Mortar with wood waste ash: Mechanical strength carbonation resistance and ASR expansion

•Timber processing waste is source of fuel resulting in ash which is assessed for partial cement replacement.•No workability loss was observed sparing use of superplasticizer in future concrete production.•No strength loss was observed for up to 20% cement replacement levels.•Improvement of up to 60% reduction in expansion due to ASR was observed.•SEM on reactive particles after ASR attack showed surface grooving and gel layer formation. Portland cement production is an energy-intensive industry, responsible for about 5% of the global anthropogenic carbon dioxide emissions worldwide. An important contribution to sustainability of concrete and cement industries consists of using pozzolanic additions, especially if obtained from waste. Timber processing waste is a sustainable and renewable source of fuel for energy production. However significant amounts of wood waste ash are created from the thermal conversion of wood waste and if not managed properly, may result in serious environmental and health problems. Wood waste ash (WWA) was used in mortar as a partial cement replacement (0%, 10% and 20%) material to ascertain applicability in concrete. An extensive experimental program was carried out on mortar containing WWA to assess strength and durability parameters (Carbonation and ASR). Enhanced strength and durability results confirmed that wood waste ash can further contribute to sustainability in construction.