TRB Annual Meeting Program

09-0275 - Performance of Three Popular Asphalt Pavement Rehabilitation Strategies
Session 679
This study analyzes the performance of three common hot mix asphalt rehabilitation strategies on 149 pavements over a period of seven years. All three strategies place two-inch overlays over the pavement to be rehabilitated. The first strategy includes an overlay on the existing pavement after sweeping the surface and applying a tack coat. The second strategy places the overlay after removing two inches of the existing pavement by cold milling. The third strategy places the overlay after treating the existing pavement using the heater scarification process. Performance was evaluated with respect to PG binder temperature range, traffic volume, overlay nominal maximum aggregate size, and climate. Data analyzed in the study was obtained from a pavement management system that is updated annually with respect to pavement condition. Results of this analysis indicate that two of the rehabilitation strategies perform approximately equal with one performing slightly better than the other, and both performing significantly better than the third. Polymer modified asphalts enhanced pavement performance depending on which rehabilitation strategy was utilized. Pavements were generally rehabilitated before reaching the zero service life threshold. However, when fatigue cracking was present in the original pavements, this was not the case. These pavements were rehabilitated at or above the zero remaining service life threshold. This indicates rehabilitation would have been warranted earlier in the life of these pavements. As a result, the expected life of the rehabilitation strategies utilized on these pavements may be shorter than could be expected had rehabilitation been done before distress reached this high level.
Scott Shuler, Colorado State University, scott.shuler@colostate.edu
Christopher Schmidt, Colorado State University

09-0825 - Methodology to Evaluate Quality of Pavement Surface Distress Data Collected from Automated Techniques
Session 679
Automated pavement data collection techniques are commonly used by highway agencies to collect pavement surface distress data at the network level. While an immense amount of data is collected at the network level, agencies realize that there is a lack of understanding in the quality of data that has been collected. Traditionally, either the overall pavement condition rating or individual distress ratings have been used to evaluate the quality of the condition data. However, each measure has its own pros and cons, rendering the use of a single measure inadequate. This paper presents a set of performance measures that can be used by highway agencies to quantify the quality of the collected and processed pavement condition data. The set of measures consists of (i) pavement condition rating and the hypothesis testing for differences; (ii) percentage cumulative difference in pavement condition rating over its entire range; and (iii) kappa statistics for individual distresses. This set of performance measures can be used to assess the effectiveness of an automated pavement condition data collection method and the effect of sampling on the pavement condition ratings obtained from automated techniques. Effectiveness of an automated technique is assessed against benchmark manual visual surveys. The performance measures offer a complete assessment of the effect of sampling on the overall pavement condition rating, its variation over the entire range, and the identification of individual surface distresses.
     Ghim Ping  Ong, Purdue University, ongr@purdue.edu
     A. Samy  Noureldin, Indiana Department of Transportation
     Kumares C. Sinha, Purdue University

09-1027 - Full-Scale Traffic Tests and Laboratory Testing Protocol for Determining Rapid-Setting Material Suitability for Expedient Pavement Repairs
Session 752
Numerous commercial-off-the-shelf (COTS) products have become avail¬able for small surface repairs in portland cement concrete (PCC) pavements that provide short set times, high early strengths, and good durability to withstand heavy loads. These materials have been used successfully for small repairs in the trans¬portation industry, and in industrial applications where the repair was less than 0.03 m3 (1 ft3). Applying these products for larger volume repairs while still achieving a trafficable surface within 3 hours of pavement repair has been a challenge. Experience gained from testing these products for full-depth repairs provides guidance for repair techniques that will expedite opening airfield or highway pavements to traffic and minimize the frequency of maintenance activities. An investigation conducted at the U.S. Army Engineer Research and Development Center (ERDC) in Vicksburg, MS examined 9 rapid-setting materials for repair of PCC pavements through laboratory characterization and full-scale traffic tests. Standard laboratory tests were performed to characterize the material properties over time and to provide a mechanism for assessing the material suitability for field repairs. Repairs with approximate volumes of 0.7 m3 (1.5 yd3) were constructed and evaluated under controlled traffic conditions to determine the ability of the repairs to support the 100 simulated passes of an F-15E aircraft within 3 hours of repair. Results of traffic tests identified 7 repair materials that met these criteria. A laboratory protocol for selection of rapid-setting materials was developed based on the laboratory and full-scale test results. This protocol will help prevent the selection of materials that are likely to perform poorly, therefore requiring extended traffic disruptions for additional repairs in the future.
     Lucy Phillips Priddy, U.S. Army Engineer Research and Development Center, lucy.p.priddy@usace.army.mil
     Sarah  Jersey, U.S. Army Engineer Research and Development Center
     Reed B. Freeman, U.S. Army Engineer Research and Development Center

09-1307 - Evaluation of LTPP Profile Data for Flexible Pavements
Session 679
The Long Term Pavement Performance (LTPP) program has collected longitudinal profile data for a wide variety of pavements nationally for almost 20 years. The program is managed by the Federal Highway Administration, which also maintains the LTPP database. Another portion of FHWA increased the testing frequency for longitudinal profile by state agencies for the HPMS from biannually to annually. This paper looks at the LTPP data to see if the increased frequency being required for HPMS is justified. The data sets used in the study were all General Pavement Studies (GPS) with either aggregate base or asphalt stabilized base. International Roughness Index (IRI) and the time between successful data collections were used to plot IRI versus time for each section. A polynomial of form ax2 + bx + c was fit for each site, and the polynomial was used to calculate the number of years to a 30 point change in IRI, using English units of inches per mile. Plots were also made of change in IRI versus the time between test events by climatic region. As has been reported by others, the largest contribution to future IRI is initial IRI. In all climatic zones, the time to reach a 30 point increase in IRI decreased with increasing initial roughness. Straight lines fit thru the change in IRI versus time between tests have very low slopes ranging from .0052 to .0096 points per day. Even at the maximum slope, it takes 3 years to reach a ten point change in IRI using English Units. Based on the LTPP data for GPS flexible pavements nationally, annual testing is not warranted.
Judith B. Corley-Lay, North Carolina Department of Transportation, jlay@ncdot.gov
Jeffery Mastin, North Carolina Department of Transportation

