Sustainable and Green Building Materials: Performance and Embodied Carbon of Low-Clinker Binder Systems

Abstract

The production of ordinary Portland cement is a major contributor toanthropogenic carbon dioxide emissions, and the construction sector istherefore under increasing pressure to adopt lower-carbon material systems. This paper examines the mechanical performance and embodied carbon of concrete produced with partial and full replacement of clinker bysupplementary cementitious materials. Mixes incorporating fly ash andground granulated blast-furnace slag at several replacement levels werecompared with a control mix, together with an alkali-activated geopolymerbinder. Compressive and flexural strength were evaluated alongside anestimate of embodied carbon per unit volume. The results show that moderate replacement levels retain acceptable strength while reducing embodied carbon appreciably, and that the geopolymer system achieves the largest reduction. The study argues that material selection for sustainableconstruction should weigh strength development, durability, and carbonintensity jointly, and that supplementary cementitious materials offer apractical pathway to lower-impact concrete within existing constructionpractice. KEYWORDS: Green building materials, Embodied carbon, Supplementarycementitious materials, Fly ash, Ground granulated blast-furnace slag,Geopolymer, Sustainable concrete