Reliability of chloride testing results in cementitious systems containing admixed chlorides

ABSTRACT

Chloride concentrations are often evaluated for concrete mixtures used in new construction for quantity control purposes. This paper reports on the reliability of results from ASTM C1152 (acid-soluble) and ASTM C1218 (water-soluble) tests commonly adopted for measuring chlorides in concrete. The effects of cementitious material type, water-binder ratio, admixed chloride level, and degree of carbonation on chloride concentrations of cementitious systems are evaluated. Results show that the release of bound chlorides due to carbonation could be represented by an increase in ASTM C1218 test value. Chloride concentrations measured using ASTM C1152 testing could be significantly lower than the actual chloride concentration for carbonated systems. This underestimation, as a percent of total chloride concentration, could be as high as 40% depending on the cementitious material type and chloride admixed level. Preliminary results indicate that ASTM C1218 could be more reliable when compared to ASTM C1152 for systems with admixed chlorides.

KEYWORDS:

• Accelerated-carbonation
• admixed-chlorides
• acid-soluble
• water-soluble
• bound-chlorides
• speciality cements

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Ahmed A. Ahmed

Ahmed A. Ahmed is a faculty member of infrastructure materials in the Department of Civil Engineering at Mustansiriyah University, Baghdad, Iraq. He received his PhD from the School of Civil and Construction Engineering at Oregon State University, Corvallis, OR. He is an associate member of ACI committee 222, 370, and 546. His research interests include transport properties, carbonation, chloride profiling and corrosion evaluation, and durability of specialty cementitious systems.

ACI member Naga Pavan Vaddey is an Associate II at CTLGroup, Skokie, IL. He received his PhD from Oregon State University, Corvallis, OR. He is an associate member of the ACI committees 222 and 365. His research interests include durability of concrete, corrosion assessment of different steel-concrete systems, and service life analyses.