Mechanical Properties of Ultra-High-Performance Concrete with Steel and PVA Fibers.

Ultra-high-performance concrete (UHPC) has gained worldwide popularity due to its high mechanical performance. This research studied the influence of adding a mixture of two fibers (steel and PVA) on the compressive strength, modulus of elasticity, and flexural tensile strength of UHPC. The mixtures were prepared by adding steel fibers and PVA fibers using a standard procedure defined in the research, which is the time to mix the dry materials and the time to mix the admixture and water.

Study of Ultra-High Performance Concrete Mechanical Behavior under High Temperatures.

The main concern with concrete at high temperatures is loss of strength and explosive spalling, which are more pronounced in high-strength concretes, such as Ultra-High Performance Concrete (UHPC). The use of polymeric fibers in the mixture helps control chipping, increasing porosity and reducing internal water vapor pressure, but their addition can impact its mechanical properties and workability. This study evaluated the physical and mechanical properties of UHPC with metallic and PVA fibers under high temperatures using a 2 central composite factorial design.