4.3 Determination of mechanical properties of concrete at very early ages using advanced NDT techniques

Title: 4.3 Determination of mechanical properties of concrete at very early ages using advanced NDT techniques
Author(s): M. Krauß, K. Hariri, F.S. Rostásy
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
Print-ISBN: 2-912143-81-0
e-ISBN: 2912143705
Publisher: RILEM Publications SARL
Publication year: 2005
Pages: 143 - 162
Total Pages: 20
Nb references: 41
Language: English

Abstract: Early reports of Institute of Building Materials, Concrete Construction and Fire Protec-tion (iBMB) in the field of ultrasonic testing are presented by Eisenmann, Steinkamp and Odewald between 1951 and 1956. Eisenmann et al. investigated the influence of cracks in concrete on ultrasonic pulse velocity. In addition, they described the difference be-tween static and dynamic modulus of elasticity. This work was continued by Kordina, Waubke and Roy. Kordina et al. investigated the development of ultrasonic pulse veloc-ity as the velocity of the transverse and longitudinal waves as well as compressive strength increases. In 1974 Neisecke presented a new method to control the quality of mineral building materials. He measured the transverse wave velocity, longitudinal ve-locity and the intensity of the incoming signal. So, in principle, it was possible to meas-ure the development of dynamic Poisson's ratio and dynamic Young's modulus simulta-neously. The field of application of this method was, among other things, the observation of hardening process of concrete in the first 72 hours. Hillger continued this work. In 1983 Hillger presented an enhanced method by which the spectrum of the incoming signal could be analysed. This section gives a short survey of current field of application of the ultrasonic measuring technique on cement based materials at iBMB. The two above-mentioned publications form the basis of the further investigations presented this report.

In order to predict mechanical properties of concrete at very early age, non-destructive test methods are recommended. Combining such methods with standard destructive tests, reliable information regarding the mechanical properties can be acquired.

In this section a test method is presented to determine the so called end of dormant phase. At this time the mechanical properties, like Young's modulus and tensile strength, start to develop. This method is used to improve existing models of mechanical proper-ties models.

Online publication: 2006-09-22
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143705.006