The Properties of Concrete Utilizing Partial Aggregate Replacement with Locally Sourced Mediterranean Agro-Waste

The growth of the global population has led to increased demand for agricultural products, resulting in greater agricultural waste production. One sustainable response to this challenge is using agricultural waste as raw material in building materials. This study examines the potential for partial replacement of natural aggregates in concrete with agricultural waste from typical Mediterranean fruits: sour cherry pits, grape seeds, ground olive pits, and carob seeds. To evaluate the effect of treatment on the behavior of agro-waste aggregates, ground olive pits were used untreated, treated with ash water, or treated with seawater. Carob seed concrete deteriorated during water curing due to seed swelling and tannin-related degradation, revealing its unsuitability without prior stabilization. Partial replacement of natural aggregates with agricultural waste resulted in decreased density, ultrasonic pulse velocity (UPV), dynamic elastic modulus, compressive strength, and thermal conductivity, while increasing saturated water absorption. Treatment with ash water on ground olive pits improved the interfacial transition zone (ITZ), resulting in 29% increase in compressive strength relative to untreated ground olive pits. Concrete with ash water treated ground olive pits demonstrated the highest practical potential among all tested agro-waste concretes.