This document discusses the use of mineral admixtures in concrete. It describes how fly ash, silica fume, and other mineral admixtures can replace a portion of cement in concrete, providing ecological and performance benefits. Fly ash improves workability and reduces heat generation during curing while increasing long-term strength. Silica fume improves strength, bonding, and permeability. The document outlines the materials used to test the effects of fly ash on concrete properties, including cement, aggregates, sand, fly ash, superplasticizer, and fiber.