Valorization of Wood Ashes as Partial Replacement of Portland Cement: Mechanical Performance and Durability

The study presents the behaviour of wood ash / OPC mortar. Two wood ashes are used in this study WA1 and WA2. Chemical analysis of wood ash, bulk density, sieve analysis and specific gravity of wood ash and aggregates, loss on ignition (LOI), X-ray diffraction (XRD) analysis and infrared spectrometry (IR)analysis of wood ash, consistency and setting time of the fresh paste, durability test and density of mortar cubes were conducted to determine the suitability of the materials for mortar making. Percentage replacement level of 0, 5, 10, 15, 20, and 25 percents of cement by wood ash were used. 40×40×40mm cubes were cast, cured and crushed at 7, 28 and 56 days to determine their compressive strength. Test result indicates that the WA1 is slightly pozzolanic, WA2 not. Water demand increases as the ash content increases and the setting time of the paste increases as the ash content increases. Compressive strength of wood ash / OPC concrete it increases with age at curing with optimum replacement of cement by WA1 of 15%. Density and durability increases as the ash content increases.