Effect of Saw Dust Ash and Rice Husk Ash on some Geotechnical Properties of Makurdi Burnt Clay Bricks

The use of cheap and waste materials in bricks production have been encouraged as an alternative to industrial stabilizers due to high cost of cement or lime for production of stabilized bricks. This study looks at the potential of using wastes like saw dust ash (SDA) and rice husk ash (RHA) mixture in treatment of Makurdi clay for burnt bricks production and its subsequent assessment for structural building bricks. Makurdi clay was treated with SDA and RHA mixture, each at 0%, 2%, 4% and 6% respectively. The compressive strength of the burnt bricks increased from 9.40 MN/  for untreated brick to a maximum value of 11.29 MN/  for 2%SDA+2%RHA treated burnt bricks. Treatment with waste mixtures above this content resulted in decreased strength. The water absorption of 14.9% for untreated burnt brick increased to a value of 16.2 % for 2%SDA+2% RHA treated burnt brick. Treatment with higher waste mixture additions resulted in increased water absorption up to 19.4% for 6%SDA+6% RHA treated burnt brick. Energy Dispersion X-ray Spectrometer results showed the presence of calcium, silicate and aluminate as a cementitious compound in the 2%SDA+2%RHA treated burnt brick. The compressive strength value of 11.29 MN/  is greater than 10.3 MN/  which is the minimum value suitable for structural building bricks in grade negligible weather based on ASTM C62-99. Thus 2%SDA+2%RHA treated burnt brick from Makurdi clay is recommended for structural building bricks in grade negligible weather