Title:
Prediction of Concrete Pumping: Part I—Development of New Tribometer for Analysis of Lubricating Layer
Author(s):
Seung Hee Kwon, Chan Kyu Park, Jae Hong Jeong, Seon Doo Jo, and Seung Hoon Lee
Publication:
Materials Journal
Volume:
110
Issue:
6
Appears on pages(s):
647-656
Keywords:
concrete pumping; lubricating layer; prediction; rheological properties; tribometer
DOI:
10.14359/51686332
Date:
11/1/2013
Abstract:
The character of the lubricating layer formed near the wall of a pipe during the flow of pumped concrete is a dominant factor facilitating concrete pumping. To predict flow rates of concrete transported by pumping, it is necessary to measure the rheological properties of the lubricating layer before pumping. In this paper, a new version of a test instrument called a tribometer is developed by considering the level of shear rate that induces the lubricating layer during real pumping. A test method is also suggested based on numerical simulation of the shear flow inside the tribometer and, finally, equations capable of transforming the values measured in the new tribometer into the rheological properties of the lubricating layer are derived. Work in this paper will be extended in a subsequent paper in which full-scale pumping tests will be performed, and predictions for concrete pumping based on the measurements of the new tribometer will be verified from comparisons with the test results.