Title: 4.1 Basics
Author(s): H. W. Reinhardt, C. U. Grosse
Paper category : book
Book title: Advanced Testing of Cement-Based Materials during Setting and Hardening - Final Report of RILEM TC 185-ATC
Editor(s): H.W. Reinhardt and C.U. Grosse
Publisher: RILEM Publications SARL
Publication year: 2005
Pages: 83 - 96
Total Pages: 14
Nb references: 9
Abstract: The most important physical quantities with respect to the wave propagation in cementitious materials are the propagation velocities and the elastic modules as well as the de-rived quantities. They are the key for the characterisation of the elastic properties of a material by mechanical waves especially during stiffening and hardening. The aim is the description of a testing specimen with as less as possible handable measuring quantities. As the general description of the elastic behaviour of a solid show the derivation of the quantities is tied on some prerequisites. The knowledge of these boundary conditions are especially important because they are responsible for the fact whether the elastic quantities can be determined with sufficient accuracy or whether the selected measuring method is suitable for the task.
When a material is investigated with sound or ultrasound waves the determination of the body and surface wave velocities have a special impact because these quantities can be measured easily. Wave velocities are connected to other elastic quantities in an elementary way. It is good to know how, for instance, the elastic modules (compression modulus, shear modulus, Poisson ratio, Lamé´s parameters, etc.) depend on the wave velocities. Under certain physical circumstances (no layers, homogeneity) a relation between the compression wave velocity, the Rayleigh wave velocity and the elastic parameters can be established when the density is known. In the literature, for instance [Landau & Lifschitz (1986)], these relations are described, however in a form that they cannot be used easily for the practice of ultrasound testing. In the following, the derivation of the relevant equations and their relations are clearly given.
Online publication: 2006-09-22
Publication type : full_text
Public price (Euros): 0.00