Systematic Review of Coffee and Rice Ash in Physical-Mechanical Properties and Concrete Durability

Abstract

Concrete is one of the most widely used building materials worldwide, but its production generates a high carbon footprint due to the high clinker content in Portland cement. In response, coffee husk ash (CCC) and rice husk ash (CCA) are being investigated as sustainable alternatives to partially replace cement. This paper presents a systematic review of recent studies in Scopus and ScienceDirect, applying selection criteria related to technical relevance, availability of experimental results and incorporation of both ashes in concrete and mortar mixtures. Likewise, a bibliometric analysis is developed using VOSviewer to identify research trends, countries, outstanding authors and predominant keywords. The compiled studies allow us to compare the effect of CCC and CCA on physical properties (workability, density, absorption), mechanical properties (compressive strength, tensile strength and bending) and durability (permeability and resistance to chlorides and sulfates). Overall, the evidence shows that both ashes can be used as supplementary cementitious materials in moderate replacements, valorizing agro-industrial waste and reducing the environmental impact of the concrete, as long as parameters such as fineness, calcination conditions and dosage are controlled to guarantee optimal and sustainable results