09-1564 - Use of Phosphoric Acid as a Modifier for Hot-Mix Asphalt
Session 541
The use of phosphoric acid to stiffen paving asphalt has become popular. Several premature paving failures have been attributed to its use, largely based on incomplete information. This has created uncertainty about the hidden pitfalls surrounding the use of this additive. The primary concerns are the effect of different grades of phosphoric acid, reaction with asphalt from different sources, accelerated aging of binders, increased moisture sensitivity and use with antistrip additives. This research seeks to address these issues. Data will be presented to show how the moisture sensitivity increases with increasing levels of acid modification. This is presented in terms of moisture being absorbed into binder and mastic samples as well as the leaching of phosphoric acid from gyratory specimens, a potential source of groundwater pollution particularly at high levels of acid modification. Preconceived notions about the use of phosphoric acid with alkaline antistrip additives and the effect on increased binder oxidation rates are also discussed. Phosphoric acid was found to not increase asphalt oxidation rates. Use with antistrip additives is perfectly feasible if the correct screening tests are conducted before use.
     Terence Stanley Arnold, Federal Highway Administration, terry.arnold@fhwa.dot.gov
     Susan P. Needham, SES Group & Associates
     John S. Youtcheff Jr., Federal Highway Administration

09-1913 - Measurement of Visibility Loss due to Splash and Spray: Comparison Between Porous Asphalt, Stone Matrix Asphalt, and Conventional Asphalt Pavements
Session 695
Road traffic accident is a major problem for the economy and society of ASEAN countries. In each year, road traffic accidents in Thailand cost millions of baht and inflict a large loss of life. Many of these accidents are caused by environmental or road conditions. Poor visibility on wet pavement is one cause of accidents. Accumulated water on wet pavement surfaces can create the “splash and spray” effect, resulting in visibility loss. The main objective of this study is to develop simple methods for measuring and comparing visibility loss between conventional dense-graded, Stone Mastic Asphalt (SMA), and Porous Asphalt (PA) pavements. Light Reduction Method (LRM) and Color Changing Method (CCM) were found to be the appropriate tests for visibility loss measurement. The test results from both LRM and CCM show that the visibility loss is significantly greater for conventional dense-graded pavement when comparing to SMA and PA pavements. It was found that the amount of water level, speed, and vehicle size significantly affect the visibility loss due to splash and spray. The models for predicting the percent of visibility loss was also developed and could be useful for the selection of pavement surface to reduce splash and spray under wet pavement conditions, and thus to improve road safety.
Pichaya Rungruangvirojn, Asian Institute of Technology, Thailand
Kunnawee Kanitpong, Asian Institute of Technology, Thailand, kanitpon@ait.ac.th

09-2283 - Evaluation of Warm-Mix Asphalt Produced with Double Barrel Green Process
Session 543
During the past three years, Warm Mix Asphalt (WMA) technologies from European countries have entered the North American market. European experiences with WMA technologies have indicated a significant reduction in mixture temperature, mixture viscosity, energy consumption and environmental emissions during asphalt mix production and placement in comparison with traditional hot mix asphalt (HMA). Based on North America experiences to date with these technologies, transportation agencies and HMA producers are unlikely to adopt WMA technologies solely for the reduction in manufacturing energy costs and environmental emissions, as these benefits do not cover the associated increase in investment and additive costs of WMA over HMA even in the most expensive North American energy markets. This paper presents an evaluation of the economic, environmental and mixture performance in order to assess the sustainability of WMA in North America. The paper examines the benefits, risks, investment and material costs, and sustainability associated with the different WMA technologies and specifically the Double Barrel® Green process. Included is an economic and mixture performance evaluation of WMA mixes containing reclaimed asphalt pavement (RAP) and manufactured shingle modifier (MSM™) produced with the Double Barrel® Green process during field trials in Vancouver, British Columbia.
Brent Middleton, Lafarge North America, Brent.Middleton@lafarge-na.com
Bob Forfylow, Lafarge North America

09-2520 - Application of Improved Crack Prediction Methodology in Florida's Highway Network
Session 679
With the growing need to maintain roadway systems amidst increasingly competitive resources while assuring safety and comfort for travelers, sound network-level decision-making becomes more vital than ever. A stochastic process known as Markov chain has been used extensively to capture the uncertainty associated with pavement performance over time and support this critical decision-making process. In applying Markov chain, this paper investigates the crack history of flexible pavements with an insight into the impacts of two primary factors contributing to the rapid deterioration of surface cracks in flexible pavements; excessive traffic loading and delayed maintenance and rehabilitation. Empirical results of the investigation are presented using the data from the Florida Department of Transportation¡¯s (FDOT) pavement condition survey database. The results show that the impacts of the above two factors are statistically different from one another in terms of the deterioration rate of Florida¡¯s pavements with respect to cracks. Hence the findings of this paper would assist the highway authorities in making more timely and efficient network-level decisions.
     Sahand  Nasseri, University of South Florida
     Manjriker  Gunaratne, University of South Florida
     Jidong  Yang, T.Y. Lin International, jidong_yang@yahoo.com
     Abdenour  Nazef, Florida Department of Transportation

