Long term performance of stone interlayer pavement.

PDFTech Report01-1TAPavement performanceFlexible pavementsPavement interlayersStoneReflection crackingEvaluationLouisianaLouisiana Transportation Research CenterRasoulian, MasoodTiti, H. H.Martinez, MarkBecnel, ByronKeel, GaryLouisiana Transportation Research CenterLouisiana. Dept. of Transportation and DevelopmentLouisiana State University (Baton Rouge, La.)US Transportation CollectionThis report presents an evaluation of long-term performance of an alternative flexible pavement design referred to here as stone interlayer pavement. This alternative pavement design was introduced to reduce/defer reflective cracking experienced with soil-cement bases. The stone interlayer pavement design consisted of a 102 mm (4-in.) layer of crushed limestone base on top of 152mm (6 in.) of in-place cement stabilized base. The performance of the stone interlayer pavement was compared to that of the conventional pavement design for state highways other than the interstate system. The conventional pavement design consisted of 216 mm (8.5 in.) of cement stabilized base layer on top of lime treated subgrade. A 99 mm (3.5-in.) layer of hot mix asphalt concrete was placed over both pavement types.Stone interlayer and conventional pavements were constructed on state highway LA-97 (Acadia Parish) near Jennings, Louisiana. This highway is classified as low volume rural road with an average daily traffic of 2000 vehicles in 1991. Both pavements were monitored for 10 years after construction. During the evaluation period, pavement distress surveys, roughness, permanent deformation, and evaluation of pavement structural capacity using dynamic nondestructive testing were conducted. Additionally, as a part of the Louisiana Transportation Research Center (LTRC) accelerated pavement testing research program, both pavement designs were tested to failure under the Accelerated Loading Facility (ALF).The results of this investigation showed that the alternative stone interlayer pavement significantly reduced the amount of reflective cracking. The surface roughness measurements and pavement serviceability showed that the performance of the stone interlayer is slightly better than that of the conventional pavement. The structural capacity and rutting measured for both pavement types were similar during the evaluation period. On another scale, the accelerated testing results also verified the superior performance of stone interlayer pavement system. The cost analysis showed that the initial material cost of stone interlayer system might be as high as 20 percent more than that of the conventional pavement design. However, the stone interlayer pavement system showed superior performance over the standard soil cement pavement as tested under accelerated loading