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Srubar, III, Wil V.

Publications and source records attributed to Srubar, III, Wil V..

Geopolymer Cements: Resistance-Engineered Sewer Infrastructure for Longevity using Innovative, Energy-efficient, Synthesis Techniques (RESILIENT)

The primary objective of this project was to engineer an ultra-acid-resistant low-calcium alkali-activated cement paste for wastewater infrastructure applications to address the critical need for concrete materials with enhanced sulfuric acid resistance compared to ordinary Portland cement (OPC) concrete. In this project, the first milestone was to benchmark the sulfuric acid (SA) resistance of OPC and metakaolin-based geopolymer cement pastes. The second milestone was to model, select, and evaluate the efficacy of metal cation additions on the SA resistance of geopolymer cements. The third milestone was to create synthetic metakaolin that performed similarly to natural metakaolin. The fourth milestone was to design, build, and test the efficacy of four abiotic and biotic nano seeding agents. The fifth and final milestone was to quantify the breakeven material cost requirements and estimated environmental lifecycle costs of the most durable geopolymer cement formulations.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Sulfuric Acid Improves the Reactivity of Zeolites via Dealumination

The demand for supplementary cementitious materials (SCMs), like fly ash, slag, and silica fume, is projected to rise over the next few decades. However, global decarbonization efforts, such as decommissioning of coal-fired power plants, will limit the supply of SCMs. Therefore, alternative SCM sources are a critical need for the cement and concrete industry. However, the high crystallinity of zeolites limits their pozzolanic reactivity. The goal of this work was to improve the reactivity of two common zeolites, namely clinoptilolite and SSZ-13, by treating them with sulfuric acid. The treatment enhanced zeolite reactivity via dealumination and decreased particle sizes, which led to increased reactivity with calcium hydroxide, as indicated by a 42.0% increase in reaction heat measured by isothermal calorimetry. Here, we elucidate mechanistic understanding that smaller particle sizes induced by acid treatment accelerated peak heat evolution, while free aluminates from dealumination increased heat via direct reaction with aqueous Ca 2+ .

36 MATERIALS SCIENCE↗