09-2654 - Field and Laboratory Forensic Analysis of Reflective Cracking on Massachusetts Interstate 495
Session 295
In July 2007, the Massachusetts State Highway Department (MassHighway) began paving a pavement rehabilitation project involving placement of HMA over a section of Portland cement concrete (PCC) pavement on Interstate 495. The pavement rehabilitation consisted of a 50.0mm (2 inches) thick Leveling Course, followed by a 25.0mm (1 inch) thick Reflective Crack Relief Interlayer (RCRI), and then overlaid with another 50.0mm (2 inches) thick intermediate course consisting of a dense-graded hot mix asphalt (HMA) mixture that was identical to the Leveling Course. Due to time constraints on the project, approximately 30% of the PCC had only received the initial 50.0mm (2 inches) thick Leveling Course by the end of the 2007 paving season, with the remaining lifts scheduled for placement over the PCC in the Spring of 2008. Within approximately two months after placement, reflective cracking was observed in the area where only the initial 50.0mm thick Leveling Course had been placed. Approximately six months after the section that included the RCRI had been placed, reflective cracking was also observed. This paper summarizes a field and laboratory forensic effort that was aimed at determining the cause of the early reflective cracking on Interstate 495 in Massachusetts. Field testing, consisting of Falling Weight Deflectometer and coring of PCC pavement, were used to assess the PCC joint performance in the vertical and horizontal deflection modes. Laboratory testing was conducted on laboratory prepared HMA and evaluated for cracking resistance under vertical and horizontal deflections and test temperatures that simulated field conditions. The results of the study clearly indicated that the dense-graded HMA mixture used as the Leveling and intermediate layers could not withstand the vertical and horizontal deflections of the PCC joints taking place on I-495. This paper also provides a general framework that can be used to assess the compatibility that different HMA mixtures may have with RCRI mixtures when intended for use in composite pavements, which can be utilized for mixture selection/design prior to field placement.
     Thomas A. Bennert, Rutgers University, bennert@eden.rutgers.edu
     Michael  Worden, SemMaterials, L.P.
     Matthew  Turo, Massachusetts Highway Department

09-2693 - An Investigation of the Curing Mechanism of Foamed Asphalt Mixes Based on Micromechanics Principles
Session 543
This study investigated the curing mechanism of foamed asphalt mixes, based on which proposed standard curing procedures that are appropriate for use in project level mix design. Mixes with various asphalt and portland cement contents were subjected to two relatively extreme curing conditions, and multiple types of laboratory tests were performed. It was found that portland cement enhances certain properties of foamed asphalt mixes by strengthening the mineral filler phase, with the curing mechanism similar to that of normal cement treated materials. The curing mechanism of foamed asphalt mastic is primarily related to water evaporation. The bonding between asphalt mastic and aggregate particles cannot fully develop until most of the water retained at the interface evaporates. This bonding, once formed, is only partially damaged by reintroduced water. This mechanism was supported by direct fracture face observations on tested specimens. Two curing methods are proposed as standard procedures for project level mix design. The proposed strategy tests materials under two extreme conditions instead of attempting to precisely replicate field conditions, allowing the engineer to judge whether the tested materials suit the actual range of conditions at a specific project site. Portland cement or other appropriate active filler is recommended to be used in conjunction with foamed asphalt, which has a slow curing rate under most field conditions, to obtain early strength and allow early opening to traffic.
     Pengcheng  Fu, University of California, Davis, pfu@ucdavis.edu
     David  Jones, University of California, Davis
     John  Harvey, University of California, Davis
     Felipe  Halles, Pontificia Universidad Catolica de Chile

09-2946 - Development of Simplified Approach for Assessing Level of Safety of Highway Network Associated with Pavement Friction
Session 679
One of the most important indicators of level of service for a highway network is safety. Each year, thousands of motorists across North America are involved in motor vehicle collisions, which result in property damage, congestion, delays, injuries and fatalities. In Ontario, the Ministry of Transportation (MTO) is responsible for the maintenance and construction of approximately 39,000 lane-kilometres of highway. In 2004, the province estimated the value of the total highway system at $39 billion dollars. The MTO estimated that in 2002, vehicle collisions in Ontario cost the province nearly $11 billion. It also estimated that for every dollar spent on traffic management, 10 times that amount could be saved on collision-related expenditures, including health care and insurance claims. The safety of highway networks are usually assessed using various levels of service indicators such as ride quality (IRI), surface friction (SN), or number of collisions. This paper presents a simplified framework for assessing the level of safety of a highway network in terms of the risk of collision based on pavement surface friction. The developed safety framework can be used by transportation agencies (federal, state, provincial, municipal, etc.) or the private sector (consultants, contractors, concessionaires, etc.) to evaluate the safety of their highway networks and to determine the risk or probability of a collision occurring given the level of friction along the pavement section of interest.
     Amir  Abd El Halim, Stantec Consulting, amir.abdelhalim@stantec.com
     Susan Louise Tighe, University of Waterloo, Canada
     Tom  Klement, Ontario Ministry of Transportation, Canada

