Study of the concrete overlay (whitetopping) in paving using computed tomographic system

The aim of this paper is to demonstrate the feasibility of using computed tomographic system to study the concrete paving. Tomography refers to the cross-sectional imaging of an object from transmission data collected by illuminating the object from many different directions. The mathematical algorithms for tomography reconstruction are based on projection data, which represent the attenuation of photons through an object. Projection data are a result of interaction between the radiation used for imaging and the substance in which the object is composed. The incident beam undergoes attenuation as it travels through an object. This attenuation is due to the photons either being absorbed by the atoms of the material, or being scattered away from their original directions of travel. The aim of computed tomography (CT) is to reconstruct a cross-sectional image of the attenuation coefficient. This work applies the CT technique to the study of concrete mixture. The specimens were constructed with and without fiber. We also have studied the distribution of percentage voids in both specimens and the distribution of fiber in only one specimen. It can be noticed a different distribution of particle sizes for both specimens was studied. (c) 2007 Elsevier B.V. All rights reserved.