By: OWOYEMI J. M.; Tolorunju M. S.;
Abstract:
Large volumes of sawdust are usually generated through sawmilling activities causing environmental pollution.
Finding appropriate use has been a major concern among environmentalists. The use of sawdust inclusion in
producing low-density sandcrete blocks was investigated with sand and sawdust mixture varied in volume to
volume proportion of 80:20 %, 60:40 % and 40:60 % respectively, while cement was kept constant at a mixing
ratio of 1:6, 1:8 and 1:10 respectively. Properties tested include density, water absorption, and volumetric
shrinkage, while the compressive strength of the block was carried out using the compression testing machine
after a curing period of 28 days. The density values obtained showed that 40:60 % sand to sawdust proportion had
the least density of 60 kg/m3
and the highest value was observed for the control level at 210 kg/m3
. The
compressive strengths for the control are 2.8 and 3.5 N/mm2
, which are within the standard values of 2.5 N/mm2
and 3.45 N/mm2
in the Nigeria Industrial Standard (NIS 87, 2000), while 40 to 60 % sand to sawdust mixture
showed 0.8 and 1.1 N/mm2, respectively, which is far below the specified standard, making it suitable for
construction only where lightweight is of utmost importance. A water absorption test carried out after 24 hours of
soaking showed that sandcrete cubes produced without sawdust inclusion had the least absorption of 18.78 %,
while 60 % sawdust inclusion had the highest absorption of 39.0 %. Volumetric swelling indicated that 40:60 %
had the highest value of 11.15 % while the control mix had the least value of 0.12 %. However, based on the
study, 80 % to 20 % and 60 % to 40 % sand and sawdust inclusion met the required standard. Incorporating
sawdust into sandcrete block production in a specified proportion could help to produce light-weight and soundinsulating blocks required for internal partitions in buildings.
Keywords: Sandcrete; building; sawdust; density; Mixing ratio
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