Determinación del módulo de elasticidad y la resistencia a compresión del hormigón en función de la variabilidad y caracterización de los agregados

Abstract

The modulus of elasticity of concrete is associated with structural deformations that must be kept within the established limits, to avoid excessive deformations that cause cracks and other failures in concrete structures. To estimate this parameter, normative empirical approaches have emerged, based on the compressive strength of concrete, in Ecuador the Norma Ecuatoriana de la Construcción (NEC-SE-DS) has adopted the empirical equation proposed by the ACI code, which has presented significant variability in different parts of the world, the main factor being the aggregates since they correspond to 70% of the volume of the concrete. The objective of this research is to determine the modulus of elasticity and the compressive strength of concrete according to the variability and characterization of the aggregates. The method is based on making 12 types of concretes based on the aggregate most used by Cuenca concrete mixers, water-cement ratio and fine aggregate-coarse aggregate ratio. The data are processed through a variance analysis to determine if the factors exert effects on the dependent variables. The equation of the ACI 318 adopted by the NEC-SE-DS was validated for the concretes designed with aggregates used by concrete mixers of the city of Cuenca, since they are within the range established by the standard. It was established that for both the ASTM C-469 method and ultrasound, the water-cement ratio is the factor that best represents the variability of the values of modulus of elasticity and resistance to simple compression. The fine aggregate-coarse aggregate ratio, although it had a significant influence on the modulus of elasticity, represented a lower influence than the water-cement ratio in this parameter. On the other hand, the compressive strength was not affected by the fine aggregate-coarse aggregate ratio.