Influence of Aggregate Properties on Concrete Mechanical Performance

Author(s)

Jussara Tanesi, Dale P. Bentz, Scott Z. Jones, Mengesha Beyene, Haejin Kim, Ahmad Ardani, Paul E. Stutzman

Abstract

While the influence of paste properties on concrete performance has been extensively studied, that between aggregate characteristics and concrete performance has not been investigated in detail. Based on previous research that demonstrated significant strength differences for two similar concrete mixtures, one prepared with limestone aggregates and the other with siliceous, a joint study between the National Institute of Standards and Technology (NIST) and the Federal Highway Administration (FHWA) was initiated to explore in detail the influence of aggregate source (and mineralogy) on concrete mechanical performance. Eleven aggregates of differing mineralogy were identified and obtained both for bulk characterization and for incorporation into two concrete mixtures. The first concrete mixture was based on a 100 % ASTM Type I/II ordinary portland cement, while the second consisted of a 60:30:10 volumetric blend of this cement with 30 % of a Class C fly ash and 10 % of a fine limestone powder. This latter sustainable mixture has exhibited exemplary performance in a previous study. This paper presents a limited portion of this study. The results show a wide variation in concrete performance amongst the different aggregates, with the range/average value for 28-d compressive strength being 32 % for the OPC concretes and 37 % for the ternary blend concretes. Several of the aggregate properties were found to have some influence on the concrete performance, but the extent of this effect depends mainly on the concrete property. Nevertheless, it appears that the greatest aggregate impact is how its modulus of elasticity relates to the paste modulus of elasticity. Data presented herein suggests that concrete performance is largely controlled by the level of bonding between aggregates and cement paste, a property that was only assessed in an indirect manner in the present study. Research using non-linear ultrasonic measurements to better assess this bonding is ongoing.

Citation

Journal of the Transportation Research Board

Pub Type

Journals

Keywords

Aggregate, bond, interfacial transition zone, modulus of elasticity, strength

Citation

Tanesi, J. , Bentz, D. , Jones, S. , Beyene, M. , Kim, H. , Ardani, A. and Stutzman, P. (1970), Influence of Aggregate Properties on Concrete Mechanical Performance, Journal of the Transportation Research Board (Accessed April 19, 2024)