Diseño de mezclas de concreto elaboradas con fibras metálicas, fibras de polipropileno y agregados procedentes de dos canteras; con uso potencial en el pavimento de la vía de enlace a la Subestación Villonaco

Abstract

Over the past three decades, It has been demonstrated the goodness of the concrete reinforced with fibers, however, when we deal with specific applications, all the efforts are concentrated on reducing costs. For this, we used fibers and aggregates of different nature to achieve a concrete of high performance and low cost. This research aims to study the effect of fibers addition and the type of aggregates in concrete to be used for paving secondary pathways. The prepared concrete shows a compression toughness of 35 MPa. Aggregates were used from two quarries located in the province of Loja: aggregate with rounded edge from the Boquerón River and shredded aggregates from the Malacatos River. The aggregates were characterized for their physical and mechanical properties. The methodology proposed by the ACI was used to design mixtures and achieving the components dosage to reach the required compression strength at the 28 days. Three different fiber concentrations were used to prepare concrete and so to be able to select the most suitable amounts of fibers to get improvements in the mechanical properties of the concrete. They were prepared cylindrical specimens and beams that later we evaluated to knowing their compressive and flexural strength. It was determined that the most convenient concentration of polypropylene fiber is 1,37 kg per cubic meter and 39,20 kg per cubic meter for metal fiber. With rounded edges aggregate and polypropylene fibers the relative increase in compressive and flexural strength was of 4 % and 6,9 %, respectively. While with rounded edges aggregate and metal fibers it was 9,8 % and 14,2 %, respectively. With shredded aggregates and polypropylene fibers the relative increase in compressive and flexural strength was 8 % and 6,1 %, respectively. While with shredded aggregates and metal fibers it was 13,5 % and 27,9 %, respectively.