Potential use of binary fly ash-ground granulated blast furnace slag mixtures as precursors in low-carbon sulfate-activated composites

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:The paper provides a systematic experimental dataset on FA/GGBFS ratio optimization in sulfate-activated systems, useful for further materials science research.

🏢実務担当者:Construction firms can use the 15-20% FA replacement ranges to formulate low-carbon concrete with balanced performance and cost.

Abstract This study investigates the feasibility of using binary fly ash (FA) and ground granulated blast-furnace slag (GGBFS) mixtures as precursors for low-carbon sulfate-activated composites activated with sodium sulfate. The FA/GGBFS ratio was systematically varied to clarify its influence on fresh properties, strength development, durability-related indicators, microstructural characteristics, and sustainability performance. The results show that increasing FA content improved flowability but significantly prolonged both initial and final setting times. In terms of physical performance, FA incorporation up to 15% promoted matrix refinement, as reflected by reduced porosity and water absorption, while higher replacement levels led to less consistent improvement. Mechanical test results indicated that the mixture containing 15% FA (F15S85) provided the most balanced strength development within the investigated range, achieving the highest flexural strength (3.94 MPa) and compressive strength (55.14 MPa) at 56 d. Drying shrinkage decreased progressively with increasing FA content, with the 20% FA mixture showing the lowest shrinkage, whereas F15S85 offered a more favorable balance between strength and dimensional stability. Ultrasonic pulse velocity and rapid chloride ion penetration test results further confirmed that moderate FA incorporation improved matrix compactness and resistance to chloride ingress. Scanning electron microscopy observations showed a denser and more homogeneous matrix in mixtures containing 10%–15% FA, while x-ray diffraction patterns qualitatively indicated changes in crystalline phase characteristics with increasing FA replacement. From a sustainability perspective, increasing FA content reduced both material cost and CO 2 -equivalent emissions, with F20S80 showing the greatest economic and environmental benefit. Overall, the results indicate that partial replacement of GGBFS by FA can improve the balance between performance and sustainability in sulfate-activated systems. Within the investigated range, F15S85 showed the most favorable mechanical performance and matrix compactness, whereas F20S80 provided greater benefits in shrinkage reduction, material cost, and CO 2 -eq efficiency.

• openalex https://doi.org/10.1088/2053-1591/ae8363first seen 2026-07-13 05:53:05