LAUSR

AbstractCompacted blocks of coal fly ash and carbide lime (two industrial by-products) have a great potential as building products. This admixture can be used as an alternative to weight-bearing or nonstructural concrete masonry blocks due to the pozzolanic reactions occurring between silica and/or alumina in amorphous phases (found in the fly ash) and Ca++ (existent in carbide lime) in an alkaline environment. However, pozzolanic reactions are notoriously slow at ambient temperatures, requiring long curing periods to achieve the necessary strength for certain applications. Therefore, this study aims to verify the influence of coal fly ash ground towards the increase of unconfined compressive strength (qu) in fly ash–carbide lime blends. Results have shown that the ash grounds allowed an increase in qu for coal fly ash–carbide lime admixtures. It was found that coal fly ash ground for a short period of time (up to 2 h) increases the specific area of the fly ash grains by about 50%, while the strength at a...