Trade Journals for the Concrete Industry

This paper focuses on the influence of concrete composition on its rheological properties and pumpability. The pressure and flow rate results obtained for distinct concrete mixtures from the Sliding Pipe Rheometer (Sliper) are confronted with the rheological parameters obtained from a rotational viscometer and empirical tests. The characteristic differences in rheology and pumpability of ordinary concrete (OC) with rounded and crushed aggregates, self-compacting concrete (SCC) and strain-hardening cement-based composites (SHCC) are explored. In particular, the influence of pauses, i.e. blockages or temporary circuit breakdowns, on the pumpability of concrete are investigated. In Part 1 of the publication (this paper), the rheological principles of the concrete pumping process are presented. In addition, the experi- mental programme is described, with particular focus on the various testing techniques for concrete pumpability. In Part 2 of the publication (which will be published in CPI 6/15), the experimental results will be discussed.