Ultra-High Performance Concrete with Compressive Strength Exceeding 150 MPa (22 ksi): A Simpler Way

摘要

Although intensive research related to ultra high-performance concrete (UHPC) and its composition has been carried out over the past two decades, attaining compressive strengths of over 150 MPa (22 ksi) without special treatment, such as heat curing, pressure, and/or extensive vibration, has been nearly out of reach. This paper describes the development of a UHPC with a compressive strength exceeding 200 MPa (30 ksi), which was obtained using materials commercially available in the U.S. market and without the use of any heat treatment, pressure, or special mixer. The influence of different variables such as type of cement (C), silica fume (SF), sand, and high-range water reducer (HRWR) on compressive strength is evaluated. The test results show that the spread value, measured through a slump cone test on a flow table, is a good and quick indicator to optimize the mixture packing density and thus its compressive strength.