Hybrid optimization of concrete mix design and sustainable formwork using recycled materials for low-cost rural housing

Project Abstract

Hybrid optimization of concrete mix design and sustainable formwork using recycled materials for low-cost rural housing presents a holistic approach to addressing housing shortages while reducing environmental impact and construction costs in rural communities. This study integrates material science, structural engineering, and sustainable construction practices to develop a cohesive framework for mix design optimization and formwork systems that leverage locally available recycled materials, such as crushed concrete, fly ash, slag, recycled plastic, and bamboo-reinforced components. The primary objective is to maximize structural performance, durability, and energy efficiency while minimizing embodied energy and total lifecycle costs. A multi-objective optimization model is formulated to balance fresh and hardened concrete properties (workability, compressive strength, split-tension, durability indices) with formwork sustainability metrics (reusability, weight, ease of de-molding, thermal performance, and waste generation). The optimization employs a hybrid algorithm combining genetic algorithms with particle swarm optimization and surrogate modeling to navigate the nonlinear relationships between material proportions, curing conditions, and manufacturing constraints. Experimental investigations include systematic mix design experiments across locally sourced cementitious systems and recycled aggregates, supported by accelerated curing and environmental exposure tests to evaluate strength development, sulfate resistance, drying shrinkage, and thermal conductivity. Parallel studies on formwork configurations examine modular reusable panels, low-weight scaffolding alternatives, and integrated insulative forms, assessing constructability, lifecycle waste, and seismic responsiveness for typical rural housing typologies. To ensure practicality, the research integrates life cycle assessment (LCA) and life cycle cost analysis (LCCA), capturing environmental footprints from material extraction to end-of-life, and the socioeconomic implications for rural builders and occupants. A numerical finite element model validates structural safety under service loads, wind, and seismic events, while a material durability model predicts long-term performance under local climate regimes. The expected outcomes include (i) a validated, region-specific optimized concrete mix design that achieves target strength with reduced cement content and enhanced durability using recycled constituents; (ii) a modular, reusable formwork system with superior thermal performance and reduced waste, compatible with low-skilled labor and rapid assembly; (iii) a decision-support framework and guidelines for rural contractors, policymakers, and non-governmental organizations to implement scalable, low-cost housing solutions; (iv) robust data on lifecycle environmental and economic benefits, demonstrating trade-offs between upfront costs and long-term savings. The research contributes to sustainable construction practice by demonstrating viable pathways for circular material use in concrete and formwork, while delivering tangible housing solutions that meet safety, durability, and affordability criteria in rural settings.

Project Overview

What This Project Is About

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A plain-language overview of how concrete mix choices and timber-based or recycled-fiber formwork can lower costs and reduce environmental impact in rural housing, while ensuring safety and durability. The project explores how combining optimized concrete recipes with sustainable, reusable formwork made from recycled materials can simplify construction, cut waste, and adapt to local materials and skills. It looks at how different mixes perform in typical rural conditions and how formwork design affects labor, time, and form accuracy. It also considers practical constraints like availability of materials, local weather, and budget limits.

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The Problem It Addresses

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Rural housing often suffers from high construction costs and low use of local, sustainable materials. In many places, waste from buildings is not reused, and formwork waste adds to costs. This project tackles the challenge of reducing material costs and environmental impact while maintaining strength and durability, by optimizing cement-based mixes and promoting reusable, recycled-material formwork.

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Objectives of the Project

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1. Identify cost-effective concrete mix designs that meet strength and durability needs for rural housing.
2. Evaluate sustainable formwork options made from recycled materials for ease of use and reuse.
3. Develop guidelines linking mix design choices with formwork type for best performance.
4. Assess environmental and economic benefits through a simple life-cycle view.
5. Provide a practical workflow for builders with limited resources.

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What You Will Do Step by Step

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1. Review basic literature on concrete mixes and formwork.
2. Collect local material data (types, costs, availability).
3. Test several concrete mixes for workability, strength, and durability in small samples.
4. Prototype simple formwork using recycled materials and test reuse capacity.
5. Compare costs and waste between traditional and proposed approaches.
6. Analyze results with simple calculations and plots.
7. Draft practical guidelines for local builders.
8. Prepare a final report and an easy-to-follow construction checklist.

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Expected Outcome

A clear, low-cost approach pairing optimized concrete mixes with sustainable, reusable formwork, plus simple guidelines and a decision toolkit for rural builders to improve affordability and environmental performance.