Improving Tensile Strength Characteristics and Water Absorption of Laterite Interlocking Blocks Enhanced with Different Burnt Sawdust Ash from Timber Species

Laterite interlocking blocks are usually compressed with cementing materials, Burnt Sawdust Ash (BSDA) to improve their performance properties for construction purpose. The study aimed to partially replace ordinary Portland cement (oPc) with burnt sawdust ash (BSDA) from timber species (Wawa, Mansonia, Teak, Odum, Ceiba, Essah and Mahogany) in making interlocking laterite blocks by replacing 0-30 wt %. Mix proportion was 1:6 (cement + BSDA: laterite) with a 0.60 water-to-cement ratio. 330 specimens of size 185 mm × 220 mm × 120 mm were produced and cured at normal temperature and humidity under shady and sunny conditions for 7, 14, 21 and 28 days. Three (3) tests were research targeted: density, tensile strength and water absorption. However, it was observed 10% Wawa and ceiba have relative good density properties and mansonia and ceiba have better water absorption properties. It was observed that, up to 10% of Mansonia, Wawa (Triplochiton scleroxylon) and Odum (Milicia excels) BSDA have the potential to perfectly substitute cement in the production of interlocking blocks in terms of tensile strength.