Collaborative Research: New Natural Supplementary Cementitious Materials for Concrete

University Of Texas At Austin, Austin TX

Investigators

Abstract

Calcined impure clay and agricultural residue ash have the potential to dramatically reduce the amount of portland cement needed to make concrete, in turn reducing the adverse environmental impact and cost and improving long-term concrete durability. Current low-cost production methods for calcined clay and agricultural residue ash result in poor quality materials with low reactivity, limiting their use in construction. This research aims to develop thermochemical treatments to align the optimum burning conditions of clay and agricultural residue to produce a more reactive supplementary cementitious material. The specific research goals are as follows: 1) Quantify the change in optimum burning conditions and increased reactivity of calcined clays when flux additives are used, 2) Apply biomass pretreatments commonly used in biofuel production to agricultural residues to improve the quality of the ash for use in concrete, 3) Develop a methodology for combined calcined clay and agricultural residue ash production and use, and 4) Quantify the life cycle environmental benefit of the combined supplementary cementitious materials. The replacement of high volumes of portland cement with the proposed combined calcined clay/agricultural residue ash material could greatly reduce the greenhouse gas emissions associated with concrete construction and improve the quality of construction in developing countries since the proposed materials are low cost and widely available. This multi-institution collaboration will provide interdisciplinary training in agricultural engineering, civil engineering, materials science, and life-cycle analysis and improved classroom instruction on infrastructure materials and sustainability. A summer graduate student exchange will allow for improved collaboration and exposure to new equipment, research strategies, and laboratory methods. An outreach program will also be developed to increase the participation of female and historically underrepresented students in engineering and sustainable development.