Work

Calcium-Rich Fly Ash as a Sustainable Supplementary Cementitious Material for Enhanced Sulfate Resistance and Durability of Cementitious Composites: Experimental and Microstructural Perspectives

Year: 2025

Type: article

Abstract: This study explores the potential of calcium-rich fly ash from the Ptolemais region in Greece as a partial cement replacement for improving sulfate resistance in cementitious composites. An integrated experimental program, combining mechanical testing, electrochemical corrosion monitoring and microstructural characterization, was designed to capture the progression of material properties over time and their impact on performance. The experimental results proved that, at early ages, incorporation of fly ash led to reductions in compressive, tensile and bond strengths, attributed to delayed pozzolanic reactivity. However, over prolonged curing, secondary reactions consumed portlandite and generated additional calcium silicate hydrate, refining the pore network and reducing permeability. These microstructural improvements were associated with enhanced mechanical performance, improved durability indices and markedly lower reinforcement corrosion rates. Bond tests further revealed a shift from brittle to a more ductile response, offering advantages for repair applications. These findings establish calcium-rich Ptolemais fly ash as a as a sustainable and promising supplementary cementitious material that substantially enhances the long-term durability and sulfate resistance of cementitious systems.

Source: Materials

DOI: 10.3390/ma18184238

Authors: Nikolaos Chousidis, George Batis

Institution: National Technical University of Athens

Language: English

Topic: Concrete and Cement Materials Research

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $3,137