09-2973 - Storage Stability and Effect of Mineral Surface on Polyphosphoric Acid-Modified Asphalt Binders
Session 541
Polyphosphoric acid (PPA) is a commonly used modifier for asphalt binders. Successful modification of an asphalt binder with PPA is intended to improve the high temperature stiffness of the material without negatively affecting the low temperature properties. The overall mechanism of reaction between asphalt and PPA it is not very well understood, although it seems to be generally accepted that the PPA reacts with the asphaltene fraction of the binders. This study investigates two different asphalt binders, one with high asphaltene content, and one with low asphaltene content. The selected binders are modified with PPA and mixed with two different fillers to measure the rheological properties of both the modified and unmodified binders using the Dynamic Shear Rheometer. The surface area of the samples, the high-temperature storage time, the asphaltene content of the binders, and contact with mineral surface are all important factors examined in this study. By varying these parameters, the changes in rheological behavior of the liquid binder during storage are measured and analyzed. In addition, the effect of contact with mineral surface is investigated to reflect the possible interactions that could take place in asphaltic mixtures during processing and handling at high temperature. The results indicate that surface to volume ratio can have significant effects on aging of unmodified and modified binders. The PPA modification, however, can result in more stability during storage at high temperature. There also appears to be an important influence of contact with mineral surface on the changes in rheological properties induced by the addition of PPA.
     Codrin  Daranga, University of Wisconsin, Madison, daranga@wisc.edu
     Cristian  Clopotel, University of Wisconsin, Madison
     Adekunle  Mofolasayo, University of Wisconsin, Madison
     Hussain U. Bahia, University of Wisconsin, Madison

09-3157 - Practical Use of Multiple Stress Creep Recovery Test: Characterization of Styrene-Butadiene-Styrene Dispersion and Other Additives in PMA Binders
Session 541
The rheological properties of SBS modified asphalt binders (SBS-PMAs) depend on formulation variables. The most sensitive among them may be listed as polymer amount, cross-linking agent amount (%), and other additives (PPA). The dispersion of SBS in an asphalt binder depends on blending time and temperature and base asphalt binder compatibility. In this study an incompatible and a compatible base asphalt binder were selected and modified with various amounts of SBS. Elemental sulfur was used as a cross-linking agent in various proportions. Other additives such as PPA at 0.5% concentration and wax at various amounts were also used. High shear blends of SBS-PMAs were made in the laboratory by varying blending time until an optimum dispersion of polymer was obtained. The dispersion of the polymer was studied using a fluorescence microscope. MSCR test was used to study creep and recovery behavior of these modified binders. It was found that MSCR test results (Jnr and %recovery) were able to characterize the extent of dispersion of SBS in these PMAs. This implies that a fundamental test method is now available to discriminate between the ‘dump&stir’ type PMAs and those that have been optimally dispersed. This presentation discusses the effect of SBS dispersion and other additives on the MSCR test results.
John D'Angelo, Federal Highway Administration
Raj N. Dongre, Dongre Laboratory Services Inc., rajdongre@dongrelabs.com

09-3228 - Precision of AASHTO TP62-07 for Use in Mechanistic-Empirical Pavement Design Guide for Flexible Pavements
Session 778
In the Mechanistic Empirical Pavement Design Guide (MEPDG), one of the most important material inputs for designing flexible pavements is the dynamic modulus (E*). Currently, the American Association of State Highway Officials (AASHTO) has provided a provisional test specification for measuring the dynamic modulus of hot mix asphalt mixtures entitled, AASHTO TP62-07, Standard Method of Test for Determining Dynamic Modulus of Hot-Mix Asphalt (HMA). Under AASHTO TP62-07, recommendations are provided for sample preparation/compaction, measurement system, testing conditions/procedures and calculations. Unfortunately, information does not exist regarding the general precision of the test method. With so many different test machines capable of conducting AASHTO TP62-07 and the importance of dynamic modulus in flexible pavement design, an understanding of the general precision of the test method and its influence on the MEPDG is needed. This paper describes the results of a round robin study conducted to address the need for a precision-type statement for AASHTO TP62-07. Seven (7) laboratories, all having equipment compliant to the specifications in AASHTO TP62-07, were asked to laboratory age, compact, prepare, and test six (6) hot mix asphalt test specimens according to the provisions in AASHTO TP62-07. A statistical analysis was conducted on the test data in a precision statement environment. Based on the test results, an initial precision statement for AASHTO TP62-07 was generated and presented. The test results for the seven (7) different laboratories were also used as inputs in the MPEDG to evaluate the relative differences in predicted pavement distresses. Results from the precision evaluation were used to recommend modifications to AASHTO TP62-07 to promote greater precision among different testing laboratories and the results were re-evaluated in the MEPDG.
Thomas A. Bennert, Rutgers University, bennert@eden.rutgers.edu
Stacy Goad Williams, University of Arkansas, Fayetteville

