Pavement Design and Materials Research 2003-2005 Activities

This report documents the workthat has been completed under the NDOT-UNR cooperative agreement for Pavement Design and Materials Research for the 2003-2005 time period

Evaluation of New Pavement Technologies in Nevada

This report documents the performance of new rehabilitation technologies of highway pavements in Nevada. A total of five new technologies were evaluated: four for flexible pavements and one for rigid pavements. The technologies evaluated include: cold in place recycling, crumb rubber modified mixtures, HMA overlays over concrete pavements, Hveem mixtures with PG-graded binders, and special asphalt binders. The performances of the various technologies were evaluated using the pavement management system (PMS) indicators as measured by the Nevada DOT on annual basis. The PMS performance indicators included: present serviceability index (PSI), rut depth (RD), fatigue cracking, thermal cracking, and block cracking. The performance indicators for each project were collected over its service life. The variations in the PSI, RD, and fatigue were then used to assess the successes or failures of the technology being evaluated. The data presented in this report showed that a) the cold in place recycling is an effective rehabilitation technique for Nevada's low and medium volume roads, b) crumb rubber modified mixtures do not represent a cost effective rehabilitation technique under Nevada's environmental, materials, and traffic conditions, c) HMA overlay over a deteriorating concrete pavement is an effective rehabilitation technique as long as the effective action of the concrete slab is broken tluough crack/seat or rubblization, d) the Superpave PG binder grading system alone is insufficient is evaluating the asphalt binders most commonly used in Nevada, namely polymer-modified binders, therefore, it is necessary to impose additional requirements on the Superpave PG grading system, d) some special binders performed excellent under Nevada's conditions such as polymer modified binders while other special binders such the Trinidad Lake blended binder did not perform well