In summary, the practical ranges of the within-lab preci- sion estimates for Gsb determinations are reasonable for con- crete. However, for asphalt, the Gsb test result has a very large impact on VMA, one of the more critical criteria for asphalt mix design and acceptance. To reduce the impact on VMA to a tolerable level, the acceptable range of differences between within-lab replicates alternative methods would have to be less than 0.010, which is about one-third of what is currently practically attainable.