Valorization of Olive Stone in Cement Mortars for Harmonized Applications

Nowadays construction sector continues to face major environmental challenges, largely due to the consumption of natural resources, energy, and water, as well as the generation of waste and emissions into the environment. In Andalusia (Spain), the olive oil industry plays a central role in the economy, generating large volumes of waste and by-products, including olive stones. Due to their physical characteristics, olive stones represent a potential substitute for conventional aggregates in cement mortars, which are not subjected to restrictive technical standards as concrete. This study evaluates the technical feasibility of cement mortars prepared by replacing 10% and 20% of conventional sand (by volume) with four different types of olive stones. Tests were carried out on setting times, consistency, density, and air content, in fresh state, as well as on capillarity, density, and flexural and compressive strengths, in hardened state, using a conventional mortar as reference, with favorable results. Mortars could be classified according to the harmonized standards for masonry, rendering and plastering, and flooring and screed mortars, and for the applications described in the Spanish Building Code (CTE). This progress in knowledge would further support the integration of the construction sector into the fields of sustainability and circular economy.