Impacts of Coarse-Aggregate Gradation on the Workability of Slip-Formed Concrete

Abstract

Choosing an aggregate gradation is an important step in the design of concrete mixtures. This work presents a systematic laboratory study to find practical limits for the workability and finishability of these mixtures for slip-formed concrete applications. It investigates the upper and lower gradation limits for coarse aggregates, gradations that have no material on single and adjacent sieves, idealized aggregate gradations from previous publications, and insights into sieves responsible for cohesion and finishability of concrete mixtures for slip-formed applications. The work shows that a wide range of successful aggregate gradations can be used to produce concrete mixtures with satisfactory performance; however, certain gradation characteristics can lead to poor performance. These guidelines can be used to assist producers in making concrete mixtures with improved economy, durability, and sustainability.