Journal Published Online: 05 October 2015
Volume 44, Issue 1

Robust Test of the Flatbed Scanner for Air-Void Characterization in Hardened Concrete

CODEN: JTEVAB

Abstract

In the province of Ontario, Canada, the Ministry of Transportation administers a quality assurance testing program for all new concrete construction where air content and spacing factor are measured. Testing is performed by qualified operators in accordance with ASTM C457/C457M-12. In this study, 324 routine samples that had been tested by qualified operators were obtained and analyzed for air-void parameters by an alternative automated flatbed scanner method. A strong correlation was found between the manual and automated methods. This research explored the premise that summary statistics from a small set of training samples could be used to define a set of global threshold levels to measure air-void parameters from a much larger population. Two different methods for setting the global thresholds were tested: one based on arithmetic means, and another based on modal location parameters derived from type I extreme value distributions. The frequency of false-negative errors (failure to detect a defect) was used as a criterion to assess the different threshold methods. Automated test results derived using global thresholds based on arithmetic means minimized the occurrence of false-negative events.

Author Information

Peterson, Karl
Univ. of Toronto, Dept. of Civil Engineering, Toronto, ON, CN
Anzalone, Gerald
Michigan Tech. Univ., Dept. of Materials Science and Eng., Houghton, MI, US
Nezami, Sona
Univ. of Toronto, Dept. of Civil Engineering, Toronto, ON, CN Read Jones Christoffersen, Toronto, ON, CN
Oh, Claire Yea
Univ. of Toronto, Dept. of Civil Engineering, Toronto, ON, CN
Lu, Haizhu
Univ. of Toronto, Dept. of Civil Engineering, Toronto, ON, CN
Pages: 16
Price: $25.00
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Details
Stock #: JTE20140432
ISSN: 0090-3973
DOI: 10.1520/JTE20140432