Effects of Aggregate Concepts on the Workability of Slip-Formed Concrete: Fid-Bau Portal

Effects of Aggregate Concepts on the Workability of Slip-Formed Concrete

Cook, Marllon Daniel / Tyler Ley, M. / Ghaeezadah, Ashkan

Only a small amount of published literature has presented any agreement on how aggregate properties affect the workability of concrete, and some of these historic aggregate design methods may give conflicting recommendations. This research aims to provide insight by comparing several historic aggregate concepts to the workability performance of low flow concrete for slip-formed applications. The workability performance of each mixture was measured using the slump test and the box test. By leaving the paste volume constant and systematically changing aggregate concepts such as gradations and proportioning techniques, it allowed for a quantitative comparison between these different aggregate concepts and techniques. The results show the individual percent retained (IPR) chart was the most useful to predict influences of aggregate gradation. Other aggregate gradation and proportioning concepts such as the coarseness-factor chart, the Power 45 chart, specific surface area, and some popular packing methods were not able to accurately predict workability performance for slip-formed applications. The shape and texture of aggregate was also shown to be important for workability of these mixtures.