ERI: Engineering Properties of Eco-Friendly Ultra-High-Performance Concrete using Mine Waste and Green Binder for Sustainable Infrastructure

Concrete is responsible for over 7 percent of the world’s CO2 emissions. Because of these devastating environmental impacts, it is critical to develop alternative, eco-friendly solutions for concrete. This Engineering Research Initiation (ERI) award supports the development of a novel Ultra-High-Performance Concrete (UHPC) that addresses environmental sustainability and volume instability issues in traditional UHPC.

The innovative UHPC involves replacing carcinogenic quartz materials with waste mine tailings and incorporating a green ternary binder system composed of low-carbon super-sulfated cement, silica fume, and magnesium oxides. This research aims to reduce the carbon footprint and production costs of UHPC while promoting waste material utilization, contributing to a circular economy and national prosperity.

Enhanced volume stability and mechanical performance will improve infrastructure resilience, particularly in regions prone to natural disasters and climate change. Furthermore, this research provides valuable cross-disciplinary training in concrete sustainability and material synthesis and characterization for both graduate and undergraduate students from diverse backgrounds at Texas A&M University-Corpus Christi, a Minority and Hispanic-Serving Institution.

Researchers will also engage with outreach programs to recruit talented K-12 students and women to participate in STEM fields.

The goal of this research is to investigate how the integration of different particle size distributions of waste granular mine tailings and a ternary binder system alters the synthesis, physicochemical, and mechanical properties of UHPC across multiple scales. To accomplish this goal, the researchers will conduct three main tasks: (i) Optimize the volume fractions and particle distribution of magnesium iron silicate waste mine tailings using a packing model to minimize physical interlocking and discontinuities, thus enhancing mechanical properties; (ii) Unveil the hydration mechanisms of the combined binder system and assess how silica fume acts as a catalyst for the formation of Calcium-Silicate-Hydrate (C-S-H) and Calcium-Aluminum-Silicate-Hydrate (C-(A)-S-H), and how magnesium oxide contributes to the creation of Magnesium Silicate Hydrate (M-S-H), thereby densifying the microstructure and enhancing cohesion, friction, and fracture properties; and (iii) develop statistical models that understand the trade-offs between properties such as mechanical performance and volume stability, and mix design parameters and their interactions, enabling new predictive capabilities.

This project will lead to the development of a sustainable and resilient UHPC for infrastructure applications.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.