Blocking analysis of fresh self-compacting concrete based on the DEM. (20th April 2018)

• Record Type: Journal Article
• Authors: Cui, Wei; Yan, Wei-shuo; Song, Hui-fang; Wu, Xin-li
• Is Part Of: Construction & building materials. Volume 168(2018)
• Page Start: 412
• Page End: 421
• Publication Date: 2018-04-20
• Subjects: Self-compacting concrete (SCC) -- Passing ability -- Random polyhedron aggregate -- Coarse-aggregate distribution -- Rebar distribution -- Discrete element method (DEM); Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.02.078
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: The irregularly shaped cluster particles are used to simulate the coarse aggregate. The effect of the coarse-aggregate distribution in causing the blocking are assessed. The effect of the rebar distribution in causing the blocking of SCC are compared. The randomness and variability of the blocking phenomenon are verified. Abstract: Self-compacting concrete (SCC) is a type of highly flowable, non-segregated concrete that can spread into place, filling formwork and encapsulate the reinforcement without mechanical consolidation. Nevertheless, SCC contains coarse aggregates that could get clogged within the reinforced zones during the casting process. When concrete flows through certain types of obstacles, such as steel bars, several phenomena occur that should be distinguished. In this study, the simulation of fresh SCC were described using irregularly shaped polyhedron particles instead of the traditionally used spherical particles because the former can more realistically approximate the actual state of the coarse aggregate. On this basis, in this paper, an analytical correlation between the blocking phenomenon and the coarse-aggregate distribution of SCC for the L-box test using the discrete element method (DEM) is proposed. The obtained results show that the aggregate size tends to affect the passing ability of SCC more than the coarse-aggregate content. Additionally, the free space between steel bars affects the passing ability of SCC more than the stirrup addition. Furthermore, multiple sets of simulation results indicate that blocking is fundamentally probabilistic, the probability of blocking from the SCC crossing a flow constriction increases with the number of aggregates crossing the obstacles, and this blocking process is demonstrated using the DEM.