Title: Design and performance of precast, prestressed concrete beams made with fly-ash-based alkali-activated concrete
Date Published: July - August 2025
Volume: 70
Issue: 4
Page Numbers: 35 - 51
Authors: Grant P. Magnuson, Mary U. Christiansen, and Benjamin Z. Dymond
https://doi.org/10.15554/pcij70.4-02

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Abstract

This paper presents the development and implementation of a fly-ash-based alkali-activated concrete mixture for use in precast, prestressed concrete beams. Alkali-activated concrete, which contains no portland cement and often incorporates recycled materials, offers an environmentally friendly alternative to conventional concrete. The study evaluated over 40 mortar mixtures to identify a design suitable for precasting plant production. Full-scale beams and mechanical property specimens were fabricated and tested, alongside comparable portland cement concrete specimens. Results showed that the structural performance of alkali-activated concrete beams varied from code-based predictions, highlighting the need for further refinement in design and fabrication methods. The research provides practical insights into adapting alkali-activated concrete for precast applications, including lessons learned on production constraints and material behavior.