09-3510 - Using the Dynamic Modulus Test for Moisture Susceptibility Evaluation of Asphalt Mixtures
Session 540
Stripping in Hot Mix Asphalt (HMA) is assessed by AASHTO T 283 using the indirect tensile strength test. The Tensile Strength Ratio (TSR) is used as the criteria for strength retention after sample conditioning. In recent years, the Dynamic Modulus E* test, conducted per AASHTO TP 62-03 has gained wider use in the pavement community. This is because it is a major input into the Mechanistic Empirical Pavement Design Guide (MEPDG), and is also being used as a simple performance test indicator. The objective of this study was to assess if the Dynamic Modulus E* laboratory test can be used as a replacement test property for the indirect tensile strength in AASHTO T 283. Since the E* test is non destructive, unlike the indirect tensile strength test, the advantage would be that the same specimens could be used before and after moisture conditioning. The scope of work in this research included conducting laboratory testing program on several types of asphalt mixtures using both test procedures. All of the mixtures were obtained from actual construction projects in the field. A unique aspect of this study is that some of the mixtures actually failed in the field by stripping. The E* tests were used to determine the percent retained stiffness, a term that was referred to as E* Stiffness Ratio, or ESR. Results of both TSR and ESR conducted on the same mixtures were compared and statistically analyzed. The analysis indicated that there was no statistical significant difference between the measured TSR and ESR values for the same mixture. The correlation obtained between the two ratios had good measures of accuracy. It was concluded that the ESR can potentially replace TSR testing to assess field moisture damage for asphalt mixtures. The recommendation was to continue with the testing program and expand the database for further future analysis.
     Atish Anil Nadkarni, Arizona State University, atish.nadkarni@asu.edu
     Kamil E. Kaloush, Arizona State University
     Waleed Abdelaziz Zeiada, Arizona State University
     Krishna Prapoorna Biligiri, Arizona State University

09-3683 - Forensic Investigation of Pavement Failures due to Moisture on Interstate Highways in Oregon
Session 295
In the last several years a number of major interstate and smaller projects in Oregon exhibited significant pavement distress that appeared to be associated with moisture damage within months following a rehabilitation activity. The premature failures prompted the Oregon Department of Transportation (ODOT) to fund a study to investigate interstate highway projects to determine the conditions and mechanisms that led to the premature failures. This paper documents forensic investigations of five Oregon interstate highway projects. Field investigations as well as laboratory testing of cores obtained from four of the five projects are documented. Improper tack coat or failure, permeable dense-graded layers, stripping, inadequate drainage, and, possibly, inadequate compaction of dense-graded material were identified as the likely root causes of the observed rutting problems on the projects that were investigated.
Todd Scholz, Oregon State University, todd.scholz@oregonstate.edu

Concrete Materials

09-0358 - Sustainable Concrete Through Reuse of Crushed Returned Concrete
Session 563
Every year, it is estimated that 2% to 10% (average of 5%) of the estimated 455 million cubic yards of ready mixed concrete produced in the USA (est. 2006) is returned to the concrete plant. The returned concrete in the truck can be handled in several different ways. A common approach is to discharge the returned concrete at a location in the concrete plant for processing (Figure 1). The hardened discharged concrete can be subsequently crushed by a crusher (Figure 2) and the coarser material can be reused as base for pavements or fill for other construction. However it is not easy to utilize the material finer than 2 inches (Figure 3). A research project was undertaken by the NRMCA Research Laboratory to study the use of crushed returned concrete, referred as Crushed Concrete Aggregate (CCA), as a portion of the aggregate component in new concrete. The project was funded by the Ready Mixed Concrete Research and Education Foundation (RMCREF). Demolishing old concrete structures, crushing the concrete and using the crushed materials as aggregates is not new and has been researched to some extent. This material is generally referred as Recycled Concrete Aggregates (RCA). However, RCA is different from CCA as construction debris tends to have a high level of contamination (rebar, oils, deicing salts, and other building components). CCA on the other hand is prepared from concrete that has never been in service and thus likely to contain much lower levels of contamination. The main objective of the research project was to develop technical data that will support the use of CCA from returned concrete by the industry and to provide guidance on a methodology for appropriate use of the material. Such a step can help the ready mixed concrete industry to save an estimated $300 million/year in operating costs. In addition, it will reduce landfill space by as much as 845 – 10 feet high football fields every year. The use of CCA could also help attain points under systems like the Leadership in Energy and Environmental (LEED) for certifying building projects for sustainable construction. This short article summarizes the key findings from the 20 month study. The complete reports can be downloaded from either one of the following locations http://www.rmc-foundation.org/newsite/index.htm and http://www.nrmca.org/research/eng_articles.asp.
Karthik Obla, National Ready Mixed Concrete Association, kobla@nrmca.org

09-0418 - Evaluation of D-Cracking Preventive Measures in an Ohio Test Pavement
Session 639
A test pavement located on part of State Route 2 near Vermilion, Ohio, was built in 1975 with sections designed to investigate the role of pavement design and materials variables that include aggregate source and size, subbase drainage systems, pavement joint design, subbase materials, joint sealants, cement, type of cure, and joint spacing on D-cracking. In 1998, this study was initiated to better understand concrete durability among the different composition variables of the pavement sections after 23 years of performance. This study established a methodology to analyze the pavement sections, gathered data, and analyzed the data using SAS statistical software. Significant findings on the variables affecting the performance of pavement sections were obtained. Key findings show the impact of aggregate source and size, joint sealants, and vapor barriers on pavement D-cracking performance and overall pavement performance. Based on the findings of this research, the requirement to use larger size aggregate in concrete pavement was incorporated into the Ohio Department of Transportation (ODOT) 1997 Construction and Material Specifications. Also, the 2009 ODOT specifications will eliminate the requirement for joint sealing in new concrete pavement based on in part on the findings of this study.
John Dryden, University of North Florida, j.dryden@unf.edu
L. Travis Chapin P.E., Bowling Green State University

