Along U.S. Route 23, north of Delaware, OH, five sections of concrete pavement were instrumented during the summer of 2007. All the properties and dimension of the concrete slabs in each section were held constant except for the aggregate size and the joint spacing. Section 390268, medium size coarse aggregate, section 390271, small size coarse aggregate, and section 390272, large size coarse aggregate were compared in order to determine the aggregate size that would improve the performance of the concrete slab.
Sections 390269, 13-foot joint spacing, section 390270, 15-foot joint spacing, and section 390271, 14-foot joint spacing were compared for same purpose. In addition, the relationship between axle spacing and joint spacing was studied. Section 390268 (medium aggregate) was found to have the least deflection and change in strains under environmental and dynamic loading. Section 390271 (large aggregate) exhibited the highest deflections. When the joint spacing was compared; section 3902269 (13-ft spacing) produced the least deflection, while section 390271 (14-ft spacing) produced the highest deflection. No correlation was found between the joint spacing and the axle spacing.