Title: A Collaborative Study to Determine the Critical Chloride Threshold Test, OCcrit, Variability due to Material Sources

Author(s): Ceki Halmen, PhD, PE

Publication: CRC

Volume:

Issue:

Appears on pages(s): 42

Keywords:

DOI:

Date: 1/1/2024

Abstract:
The Clcrit data published in the literature exhibits significant scater and varies between ~0.1 and 3.1% by weight of cement. An important factor for this variability was believed to be due to the lack of a standard test method. To address this issue, the ACI 222 committee established a task group, TG1, to develop a standard Clcrit laboratory test method. TG1 conducted a CRC funded research study (Phase I study) and evaluated two different test methods developed based on a general framework established by the task group. This study showed that the OCcrit test method developed at the Oregon State University was providing consistent results with good inter- and intra-laboratory variability and the task group recommended further evaluation of this test method which initiated the Phase II study described in this report. The objective of this study was to measure the variability of OCcrit data due to different sources of materials that meet the requirements of the same ASTM specifications. Cement mee􀆟ng the specifications of ASTM C150 Type I/II cement was procured from three different suppliers and steel meeting the specifications of ASTM A615 Grade 60 was procured from three different suppliers. These materials were tested using the OCcrit method in five different laboratories consisting of academic and commercial labs to report the observed Clcrit values.