Avoidance of Blockages in Concrete Pumping Process

International Concrete Abstracts Portal

  


Title: Avoidance of Blockages in Concrete Pumping Process

Author(s): Denis Kaplan, Francois de Larrard, and Thierry Sedran

Publication: Materials Journal

Volume: 102

Issue: 3

Appears on pages(s): 183-191

Keywords: bleeding; blockage; process; pumped concrete; test

DOI: 10.14359/14446

Date: 5/1/2005

Abstract:
This paper describes a joint research project about concrete pumping. After a careful literature review was carried out, an experimental 148 m-closed-loop pumping circuit was built near Roissy, France. Over 68 concrete loads were pumped—a number of which were subject to blockage. These experiments led to significant advances in the understanding of the blockage process. Four types of blockages were pointed out. The most frequent happens at priming. It is due to coarse aggregate particles, which tend to leave the concrete front and to flow through the grout section, eventually forming a dense plug ahead of the flow. The tendency to segregate is correlated with bleeding, a phenomenon that is easier to reproduce in a small-scale test. Such a bleeding test was developed by modifying a conventional air meter, providing a simple and cheap site test. The initial bleeding rate was correlated with the likelihood of blockage in the pumping circuit. Finally, a broad analysis of the blockage formation could be proposed, giving clues to practitioners for a better control of the concrete pumping process.


ALSO AVAILABLE IN:

Electronic Materials Journal



  


ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

Edit Module Settings to define Page Content Reviewer