Laboratory Determination of Maximum Theoretical Specific Gravity for Roller-Compacted Concrete

Roller-compacted concrete (RCC) has been used for many years in heavy-duty applications, and is gaining popularity in alternative applications, such as main-line roadway paving. During construction, density is the key parameter used to judge the quality of the RCC pavement. Density considerations are carried out in a number of different methods, although none currently utilize a laboratory measure of the maximum theoretical density of the designed mix. The primary goal of this research effort was to evaluate the determination of the theoretical maximum density of RCC according to the Rice method as given by AASHTO T 209 / ASTM D 2041. This measure was then compared to a number of other measures of density, including the calculated values of Theoretical Maximum Constituent Density (TMCD) and unit weight at zero air voids (ZAV). The results of the study indicate that the Rice method has promise as a test method that can be used during the design of RCC mixtures. It is believed that the theoretical maximum density should be determined in the laboratory during RCC mixture design. In addition, this value should be used as a basis for determining percent compaction during construction of RCC pavements.