Optimization of Geopolymer Concrete Mixtures for Sustainable High-Strength Construction in Seismic Zones

Project Abstract

This study presents a comprehensive investigation into the optimization of geopolymer concrete (GPC) mixtures to achieve sustainable, high-strength performance suitable for construction in seismic zones. The research addresses the urgent need to reduce reliance on Portland cement due to its high embodied energy and carbon footprint, while maintaining or surpassing the structural efficiency required for earthquake-resilient design. A multi-objective optimization framework is employed, integrating material science, structural performance, and sustainability metrics to identify mix designs that maximize compressive strength, flexural strength, and durability while minimizing embodied energy and CO2 emissions. The experimental program is anchored by a systematic screen of aluminosilicate precursors (fly ash, metakaolin, and slag), alkaline activators (sodium silicate and sodium hydroxide solutions with varying moduli and concentrations), and aggregate gradations to produce GPCs with target strength classes up to high-performance levels. Key variables such as the liquid/solid ratio, activator modulus, curing regime (ambient versus elevated humidity and temperature), cure time, and supplementary cementitious materials are explored through a design of experiments (DOE) approach to elucidate interactions and nonlinear effects on early-age and long-term strength, microstructure development, and exposure resistance under simulated seismic loading. Advanced characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermo-gravimetric analysis (TGA), are used to correlate microstructural evolution with macroscale properties and to identify the dominant geopolymerization pathways that govern fracture energy and residual strength after dynamic loading. The seismic performance assessment comprises nonlinear static push-over analyses and nonlinear time history analyses on validated finite element models of reinforced concrete frames and GPC-based retrofits, incorporating variable stiffness, damping, and deterioration effects. Life cycle assessment (LCA) and environmental product declarations (EPD) are conducted to quantify cradle-to-gate and cradle-to-site impacts, enabling a comparative evaluation against conventional reinforced concrete benchmarks. The optimization results reveal a family of adaptable mix designs that deliver high early strength and accelerated curing compatible with rapid construction schedules, while achieving superior durability against chemical attack, sulfate exposure, and thermal cycling typical of seismic environments. Sensitivity analyses identify key trade-offs between early-age strength, long-term performance, and sustainability indicators, informing practical guidelines for field mix proportioning, quality control, and standardization. The study culminates in a proposed design framework for seismic-resistant GPC structures, including recommended dosage ranges, curing practices, and performance targets aligned with contemporary seismic codes and green construction initiatives. The findings demonstrate that geopolymer concrete can deliver comparable or enhanced mechanical performance and ductility relative to conventional mixes, with substantially reduced carbon footprint, thereby supporting safer, more sustainable construction in earthquake-prone regions without compromising buildability or lifecycle reliability.

Project Overview

What This Project Is About

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A simple, practical study of using geopolymer concrete in place of traditional cement-based mixes to build strong, durable structures that perform well in earthquakes. The project explores how mix choices, curing methods, and materials influence strength, durability, and eco-friendliness.

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The Problem It Addresses

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Cement production is energy-intensive and contributes to carbon emissions. Conventional concrete can be heavy and crack-prone in seismic events. This project looks at a greener alternative that maintains safety and performance in earthquakes while reducing environmental impact.

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Objectives of the Project

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1. Compare geopolymer mixes to ordinary concrete in terms of strength and early strength gain.
2. Evaluate durability indicators relevant to seismic zones (crack resistance, chloride penetration, fire resistance).
3. Identify mix designs that optimize both performance and sustainability.
4. Develop practical guidelines for small-scale laboratory testing and potential field use.

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What You Will Do Step by Step

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1. Learn basic concepts of geopolymer chemistry and concrete testing. 2. Design simple geopolymer mixes using available materials. 3. Prepare and cure samples under controlled conditions. 4. Test mechanical properties (strength, elasticity) and durability. 5. Compare results with standard concrete data. 6. Analyze data to find the best-performing mix. 7. Assess environmental impact and cost considerations. 8. Compile findings into practical recommendations.

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Expected Outcome

Clear evidence on whether geopolymer concrete can meet or exceed the performance of traditional concrete in seismic scenarios, plus a set of ready-to-use mix guidelines and sustainability benefits.