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 by means of two cases: a) concrete is being continuously mixed between the testing series; b) concrete is left at rest between the testing series, thus representing pauses during pumping. In Part 1 of the publication (CPI 5/15), the rheological principles of the concrete pumping process were presented and the experimental programme was described. In Part 2 of the publication (this paper), the experimental results are discussed and analysed.