanzania journal of engeering and technology
Language(s) - English
Resource type - Journals
eISSN - 1821-536X
pISSN - 2619-8789
DOI - 10.52339/tjet.v30i2.404
Subject(s) - arsenic , tanzania , chromium , eucalyptus , young's modulus , materials science , environmental science , metallurgy , composite material , biology , ecology , environmental planning
Samples of copper-chromium arsenic compounds (CCA) treated Eucalyptus poles for power transmission were sampledfrom a lot following Military Standard MIL-STD 105D, Single sampling, Tightened Inspection, Acceptable Quality Level(AQL) of 4 as provided for in the South African Standard SABS 754:1994 from lots containing 151-500 poles. Sampleswere randomly selected from a lot. Maximum fiber stresses were evaluated taking into account the actual taper in eachpole. The cantilever loading test was performed on the samples following SABS 754:1994. It was found out that theaverage taper for the poles was smaller than that assumed in the standard due to the different pole growthcharacteristics and environment in Tanzania and that the average modulus of elasticity obtained for the poles was lowerthan the average assumed in SABS 754:1994. The poles also showed excessive deflections at working loads. It isrecommended to the Tanzania Bureau of Standards that although SABS 754:1994 is meant to be used for eucalyptuspoles grown in Southern Africa south of the Sahara that are treated with creosote or CCA there is a need to review it totake into account the actual characteristics of the poles grown in Tanzania where they are normally grown in highlandareas with higher rainfall and colder climates.