Denis Bruneau

Experimental investigation of the homogeneity of the blended binder of a high rate recycled asphalt

Nowadays, with the increasing material costs and the environmental needs to reduce energy consumption and greenhouse gases emission, the technique of asphalt recycling becomes more and more used in the road industry. To ensure the performance of recycled asphalt, a quality control of the bituminous mixture is required. In this context, this work was carried out within the framework of a partnership between the IRC/ESTP and the company Eurovia. In this paper, we present an experimental approach to characterise the level of blending of the binder from reclaimed asphalt pavement (RAP) in hot recycled bituminous mixture. First, a series of laboratory tests are performed on asphaltic concrete including 70% of RAP to extract the bituminous binder mixture using an appropriate solvent. This leads to define an appropriate progressive extraction procedure that allows a regularly stripping of the recycled concrete (three solutions containing about 30% of the bituminous binder). Then, both conventional tests and infrared spectroscopy analysis are performed in order to quantify the evolution of the RAP and virgin binders mass proportions during the stripping process. The experimental results show a “bad” remobilisation of the virgin bitumen in the blended binder of the hot recycled bituminous mixture. This finding correlates with the hypothesis of the “heterogeneous asphalt” considered during the manufacture process.

An Experimental Study of Wheat Drying in Thin Layer and Mathematical Simulation of a Fixed-Bed Convective Dryer

Drying of wheat (Algerian cultivar: Hadba03) in thin layers was studied and mass flux phenomenon was used to characterize the thin-layer drying process. Thin-layer drying of wheat was determined for drying air temperature range of 40–60°C, relative humidity of drying air from 10 to 30%, air velocity of 0.7 m/s, and initial grain moisture from 26 to 31% (dry basis). Equilibrium moisture content of wheat was determined using desorption isotherms obtained from the thin-layer drying data. An equilibrium model for a stationary deep bed with drying air moving vertically upward was developed using mass and energy balance between grain and drying air in the bed and drying air characteristics obtained from thin-layer drying experiments. The developed model was validated by drying wheat in a laboratory dryer using different drying air temperatures and initial moisture contents.

Toward a New Method of Porosimetry: Principles and Experiments

Current experimental methods used to determine pore size distributions (PSD) of porous media present several drawbacks such as toxicity of the employed fluids (e.g., mercury porosimetry). The theoretical basis of a new method to obtain the PSD by injecting yield stress fluids through porous media and measuring the flow rate

DRYING OF A PAPER COATING : EXPERIMENTAL STUDY AND MODELLING

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On the Influence of Permeability and Young's Modulus on the Dehydration of a Strongly Shrinkable Two-Phase Porous Medium: A Model Sensibility Analysis and the Development of a Contact Mechanics Measurement Setup

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Mesure de cartographies de teneur en eau par imagerie térahertz

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