CHARACTERIZATION OF MECHANICAL PROPERTIES AND VARIABILITY OF PCC MATERIALS FOR RIGID PAVEMENT DESIGN

Abstract

The FHWA-supervised Long-Term Pavement Performance (LTPP) project includes many experimental Special Pavement Studies (SPS) pavements from which concrete materials were sampled and tested for a variety of concrete mechanical properties. The materials and techniques used in constructing the SPS test pavements represent modern concrete pavement construction practices. The information collected includes compressive strength, flexural strength, split tensile strength, and static elastic modulus. The ages at which the specimens were tested for the various strength parameters ranged from 14 to 500 days. This paper describes an analysis of strength data from the LTPP SPS-2 experiment. The authors studied the rate of strength gain under the varied influences of climate/curing conditions, specimen type, and cement type. The variability of strength data obtained from a given project and the differences between “as-specified” and “as-built” strengths were also investigated. Both strength development and variability are important input parameters for pavement design and reliability analysis. Finally, commonly cited relationships between the various strength parameters were also analyzed. This paper provides typical concrete material inputs to the rigid pavement mechanistic-empirical design process.