Crushed Glass as Fine Aggregate in Concrete

I was the Lead Researcher on this BSc project at the University of Lagos. I designed the experimental methodology, crushed and processed the glass samples, prepared and tested all concrete specimens across multiple replacement levels, ran the mechanical performance tests, analyzed the data, and wrote the final research document.

Sand is being consumed by the construction industry faster than it can be replenished, and millions of tons of waste glass end up in landfills every year. I wanted to find out whether two common types of waste glass, crushed beverage bottles (BB) and waste window panes (WP), could actually serve as partial replacements for natural fine aggregates in concrete.

Compare the mechanical performance of concrete made with crushed beverage bottles versus waste window panes as partial fine aggregate replacements

Evaluate compressive strength, flexural strength, split tensile strength, and durability across multiple replacement levels

Assess Alkali-Silica Reaction (ASR) risk and identify ways to control it

Provide data-backed recommendations for sustainable concrete production

I designed a systematic experimental program with 5 replacement levels: 0% (control), 10%, 20%, 30%, and 40%. Each level had both a beverage bottle version and a window pane version.

For each batch, I:

Crushed and sieved both glass types to controlled particle sizes below 1.18 mm to reduce ASR risk

Cast and cured test specimens following international testing standards

Ran compressive, flexural, and split tensile strength tests on every batch

Tested slump and durability to assess workability and long-term performance

Implemented ASR mitigation strategies including particle size control, supplementary cementitious materials, and low-alkali cement selection

Both glass types worked as fine aggregate replacements at moderate levels (10-30%). Some formulations actually showed strength improvements over the control at optimal replacement ratios.

But the two glass types aren't interchangeable. I found significant differences in chemical composition, surface attributes, and particle morphology between beverage bottles and window panes, and those differences produced measurable gaps in performance.

ASR remains the primary durability concern. I confirmed it can be effectively managed by keeping particle sizes below 1.18 mm (ideally 0.5 mm), using supplementary cementitious materials, and selecting low-alkali cement.

This research adds to the growing body of work on glass-concrete technology and provides a practical, tested framework for incorporating waste glass into concrete production, covering both the sustainability angle and the structural performance requirements.