2013 Session: 285

• Evaluation of Reclaimed Asphalt Pavement Materials from Ultrathin Bonded Bituminous Surface
  Abstract: Ultra-thin bonded bituminous surface (UBBS), also known as Novachip, is a preventive maintenance or thin surface treatment that consists of a thin, gap-graded hot-mix asphalt(HMA) layer applied over a thick polymer-modified emulsion. The Kansas Department of Transportation (KDOT) has been using UBBS since 2002. However, some of these projects are now being rehabilitated. The objective of this study is to evaluate whether reclaimed asphalt pavement (RAP) materials from existing UBBS layers can be used in chip seal and Superpave mixtures. UBBS millings were studied with two different polymer-modified emulsions to assess their performance as precoated aggregates in chipseal. The ASTM D7000-04 sweep test was used to assess chip retention of UBBS millings. Three different mix designs were developed for both 12.5-mm and 9.5-mm nominal maximum aggregate size (NMAS) Superpave mixtures using a PG 70-22 asphalt binder and three different percentages (0%, 10%, and 20%) of reclaimed UBBS materials. The designed Superpave mixes were then tested for performance in terms of rutting and stripping using the Hamburg wheel tracking device (HWTD) and moisture sensitivity by the modified Lottman tests. Sweep test results showed that UBBS millings did not improve chip retention. Superpave mix design data indicated volumetric properties of Superpave mixes with UBBS millings met all requirements specified by KDOT. HWTD and modified Lottman test results indicated all designed mixes performed better with the addition of UBBS millings as RAP materials.
  Authors: Musty, Haritha
  Authors: Musty, Haritha
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-3060
  Practice-Ready: Yes
• Durability Assessment of Coarse Aggregates for Hot-Mix Asphalt in Maine
  Abstract: In this study, Micro-Deval and L.A. Abrasion were used to evaluate the durability of 72 individual coarse aggregates used for HMA in Maine. Aggregates used in hot-mix asphalt (HMA) must be durable and resistant to abrasion and degradation. Material loss in HMA pavements has recently been observed by MDOT and aggregate degradation has been hypothesized as a possible contributor. The Micro-Deval results showed no correlation with results from the L.A. Abrasion and the range in values was quite large. Two alternative methods of analyzing Micro-Deval were employed to measure the change in gradation of aggregate samples. A relatively large portion of tested aggregate sources were found to degrade significantly in the Micro-Deval test while having acceptable AASHTO Micro-Deval loss values, this presumably due to fracturing instead of abrasion. The weighted average method and area between curves method proved to be effective in measuring the change in particle size distribution not captured with the Method 1 Micro-Deval loss value. In addition, a significant influence of initial grading size was found in all of the Micro-Deval data with finer initial gradations producing higher loss values. The alternative analysis methods for Micro-Deval are recommended for use in detecting degradation not captured by the traditional Micro-Deval value.
  Authors: Nener-Plante, Derek
  Authors: Nener-Plante, Derek
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-2713
  Practice-Ready: Yes
• Improving the Properties of Reclaimed Asphalt Pavement for Roadway Base Applications Through Blending and Chemical Stabilization
  Abstract: Finding innovative ways to incorporate Reclaimed Asphalt Pavement (RAP) into highway base course applications will provide both environmental and economic benefits by allowing in situ recycling of material for projects such as widening or shoulder addition. RAP is a well-drained granular material, however 100% RAP has low bearing strength and creeps under load. The objective of this research was to develop methods to improve RAP’s strength while reducing creep to an acceptable level through blending with high quality crushed limestone aggregate and/or by chemical stabilization with asphalt emulsion or Portland cement. RAP/aggregate blends with and without chemical stabilization were compacted by modified Proctor method, cured, and tested for strength and creep. Strength was tested by the limerock bearing ratio (LBR), a variant of the CBR test. Specimens were tested dry and soaked to evaluate retained strength. One dimensional creep testing was performed using seven day oedometer tests. RAP/aggregate blends have the potential to be used successfully as base course material. Blends of RAP with 50% limerock (LR) base material attained acceptable LBR strength and creep with the addition of 1% of either asphalt emulsion or cement. Blends of RAP with 75% or more limerock attained close to acceptable LBR and low levels of creep without any chemical stabilizer. Significant variability was noted between results with different blends and stabilizing agents. Performance testing should be conducted to establish the suitability of a specific RAP/aggregate blend.
  Authors: Bleakley, Albert M.; Cosentino, Paul J.
  Authors: Bleakley, Albert M.; Cosentino, Paul J.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-2062
  Practice-Ready: Yes
• Development of Optimum Fractionation Method for High-RAP Mixturesby Sieve-by-Sieve Analysis of RAP Materials
  Abstract: The main objective of this research is to examine the effects that different methods of RAP stockpile fractionation have on the volumetric mix design properties for high-RAP content surface mixes, with the goal of meeting all specified criteria for standard HMA mix designs. To determine the distribution of fine aggregates and binder in RAP stockpile, RAP materials were divided by each sieve size. The composition of RAP materials retained on each sieve was analyzed to determine the optimum fractionation method. Fractionation methods were designed to separate the stockpile at a specified sieve size to control the amount of fine RAP materials which contain higher amounts of fine aggregates and dust contents. These fine RAP materials were used in reduced proportions or completely eliminated, thereby decreasing the amount of fine aggregate materials introduced to the mix. Mix designs were performed using RAP materials from three different stockpiles and the two fractionated methods were used with high-RAP contents up to 40% by virgin binder replacement. By using an optimum fractionation method, a mix with 40% RAP was successfully designed while meeting all Superpave criteria and asphalt film thickness requirement by controlling the dust content from RAP stockpiles.
  Authors: Shannon, Cory; Lee, Hosin; Tang, Sheng; Williams, Ronald Christopher; Schram, Scott Alan
  Authors: Shannon, Cory; Lee, Hosin; Tang, Sheng; Williams, Ronald Christopher; Schram, Scott Alan
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-5098
  Practice-Ready: Yes
• Improving the Properties of Reclaimed Asphalt Pavement for Roadway Base Applications Through Blending and Chemical Stabilization
  Authors: Cosentino, Paul
  Authors: Cosentino, Paul
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-2062
• Improving the Properties of Reclaimed Asphalt Pavement for Roadway Base Applications Through Blending and Chemical Stabilization
  Authors: Bleakley, Albert
  Authors: Bleakley, Albert
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-2062
• Durability Assessment of Coarse Aggregates for Hot-Mix Asphalt in Maine
  Authors: Nener-Plante, Derek
  Authors: Nener-Plante, Derek
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-2713
• Evaluation of Reclaimed Asphalt Pavement Materials from Ultrathin Bonded Bituminous Surface
  Authors: Musty, Haritha
  Authors: Musty, Haritha
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-3060