Materials Development and Characterization
ORITE is also fully equipped to test materials besides asphalt. These materials include soils, rock, aggregate, Portland cement concrete (PCC), water, and thermoplastics such as those used in drainage pipes.
For the WAY-30 project, the subgrade material underneath the pavement was subjected to grain size, Atterberg limit, Standard Proctor, maximum dry density, and resilient modulus measurements. The aggregate was passed through a sieve analysis and a resilient modulus test. Specimens of the PCC pavement on WAY-30 underwent these tests: unit weight, modulus of rupture, static modulus of elasticity, Poisson’s ratio, splitting tensile strength, compressive strength, maturity, and thermal coefficient of linear expansion. Specimens were tested after various lengths of curing to acquire data for a maturity curve. There were two mixes, and one of the mixes (Mix B, with fly ash additive) was cured following two approaches, one using a topical curing compound and the other using a water bath; the other mix incorporated ground granular blast furnace slag. The strength parameters were generally higher for the slag mix (Mix A) compared to those of the fly ash mix (Mix B). The curing compound on Mix B led to a 14% higher compressive strength initially, but the difference declined to 2% after a full 28 day cure.