On the real time assessment of pumping mixes under actual or quasi actual conditions

Author(s): O. Río, A. Rodriguez
Paper category: Symposium
Book title: 3rd International RILEM Symposium on Rheology of Cement Suspensions such as Fresh Concrete
Editor(s): O.H. Wallevik, S. Kubens, S. Oesterheld
ISBN: 978-2-35158-091-2
e-ISBN: 978-2-35158-092-9
Pages: 97 - 104
Total Pages: 8
Language: English

Abstract: 
Pumping is one of the most popular techniques worldwide to transport fresh concrete and reciprocating piston pumps the most widely used for placing large quantities of fresh concrete (mainly for structural uses) nowadays [1], [2], [3], [4], [5], [6].
However, for a certain number of applications neither the traditional engineering approach for characterising rheological problems [8], [9], [10], [11], [12], [13], [14] nor the Bingham approach [12], [13], [15], [16], [17], [18], [19] in the case of pumping performance may be considered more than just a first approximation for mix pumpability determination as it has been shown by some authors [13], [19]. They had shown also the need of exploring in deep how rheological parameters behaves under real on site pumping conditions [4], [6], [7] as suitability of the mix depends mainly on the tribology of the steel/concrete interface and on the pumping process parameters [7], [20].
The final aim of present authors research [20] is the development of a simple, affordable, and easy to apply pumping rheometer for allowing mix design [21]. On the other had, a second goal is to provide a real time method for controlling "on line" the concrete pumping process [12][20] for a given pumpable mix which will allow: 1) to regulate concrete flow according to actual mix properties, 2) an accurate determination of the pumped volume on real time [20] and 3) to implement an online quality control tool.
The first stage, which will present here, comprises the on site control sensing methodology use both comercial sensors but also specifically developed ones. The main advantage is that sensors directly installed on the pumping machine are relatively inexpensive non destructive measuring means that can be used not only for routine quality control on job site but also to allow the calibration of the new tool and methodology [21] proposed for mix characterisation. It will be completed by showing some real scale test results using the proposed sensing technology.

Online publication: 2009
Publication Type: full_text
Public price (Euros): 0.00