Estimation of the Pumping Pressure from Concrete Composition Based on the Identified Tribological Parameters

Abstract

A new method is proposed to estimate pumping pressure based on concrete composition without experimental measurements. Previous studies show that the pumping pressure depends on the interface friction between concrete and the wall of the pumping pipes. This friction is determined by the thickness and the rheology of the boundary layer formed at the interface. The latter is mainly formed by water, cement, and fine sand particles which come from concrete. Hence, interface parameters, which are the viscous constant and the interface yield stress, are directly related to concrete composition. In this work, at the first time the interface yield stress model is suggested and validated thanks to an experimental database also carried out in this study with a precision of around 13%. Then, the pressure estimation method is proposed using the two models to calculate the interface parameters. The validation of the method is carried out basing on the comparison with real measurements on the building site. This method enables the calculation of the pumping pressure with a precision of around 15%.

A Review on the Pumping Behavior of Modern Concrete

“…The concrete pumpability can be enhanced by increasing the cement paste volume, water-cement ratio and superplasticizer dosage (Ling and Kwan 2015;Ngo et al 2012). Although the increase of the water-cement ratio can improve pumpability, it is easy to induce segregation, bleeding and pipe blockage in the pumping process (Mai et al 2014;Felekoglu et al 2007). The pumpability is highly associated with both the workability and stability of the fresh concrete.…”

“…The yield stress becomes increasingly important at lower viscosity. Different values of rheological parameters may be acquired for the same mixtures when testing by different instruments (Mai et al 2014). Kaplan et al (2005b) reported that the viscous constant (rather than the yield stress) of the lubrication layer was the major factor for pumpability.…”

Experimental Investigation of the Pumping of a Model-Concrete through Pipes

“…The formation of the lubricating layer has been frequently investigated in recent years, for example by ultrasonic velocimetry [17], pressure loss measurements [15,18,19], and Particle Image Velocimetry (PIV) on the surface of the flowing material [20]. In addition, the influence on the pressure loss has been investigated by numerical simulation [21].…”

Safety state identification of concrete pumping pipeline based on multi-channel audio signals

“…Chen et al [7] obtained and verified the empirical relationship between the surface strain of the pipeline and the pressure on the inner wall of the pipeline, and they also monitored the flowing concrete pressure on the inner wall of the pipeline by measuring the strain on the outer surface of the pipeline. With the help of the database which recording the interfacial yielding stress inside the pipeline, viscosity constants and concrete grading, Mai et al [8] established a computational model relating the concrete grading to yielding stress and pressure inside https://doi.org/10.1051/e3sconf/202019801001 E3S Web of Conferences , 01001 (2020) ISCEG 2020 the pipeline. This model was able to evaluate the pressure inside the pipeline with relative error around 15%.…”