Performance of Concrete Overlays over Full Depth Reclamation

(c) 1036564Concrete overlays of full depth reclamation (FDR) are a pavement rehabilitation option involving reclamation of existing pavement layers while providing a new concrete surface to the roadway. This report reviewed nine concrete overlays of FDR that have been constructed in three states since 2006. Design and construction details were collected for each project and performance was analyzed through automated pavement condition data. Additional distress surveys and testing, including falling weight deflectometer (FWD) testing, were performed at one project in Freeborn County, MN, to further characterize the pavement condition and structural properties. Overall, the projects reviewed in this study were performing well to date, and concrete overlays of FDR appear promising as cost-effective, sustainable tools for helping agencies maintain their pavement network

Impacts of Internal Curing on the Performance of Concrete Materials in the Laboratory and the Field

Internal curing is a technique to prolong cement hydration by providing internal water reservoirs in a concrete mixture. These reservoirs do not affect the initial water-to-cementitious materials (w/cm) ratio, but do provide water for curing throughout the thickness of the element. Benefits of this approach include improved mechanical properties as well as reduced risk of moisture gradients, thus reducing the potential for warping. The aim of this work was to assess whether joint spacings could be increased in slabs containing lightweight fine aggregate (LWFA) as a source of internal curing

In Situ Cyclic Loading of Concrete Pavement Overlays Supported on Geotextile and Asphalt Interlayers: Buchanan County Road D-16

Automated plate load tests (APLTs) were conducted on County Road (CR) D-16 in Buchanan County, Iowa, to assess and compare the performance of unbonded concrete overlay test sections with three different geotextile fabric interlayers. The pavement was constructed in 2020. Field testing was performed on the asphaltic cement concrete (ACC) pavement prior to construction and then on the unbonded concrete overlay 2 months after construction and 1 year after construction. Cyclic and static APLTs were performed to assess the composite modulus and permanent deformation. Test results showed that the permanent deformation decreased by about 50 times after placing the PCC overlay over the ACC, both in sections with and without the geotextile interlayers. The composite resilient modulus values on the overlay increased about 10 times when compared to modulus values on the underlying ACC. Results indicated that the composite resilient modulus was still greater than 200,000 psi be decreased after 1 year along with increased permanent deformation in the control section (no geotextile interlayer). In the sections with a geotextile interlayer, the composite resilient modulus value increased 10% to 30% in two sections and decreased 10% in one section, while the permanent deformations increased by 30% to 60%. Results for the geotextile interlayer sections demonstrated better structural capacity than the control sections and monitoring of the load-deformation response of the pavement structure over time (3, 5, and 10 years after construction) is recommended