Table 5. Spearman’s rank correlation of particle size and Adhesive Fracture Energy for Phase 2 results^§.

Particle Size Class	Spearman ρ for Correlation of %Particle Size Class with AdhesiveFracture Energy for SmoothOverlap Joints	Probability >|ρ|for SmoothOverlap Joints(n = 119)	Spearman ρ for Correlation of %Particle Size Class with AdhesiveFracture Energy for RoughenedOverlap Joints	Probability >|ρ|for RoughOverlap Joints(n = 79)
% CoarseSand	−0.1847	0.0443	−0.4583	<.0001
% MediumSand	−0.1705	0.0637	−0.3924	0.0003
% FineSand	−0.1033	0.2634	0.0191	0.8675
% VeryFine Sand	−0.0390	0.6738	0.3548	0.0013
% Silt andClay	0.1067	0.2480	0.6658	<.0001

^§Correlations calculated separately for roughened and smooth joints. Gum arabic only control joints (n = 10) were excluded from the calculations.