| Ultra high strength concrete (UHSC) mixture proportions were developed using local materials so that UHSC may be made more affordable to a wider variety of applications. Specifically, local sand with a top size of 600microm (0.0236 in.), and locally available Type I/II cement and silica fume were used in this research. Each of these material selections is seen as an improvement in sustainability for UHSC. Two mixtures (one with and one without fibers) were recommended as the UHSC mixtures. The greatest compressive strengths obtained in this study were 170.3 MPa (24,700 psi) for UHSC with steel fibers and 159.9 MPa (23,190 psi) for UHSC without fibers. The greatest flexural strengths were 17.5 MPa (2650 psi) and 10.9 MPa (1580 psi) for UHSC with and without fibers, respectively. Producing this innovative material with local materials reduces the cost of the material, improves sustainability, and produces mechanical performance similar to prepackaged, commercially available products.;After developing the UHSC mixtures, early-age and long term shrinkage of plain and fiber reinforced UHSC were investigated. Shrinkage of UHSC was measured under two conditions: (1) air drying and (2) heat curing. Due to the restraining influence of steel fibers, early-age and long term shrinkage values for fiber reinforced UHSC were lower than those of plain UHSC. Early-age shrinkage of plain UHSC (2726micro) was 54.9% greater than the early-age shrinkage of fiber reinforced UHSC (1758micro). When specimens were air dried, the total shrinkage of plain UHSC specimens was greater than the total shrinkage of fiber reinforced specimens by 43.9%. When the specimens were heat cured, total shrinkage of plain and fiber reinforced UHSC specimens that occurred during nine days was measured to be 4251micro and 2822micro, respectively, while the total shrinkage of fiber reinforced UHSC specimens that occurred during 30 days of heat curing was 3006micro. |
