Cost effective prevention of reflective cracking of composite pavement : research project capsule.

755794630Research project capsule; Dec. 2008.PDFTech Report08-1PComposite pavementsGlass fiber reinforced concreteFiber reinforced concretePavement crackingLouisianaLouisiana Transportation Research CenterElseifi, MostafaLouisiana Transportation Research CenterLouisiana. Dept. of Transportation and DevelopmentLouisiana State University (Baton Rouge, La.)NTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and PerformanceNTL-HIGHWAY/ROAD TRANSPORTATION-MaterialsUS Transportation CollectionReflection cracks are caused by discontinuities (cracks or joints) in underlying layers, whichpropagate through a hot-mix asphalt (HMA) overlay due to continuous movement at the crackprompted by thermal and traffic loading. If the new overlay is bonded to the distressed layer,cracks in the existing pavement usually propagate to the surface within one to five years andeven as early as few months have been reported. Excessive seasonal temperature variationsand movements of a cement-treated base layer may also result in shrinkage cracking, whichextends to the pavement surface to cause reflection block cracks. Reflection cracking leads topremature failure of overlays by allowing water infiltration through the cracks, which causestripping in HMA layers and weakening and deterioration of the base and/or subgrade.Since the early 1930s, considerable resources and efforts have been spent to find new andrelatively inexpensive techniques to delay reflection cracking. Different methods, including theuse of interlayer systems (e.g., glassgrid, stress absorbing membranes, paving fabrics, etc.)and rubblization, have been suggested for enhancing pavement resistance to reflectivecracking. Experimental investigations of these crack control treatments indicate that theirperformances have been mixed and cannot be considered conclusive.Louisiana has experience with various techniques and treatments to control reflectioncracking since the 1970s; however, the cost-effectiveness and performance of these methodshave not been reliably evaluated. In addition, scientific evaluation and testing of thesetreatment methods was not performed on many projects. To ensure successful control of thisdistress and effective allocation of maintenance funds, there is a critical need to assess theperformance of pavement sections across the state built with various treatment methods andto determine the most cost-effective techniques to delay or to prevent reflection cracking incomposite pavements