4.6 Impact-Echo

Title: 4.6 Impact-Echo
Author(s): C. U. Grosse, R. Beutel, S. Pessiki
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: 239 - 253
Total Pages: 15
Nb references: 23
Language: English

Abstract: Several years ago, the Impact-Echo (IE) method, that considerably improved the detection of voids and honeycombing, was introduced by Carino and Sansalone (1992). The strength of this method is its ability to detect voids in structures and to measure the thickness of concrete parts with good accuracy. However, this technology is still not widely accepted due to the poor handling and limited functionality of commercially available equipment based on this approach. Moreover it was shown [Colla et al. (1999)] that single-point measurements are somehow more difficult to be interpreted compared to measurements using a scanning technique. The so-called scanning IE technique was developed from measurements that were carried out by Weiler (1995) on sandstone and later on by Grosse and Weiler (1997) as well as Kretschmar et al. (1997) on concrete. A more sophisticated approach using a static scanning frame was described by Colla et al. (1999) and Lausch et al. (2002). It is obvious that the potential of this technique is currently not being used to its full extent regarding handling as well as analyzing techniques, therefore the economic value of this method is underestimated.

A testing device based on ultrasonic techniques was developed at the Institute of Construction Materials, University of Stuttgart, to analyze the setting and hardening of cement-based materials. This method is partly described in section 4.2 and in numerous publications [Grosse & Reinhardt (1994); Grosse et al. (1999); Reinhardt et al. (1999a)] and in the meanwhile patented [Reinhardt et al. (1999b)].

A disadvantage of the through-transmission technique is that the access is required to both sides of the material to enable a wave travelling through the material. To avoid the disadvantage of the through-transmission techniques the impact-echo method was tested. It combines the option to have a one-side access with the ability to evaluate the full body of a specimen or a construction part during its setting and hardening. This procedure was first suggested by Pessiki et al. (1988)

Online publication: 2006-09-22
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143705.009