09-1149 - Long-Term Chloride Penetration Resistance of Bridge Decks Made with Silica Fume Concretes
Session 718
With support from the Silica Fume Association, cores were obtained in 2001 and 2002 from four concretes from bridge decks in New York State and one in Ohio which were 15 years old and which had been exposed to de-icing salts. The bridge in Ohio was 15 years old and made with silica fume concrete (477 kg/m3 cementitious materials with 14.3% silica fume, 0.33 w/cm). The New York bridges included a 6 year old Portland cement concrete (0.42 w/c, 400 kg/m3), a 6 year old, 0.40 concrete with 20% F-fly ash and 6% silica fume (400kg/m3), a 7 year old, 11% silica fume, 0.37 concrete (455 kg/m3), and a 12 year old silica fume concrete overlay ( 6% silica fume, 0.40, 400kg/m3). The cores were tested for chloride penetration profiles using mm profiling, chloride bulk diffusion by ASTM C1556, rapid chloride penetration (ASTM C1202), and the depth of cover was noted, where visible. The results show that all of the silica fume concrete decks had high chloride penetration resistance, with all full depth decks having between 290 and 690 coulombs on average, while the portland cement concrete had 3900 coulombs. Predicted time-to-corrosion service life, using the Life-365 program, gave residual life estimates of between 30 and 61 years for the silica fume concretes. A portland cement concrete, used as a control, was found to be likely subject to corrosion at the time of coring. Predicted residual service lives based on extrapolation from existing chloride penetration profiles gave longer estimates by 10-years on average for the 3 new new bridges made using silica fume concrete.
     Robert Douglas Hooton, University of Toronto, Canada, hooton@civ.utoronto.ca
     Evan C. Bentz, University of Toronto, Canada
     Tony  Kojundic, Elkem Materials

09-2187 - Performance of Rigid Pavements Containing Recycled Concrete Aggregates: 2006 Update
Session 639
A 1994 field survey of pavements containing recycled concrete aggregates (RCA) constructed in Connecticut, Kansas, Minnesota, Wisconsin and Wyoming was undertaken. These pavements were resurveyed during the summer of 2006 to update their performance after being subjected to 12 more traffic years. Additional pavements made with RCA from Illinois and Iowa were also observed in 2006. Although the recycled pavements contain higher mortar contents, There was no clear correlation between recycled pavements higher total mortar content with cracking distresses in either survey, although one recycled pavement did exhibit more cracking than the control pavement. Overall there was little difference between the 1994 and 2006 surveys. Several pavements were rehabilitated by adding dowels for load transfer. These pavements are performing exceptionally well showing rehabilitation techniques normally applied to conventional concrete works effectively on recycled pavements. Laboratory evaluation of field cores showed 10 of the 16 pavements surveyed were found to have alkali silica reaction (ASR), possibly explaining why they were originally recycled. Eight of these pavements were shown to have significant remaining expansion potential and are expected to continue expanding. All pavements identified with ASR and D-Cracking showed field performance equivalent to their controls and pavements without distress. The recycled pavements have performed comparably with their controls. For instance, present serviceability rating (PSR) was found to be similar for the recycled and control sections. Likewise the recycled pavements that incorporated RCA derived from D-cracked and alkali-silica reactive (ASR) concrete appears to be performing at least equivalent to the original pavements. Keywords: recycled concrete aggregate, pavement performance, pavement recycling, concrete recycling, field evaluation, alkali silica reaction, d-cracking.
     David Lee Gress, University of New Hampshire, david.gress@unh.edu
     Mark  Synder, Consultant
     Jeffrey  Sturtevant, Whitney Bailey Cox & Magnani, LLC

09-2685 - Treatment of Structures with Alkali-Silica Reactive Distress with Lithium Nitrate: Case Studies
Session 639
Lithium compounds have been found to be effective in reducing expansion of small, ASR-affected laboratory specimens, but there have been little, if any, data showing that lithium compounds are effective in field applications. The research described in this paper aims to fill in this gap in knowledge and focuses on the treatment of ASR-affected structures in the United States. The findings of this study show that topical applications of lithium nitrate are ineffective in reducing ASR-affected due to a lack of penetration of the lithium solution. Vacuum impregnation of lithium in field structures was also found to be ineffective, again due to a lack of lithium penetration. Electrochemical methods of driving lithium compounds into were found to be quite effective in increasing lithium penetration, but the observed migration of sodium and potassium from within the concrete to the reinforcing steel may negate the effects of increased lithium penetration.
     Kevin J. Folliard, University of Texas, Austin
     Michael  Thomas, University of New Brunswick, Canada, mdat@unb.ca
     Benoit  Fournier, Natural Resources Canada
     Jason  Ideker, University of Texas, Austin
     Bradley  East, University of Texas, Austin

09-3855 - Can Soy Methyl Esters Reduce Fluid Transport and Improve Durability of Concrete?
Session 687
Many durability problems in concrete are caused by the transport of water or fluid containing aggressive ions. As a result, many seek to reduce the absorption and flow of fluids in concrete through the use of admixtures or topical sealants that refine or block pores. This paper presents results of a pilot study that evaluated the potential use of soy methyl ester – polystyrene blends (SME-PS) as both an admixture and/or a topical treatment. Results are presented for tests on the fresh properties, hardened properties, and transport properties of concrete containing SME-PS. Dramatic reductions in fluid absorption can be obtained with SME-PS, with little noticeable influence on set time, strength, or shrinkage. Eventually the application of SME-PS to concrete may have the potential to be used as a method to penetrate into the pore structure at saw-cuts and reduce long term damage. Keywords: soy methyl-ester, green building, fluid transport
     Kevin  Coates, Purdue University, kcoates@purdue.edu
     Samia  Mohtar, Purdue University
     Bernard  Tao, Purdue University
     William Jason Weiss, Purdue University

