Obtenção de concreto de ultra alto desempenho com adição de fibra de polietileno de alto módulo

Abstract

In the development of new technologies for construction, ultra-high performance concrete (UHPC) stands out. To be characterized as such, UHPC must meet regulatory parameters for spread, tensile strength, and compressive strength, which are 270 mm, 6 MPa and 120 MPa, respectively, at 28 days. Its composition commonly includes a high dosage of fine materials, the use of chemical additives and mineral admixtures, as well as the use of fibers, which ensures better tensile strength and toughness. In light of this, the study aimed to obtain UHPC using high-modulus polyethylene (HMPE) fibers. For this purpose, a reference UHPC without fibers was used, meeting UHPC characterizations established in previous studies, to which HMPE fibers were added. To obtain fiber-reinforced UHPC (UHPCFR), it was necessary to develop a mixing procedure using efficient mixers and methods to ensure homogeneity and fiber dispersion. Initially, for its introduction, HMPE was cut to a length of 15 mm and used in proportions of 0.10% and 0.15% relative to the volume of binders. Tests for spread in the fresh state and, in the hardened state, compressive strength, flexural tensile strength, and toughness were performed using cylindrical specimens (for compressive strength) and prismatic specimens (for flexural tensile strength and toughness). The results obtained showed that the addition of fibers significantly improved flexural tensile strength and toughness, highlighting the fiber’s potential when incorporated into UHPC.