Effect of Total Replacement of Quarry Aggregate by River Aggregate on the Strength of Concrete

Currently, the collection and crushing process of fine and coarse aggregate has become costly and transportation time has increased due to the complexity of certain areas in the Peruvian highlands. As a consequence, river aggregate is extracted as a total substitution of fine and coarse aggregate for the preparation of structural concrete, but it is not known for sure if it is totally viable to use this aggregate for the benefit of construction interests. Therefore, the objective of this study is to evaluate the total substitution of fine and coarse aggregate by river aggregate obtained from the city of Cajamarca, Peru, on the mechanical properties of concrete. Concrete specimens were manufactured with fine and coarse aggregate and others with river aggregate from the Huaquillo and Portachuelo quarries, respectively. It is considered the designs of 175 kg/cm2 and 210 kg/cm2, in addition to tests such as slump, unit weight, compressive strength, flexural strength and an analysis of variance (ANOVA) in Tukey's block. An experimental campaign was carried out with cementitious pastes to evaluate the effect on physical and mechanical properties due to the use of river aggregate; the samples containing fine aggregate and coarse aggregate revealed good results in terms of mechanical properties. However, concrete made with river aggregate meets the minimum required theoretical design strength and is suitable to be used as a total substitute, which is a new and important scientific issue to highlight.