Effect of lime and wood biomass ash on the compressive behaviour of a clayey soil: A comparative study

The amount of biomass ash generated worldwide is supposed to increase in the near future and therefore a huge amount of ash should be properly handled, giving added value to the waste and avoiding its landfilling. Due to its pozzolanic properties, the use of wood biomass ash (WBA) in the construction of road pavement is an attractive solution to reduce carbon emissions and address the shortage of fossil fuels. In this study, WBA and lime have been used as stabilizing agents of a clayey soil, whose compressive behaviours has been investigated in the short- and long-term. The design percentage of each stabilizer into the mixture has been set based on pH value. The compressive performance has been analyzed in terms of both unconfined compressive strength and tangent modulus by applying an asymptotic regression model. Results highlight comparable compressive performance among studied mixtures, with faster effect of curing on WBA blends.