Title:
Detection of Voids in Grouted Ducts Using the Impact-Echo Method
Author(s):
Nicholas J. Carino and Mary Sansalone
Publication:
Materials Journal
Volume:
89
Issue:
3
Appears on pages(s):
296-303
Keywords:
concretes; ducts; grout; impact; nondestructive tests; post-tensioning; prestressing steels; reinforcing steels; stresses; voids; walls; Materials Research
DOI:
10.14359/2596
Date:
5/1/1992
Abstract:
The impact-echo method was used to detect simulated voids in grouted post-tensioning tendon ducts cast in a 1-m (39.4-in.) thick concrete wall specimen. The study was part of a program sponsored by CANMET (Ottawa) to evaluate nondestructive test methods based on stress wave propagation. The locations of the voids in the ducts were not known until after their results had been reported to the principal investigator of the project. The impact-echo method successfully located most of the voids. The study provided impetus for additional experimental and analytical studies to better understand the interaction of stress waves with voids in cylindrical duct. It also highlighted the need to increase testing speed and develop a method to automate signal interpretation.