摘要: |
Portland Cement Concrete Pavements (PCCP) with favorable as-constructed smoothness and lower rates of roughness progression are expected to have longer service lives. This study was done to estimate pavement damage due to dynamic wheel loads generated for various levels of roughness and also to quantify the effect of as-constructed smoothness and other design, construction, traffic, and climatic variables on the rate of roughness progression on concrete pavements in Kansas. Effect of concrete strength on estimated pavement damage was also studied. Selected inventory, construction, climatic, and annual roughness data were obtained for 21 PCCP projects constructed after 1992. From the annual roughness data in terms of International Roughness Index (IRI), collected by the South Dakota-type Profilometer, the rate of roughness progression was obtained through regression analysis . Multiple linear regression analysis was then done to find the functional relationships between the rate of IRI Roughness progression and the independent variables selected. The results show that the concrete modulus of rupture, subgrade material, number of wet days, and initial IRI roughness (roughness measured during the first year network-level survey after construction) significantly affect the rate of IRI roughness progression. Higher flexural strength tends to help retain as-constructed smoothness longer. Some pavements with high initial IRI roughness tend to become smoother as traffic passes over it presumably due to the smoothening of minor surface irregularities and stabilization of subgrade soil moisture during early years of pavement life. Permeable sub-base tends to decrease the rate of roughness progression. A trend analysis of annual IRI roughness data showed that the as constructed smoothness tends to wear out in about 3 to 5 years, and thus does not influence any future roughness development. The calculated dynamic wheel load has no definitive relationship with the roughness statistic, IRI. The dynamic wheel loads are rather functions of actual pavements profiles. The results of the damage analysis also indicate that neither pavement damage nor pavement life appeared to have any relationship with IRI. Concrete strength showed significant effect on pavement life. Higher strength concrete tends to have longer pavement life. Thus, use of high strength concrete is expected to result in PCC pavements with longer service life. Grinding reduces roughness on concrete pavements in the short term only. / NOTE: Final rept. Oct 98-Apr 02. / Supplementary Notes: Sponsored by Kansas Dept. of Transportation, Topeka. Bureau of Materials and Research. / Availability Note: Product reproduced from digital image. Order this product from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5285 Port Royal Road, Springfield, VA, 22161, USA. |