Construction

09-0357 - Design and Construction of Sustainable Pavements: Austrian and German Two-Layer Concrete Pavements
Session 243
There are a number of recent efforts in pavement research in the United States to create new sustainable technologies and designs using composite pavements—that is, pavements with heterogeneous asphalt and/or concrete layers resulting from new construction. While there are a number of asphalt-over-concrete composites in the United States, in the case of two-layer portland cement concrete (PCC) pavement very little American research and expertise exists its being a widely accepted solution for pavements in the European Union. This experience is described in this paper in terms of German and Austrian case studies. After a description of these case studies, the paper discusses major benefits of two-layer PCC, key factors for the success of two-layer PCC in the United States, and potential challenges in importing, adapting, and implementing German and Austrian techniques.
     Derek  Tompkins, University of Minnesota, Twin Cities, tompk019@umn.edu
     Lev  Khazanovich, University of Minnesota, Twin Cities
     Michael I. Darter, Applied Research Associates, Inc.
     Walter  Fleischer, STRABAG AG, Germany

09-1514 - Hot-Mix Asphalt Sampling Techniques and Methods of Acceptance: State Department of Transportation’s Practice
Session 594
Hot-mix asphalt (HMA) sampling is a critical step in quality control and quality assurance (QC/QA) programs to ensure that the tested material is representative of the installed product. Samples of HMA in Illinois are currently taken from a truck at the plant. This sampling method allows for a quick turnaround time since the QC laboratory is usually located at the plant. However, it may be difficult to obtain a representative sample since most of the sample is taken from the top of the pile and on the side closest to the sampling platform. In addition, this sampling method does not account for any additional asphalt absorption taking place during transportation and placement. The concept of moving the sample location to the job site offers the potential to address the weaknesses cited above. However, there are a number of different approaches, each with advantages and disadvantages. The objective of this study was to produce a review of successful methods and practices currently used to sample HMA during production and installation. This included visiting other states and collecting sufficient data to draw a final recommendation for the optimum technique to be adopted for HMA sampling in Illinois. The conclusion of the field visits is that sampling behind the paver is being successfully conducted by many states without difficulty. Based on the site visits conducted in this study, the roadway sampling procedure adopted by Michigan DOT was recommended for possible implementation in Illinois. In addition to this sampling technique, sealed bags adopted by Iowa DOT may be used, if necessary, to safely transport samples from the field to the laboratory.
     Mostafa A. Elseifi, Louisiana State University, elseifi@lsu.edu
     James  Trepanier, Illinois Department of Transportation
     Hal  Wakefield, Federal Highway Administration
     William  Pine, Heritage Research Group
     Abdul  Dahhan, Illinois Department of Transportation

09-1956 - Evaluation of Vacuum Drying for Determination of Bulk Specific Gravity of Hot-Mix Asphalt Samples
Session 594
Determination of bulk specific gravity (Gmb) of bituminous paving mixture is an important part of the Superpave mix design system and construction quality control/ quality assurance programs. Two problems commonly associated with AASHTO T 166 are the time it takes to dry test specimens and potential damage to the sample caused by drying at elevated temperatures. A vacuum drying technique has been developed to overcome these shortcomings. Field core samples and laboratory compacted samples of dense graded HMA and SMA were obtained for testing. The objectives of the study were to determine if dry mass and resultant Gmb of laboratory compacted and pavement core samples determined using vacuum drying procedures produces statistically similar results to AASHTO T 166 procedures. A second objective was to compare the dry mass obtained from AASHTO T 166 Method A to that of Method C. Comparisons of the means were made using ANOVA techniques along with paired t-testing. The practical significance of any statistically different results was also evaluated by using the precision statement of AASHTO T 166 (5). Results indicated that vacuum drying is an acceptable procedure for determining dry mass and bulk specific gravity of HMA samples.
Stephen Cross, Oklahoma State University, steve.cross@okstate.edu
Gyanendra Pokhrel, Oklahoma State University

09-2679 - Stiffness-Based Assessment of Pavement Foundation Materials Using Portable Tools
Session 512
Traditional pavement quality assurance has been performed using soil density and moisture content. Implementation of new mechanistic design methods calls for measuring the resilient modulus of constructed layers to determine if it matches the modulus used during the pavement design process. Several tools have been marketed for this purpose in recent years. Eleven soil test beds were constructed at the U.S. Army Engineer Research and Development Center (ERDC) to evaluate three of these tools. The study showed that the tools were simple to use and generally obtained repeatable results, but additional information regarding the true nature of the modulus measured by these tools is required to implement their use.
Sarah Jersey, U.S. Army Engineer Research and Development Center, sarah.r.jersey@usace.army.mil
Lulu Edwards, U.S. Army Engineer Research and Development Center

09-2825 - Dowel Alignment Constructability Evaluation In Portland Cement Concrete Pavements
Session 243
Although dowel bars are an essential design feature of jointed concrete pavements (JCP) to prevent pumping and faulting, limited studies that deal with the constructability of dowel alignment have been conducted. With the emergence of MIT Scan-2 as a non-destructive, robust method of locating dowels, it is now possible to efficiently evaluate construction quality of dowel bar placement, without damaging the newly constructed pavement. This paper presents a brief review of the results of recent field studies that are aimed at examining the constructability of doweled joints in concrete pavements. The dowel bar alignment data collected in this study encompasses a wide range of design and environmental conditions, and shows that alignment within reasonable levels, considering equipment, mix design, as well as workmanship and consistency is achievable in the field. Distress and performance analyses show that within these levels of misalignment, the pavement performance is not significantly affected. However, since construction errors are not uncommon, it is also reasonable to evaluate the effects of misalignments outside the typical tolerance limits. A comprehensive evaluation of the effects of dowel bar misalignment on pavement performance was conducted under NCHRP Project 10-69 to provide guidelines on dowel placement tolerance.
     Shreenath  Rao, Applied Research Associates, Inc., srao@ara.com
     Kyle  Hoegh, University of Minnesota, Twin Cities
     H. Thomas  Yu, Federal Highway Administration
     Lev  Khazanovich, University of Minnesota, Twin Cities

