High-performance eco-concrete beams with calcined montmorillonite, metakaolin pyrolyzed coffee grounds, and hybrid fibers for enhanced bending strength and microstructural refinement. - Hepautwa, Amani Abdallah; Hilonga, Askwar; Mrosso, Register; Alfredy, Tusekile; Mwalusambo, Gabriel; Lesafi, Fina; Chande Jande, Yusufu Abeid (PLoS ONE, 2026)