CAIT project no.: 250-RU1991
Fiscal Year: 2009/2010
Rutgers-CAIT Author(s): Husam Najm, Ph.D., P.E.
External Author(s): Nazhat Aboobaker, NJDOT
Sponsor(s): New Jersey Department of Transportation
The New Jersey Department of Transportation Standard Specifications for Road and Bridge Construction require uniform quality-assurance testing and approval of concrete admixtures and structural steel paints. Testing is performed to insure that contract materials are not adversely modified or altered.
This study evaluates correlation coefficients for concrete admixtures and structural steel paints by performing IR scans using ASTM C494-05a specifications. The intent of this study is to perform a sufficient number of IR scans from different batches of the same sample as supplied by the manufacturer. These scans are then analyzed and average correlation coefficients for each sample are obtained.
Each admixture and steel paint will have its own correlation coefficient as determined by the corresponding scans. The correlation coefficients will be used to quantitatively evaluate and interpret the IR scans of job samples. A total of 23 commonly used concrete admixtures by NJDOT were tested. They include air-entraining agents, water-reducing agents, retarders, accelerating agents, and combinations of these agents as well as corrosion inhibitors.
In addition, a total of 28 structural steel paints used by NJDOT were tested. They include primary coats, secondary coats, thin films, and resins.
For concrete admixtures, the established correlation coefficients were the average values of a total of 12 scans from three different batches.
For steel paints, the established correlation coefficients were the average values of a total of 6 scans from three different batches. Few field samples of concrete admixtures were tested and their scans were compared with the established correlations. The study also includes an investigation of the effect of KBr types on correlations coefficients as well the effect of drying time of air-entraining admixtures on its correlation values.
The results of this study include methodology, test procedures, scan data, and correlation coefficients for quantitative assessment of the most commonly used concrete admixtures and structural steel paints on the qualified producer/supplier QPL NJDOT list.