EFFECT OF CURING TECHNIQUE ON DEVELOPMENT OF HIGH STRENGTH CONCRETE FROM 10MM (3/8) LOCALLY OCCURRING GRAVEL AGGREGATE MATERIALS

In addition to affordability, modern concrete is expected to satisfy other technical and functional requirements such as high strength, corrosion resistance and enhance thermal insulation and energy efficiency. Concrete remains the most widely used construction material, accounting for about fifty percent of the total built facilities. Concrete basically comprises cement, aggregates, water and admixtures. Thus normal concrete represents a three-phase composite material containing the mortar phase, mortal/aggregates interface and the coarse aggregate phase. The coarse aggregates in normal concrete are mainly from rock fragments characterized by high strength. The strength of the concrete at the interfacial zone essentially depends on the integrity of the cement paste and the nature of the coarse aggregate. The presence of the aggregates size greater than 10 mm predominantly affects the homogeneity and strength development of the concrete. Thus, normal concrete in its basic state is weak on account of the presence of a weak interfacial zone; its failure is manifested in the initiation, development and growth of cracks principally around the cement paste or at the aggregate/cement paste interfacial zone.