Title:
Impact of Under-Sulfated Cement on Concrete Performance: Detection and Mitigation Using Real-Time Slump Monitoring
Author(s):
Justin Dickey, Kevin J. Folliard, and Thanos Drimalas
Publication:
Materials Journal
Volume:
122
Issue:
5
Appears on pages(s):
95-106
Keywords:
flash setting; fly ash (FA); high-range water reducer; incompatibility issues; on-board slump-monitoring system (SMS); setting time
DOI:
10.14359/51749036
Date:
9/1/2025
Abstract:
This study investigates the impact of under-sulfated cement combined with high-calcium fly ash and lignosulfonate-based admixtures in ready mixed concrete, leading to rapid stiffening and delayed setting. Using an on-board slump-monitoring system (SMS) installed on a ready mixed concrete truck, significant increases in water demand were recorded to maintain target slumps, with mixtures showing minimal slump response to water additions. Laboratory tests, including isothermal calorimetry and mortar trials, confirmed the under-sulfated cement’s inadequate sulfate levels as the cause. Optimal sulfate addition was determined through calorimetry, and adjustments with gypsum effectively remedied rapid stiffening and delayed setting. This research demonstrates that an SMS can detect undesirable combinations of cement, fly ash, and admixtures in concrete, allowing real-time corrections. It underscores the importance of optimized sulfate levels in cement, particularly when using high-calcium fly ash combined with some high-range water reducers, to achieve desired concrete performance under varying field conditions.
Related References:
ASTM C109/C109M-23, 2023, “Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 50 mm [2 in.] Cube Specimens),” ASTM International, West Conshohocken, PA, 11 pp.
ASTM C150/C150M-22, 2022, “Standard Specification for Portland Cement,” ASTM International, West Conshohocken, PA, 9 pp.
ASTM C403/C403M-23, 2023, “Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance,” ASTM International, West Conshohocken, PA, 6 pp.
ASTM C494/C494M-19, 2019, “Standard Specification for Chemical Admixtures for Concrete,” ASTM International, West Conshohocken, PA, 15 pp.
ASTM C563-20, 2020, “Standard Guide for Approximation of Optimum SO3 in Hydraulic Cement,” ASTM International, West Conshohocken, PA, 8 pp.
ASTM C618-23, 2023, “Standard Specification for Coal Ash and Raw or Calcined Natural Pozzolan for Use in Concrete,” ASTM International, West Conshohocken, PA, 5 pp.
ASTM C778-21, 2021, “Standard Specification for Standard Sand,” ASTM International, West Conshohocken, PA, 3 pp.
ASTM C1702-23e1, 2023, “Standard Test Method for Measurement of Heat of Hydration of Hydraulic Cementitious Materials Using Isothermal Conduction Calorimetry,” ASTM International, West Conshohocken, PA, 9 pp.
Cost, V. T., 2006, “Incompatibility of Common Concrete Materials – Influential Factors, Effects, and Prevention,” HPC: Build Fast, Build to Last: The 2006 Concrete Bridge Conference, Reno, NV, 24 pp.
Detwiler, R. J., and Shkolnik, E., 2005, “Something Uncommon: New Admixtures, Supplementary Materials Lead to One Problem – Incompatibility,” Roads and Bridges, V. 43, No. 1, Jan., pp. 30-32.
Helmuth, R.; Hills, L. M.; Whiting, D. A.; and Bhattacharja, S., 1995, “Abnormal Concrete Performance in the Presence of Admixtures,” PCA R&D Serial No. RP333, American Cement Association, Washington, DC, 94 pp.
Hills, L., and Tang, F., 2004, “Manufacturing Solutions for Concrete Performance,” IEEE-IAS/PCA 2004 Cement Industry Technical Conference, Chattanooga, TN, Apr., pp. 121-130.
Johnson, C. D., 1987, “Admixture-Cement Incompatibility: A Case History,” Concrete International, V. 9, No. 4, Apr., pp. 51-60.
Khalil, S. M., and Ward, M. A., 1978, “Influence of SO3 and C3A on the Early Reaction Rates of Portland Cement in the Presence of Calcium Lignosulfonate,” American Ceramic Society Bulletin, V. 57, No. 12, Dec., pp. 1116-1122.
Lashley, L., 2009, “The Compatibility and Performance of Cementitious Materials and Chemical Admixtures,” MASc thesis, Department of Civil Engineering, University of Toronto, Toronto, ON, Canada, 185 pp.
Lee, C. H., and Hover, K. C., 2016, “Early-Age Stiffening of Paste, Mortar, and Concrete in Lab and Field,” ACI Materials Journal, V. 113, No. 1, Jan.-Feb., pp. 83-93. doi: 10.14359/51687917
Lerch, W., 1946, “The Influence of Gypsum on the Hydration and Properties of Portland Cement Pastes,” Proceedings of the American Society for Testing Materials, V. 46, pp. 1252-1292.
Meyer, L. M., 1976, “Effect of Admixtures on Cement Performance in Concrete,” 1976 Cement Chemists’ Seminar, American Cement Association, Washington, DC, 11 pp.
Niemuth, M. D., 2012, “Effect of Fly Ash on the Optimum Sulfate of Portland Cement,” PhD dissertation, Purdue University, West Lafayette, IN, 506 pp.
Ramachandran, V. S., ed., 1995, Concrete Admixtures Handbook: Properties, Science, and Technology, second edition, Noyes Publications, Park Ridge, NJ.
Roberts, L. R., 1995, “Dealing with Cement-Admixture Interactions,” 23rd Annual Convention of the Institute of Concrete Technology, Institute of Concrete Technology, Sandhurst, Berkshire, UK, 15 pp.
Roberts, L. R., and Taylor, P. C., 2007, “Understanding Cement-SCM-Admixture Interaction Issues,” Concrete International, V. 29, No. 1, Jan., pp. 33-41.
Sandberg, P. J., and Roberts, L. R., 2005, “Cement-Admixture Interactions Related to Aluminate Control,” Journal of ASTM International, V. 2, No. 6, June, pp. 1-14. doi: 10.1520/JAI12296
Taylor, P. C.; Graf, L. A.; Zemajtis, J. Z.; Johansen, V.; and Kozikowski, R. L., 2006, “Identfiying Incompatible Combinations of Concrete Materials: Volume I-Final Report,” Federal Highway Administration and Portland Cement Association, Skokie, IL, 159 pp.
Taylor, P. C., 2007, “Concrete Material Incompatibility-Predicting and Preventing Pavement Mix Problems,” The Construction Specifier, V. 60, No. 1, pp. 46-53.
Wang, H.; Qi, C.; Farzam, H.; and Turici, J., 2006, “Interaction of Materials Used in Concrete,” Concrete International, V. 28, No. 4, Apr., pp. 47-52.