09-2891 - Development of a Decision Model for Selection of Appropriate Timely Delivery Techniques for Highway Projects
Session 240
On-time project performance is an important goal at the Oregon Department of Transportation (ODOT); pressure from two key constituents—the Legislature and trucking interests—creates even stronger focus on this goal. Currently, statistics indicate that less than 50% of ODOT projects complete within their originally contracted time of performance; further, project delay causes uncertainty about exactly when traffic delays may occur on a given stretch of highway, making it difficult to make the public aware of these delays far in advance. The primary “umbrella” method used to ensure on-time performance in standard ODOT contracting is liquidated damages. Often this amount is difficult to determine, so the assessment value is usually a matter of some judgment. In practice, liquidated damages are not seen as effective incentive and are rarely assessed. Other contracting and management methods which focus on encouraging time performance have been identified, but are used sporadically. Implementation of a system that creates better awareness of alternative schedule-delivery methods and that provides a consistent method for choosing among these methods would improve ODOT’s schedule performance. This paper discusses the results of a research project (ODOT SPR-646), designed to develop a means of selection among various available alternative methods for ensuring timely project delivery, given a specific project profile—using a selection model that is stable and scalable.
David N. Sillars, Oregon State University, david.sillars@oregonstate.edu

09-3357 - Methods for Evaluating Longitudinal Joint Quality in Asphalt Pavements
Session 594
Longitudinal joint quality is essential to the successful performance of hot-mix asphalt (HMA) pavements. Longitudinal joints have received a considerable amount of attention during recent years, as many state agencies are moving toward the implementation of longitudinal joint specifications. Most measures of joint quality are based on density determinations. However, distress at the joint is caused by the ability of air and water to enter the pavement structure – an action that is directly related to the permeability of the joint. In other words, density alone may not be sufficient for describing the quality of a longitudinal joint. The objective of this study was to identify the most appropriate test method (or methods) for describing HMA longitudinal joint quality. Three projects were selected for the study, and four testing stations were identified for each project. At each station, a number of test methods were performed at the longitudinal joint and to either side of the joint in order to assess the ability of each test method to properly discriminate between levels of joint quality. Multiple measures of density, permeability, and gradation were obtained at each testing station. Overall, the method providing the most accurate predictions of joint quality with the greatest level of discrimination was the CoreLok method for determining the bulk specific gravity of field cores. Thus, it was recommended that the CoreLok method be considered for the determination of field core density in the evaluation of longitudinal joint quality.
     Stacy Goad Williams, University of Arkansas, Fayetteville, sgwill@uark.edu
     Ashly  Pervis, University of Arkansas, Fayetteville
     Leela Soujanya Bhupathiraju, University of Arkansas, Fayetteville
     Annette  Porter, University of Arkansas, Fayetteville

09-3659 - Case Studies On Processes Involved In The Production And Placement Of High Rap Asphalt Concrete Mixes In 2007 On Selected Routes In Virginia
AFH60
This paper presents the documentation of Recycled Asphalt pavement processes in selected plants that were involved in the production of High RAP mixes for plant mix schedules which were placed in 2007 in the state of Virginia. A description of the processing of RAP at different plants is given and how the production of the high RAP material (reclaimed asphalt pavement which make up 20% or more of the asphalt mix) was monitored at the plants and the field on the selected routes in the state of Virginia. The types of asphalt plants operated by the different contractors are discussed showing how quality control process are monitored in High RAP production. Process control charts were shown for the RAP materials in one of the selected plants in addition to laboratory testing results. Results show the placement of the High RAP went well and field monitoring mechanisms are being put in the place to continue monitoring these sites for long term performance
     Alexander Kwasi Appea, VDOT, Alexander.Appea@VDOT.Virginia.gov
     Todd  Rorrer, VDOT
     Trenton  Clark, Virginia Department of Transportation

Design

09-2548 - Development and Validation of Methodology to Evaluate Unpaved Road Condition Based on Objective Distress Measures
Session 244
The condition of unpaved roads has been commonly assessed through qualitative distress measures. The relative effect of different defects over the road condition has not been considered consistently by some methodologies, or else, their application is limited to the conditions where they were developed. During 2007, the Ministry of Public Works of Chile (MOP) and a private consultant developed the study “Unpaved Roads Distress Models”. The scope of the study was to gain experience and understanding of unpaved roads behaviour. The main objective of the work presented in this document is the development and validation of a methodology to evaluate the condition of unpaved roads based on objective measures of distress, drainage and profile characteristics. The scope was to design a versatile tool, applicable to any location, following a simple procedure and under cost-effective survey techniques. The approach considered the development of condition models obtained from a questionnaire applied to a professional panel. The panel had to rate the condition of earth and gravel roads under different scenarios. These scenarios combined several levels of distress, drainage conditions and profile characteristics. The relative effect of each of these over the road condition was obtained from multiple linear regression analysis. Equations representing the Unpaved Condition Index (UPCI) and condition limits were developed for unbound gravel, stabilized gravel and earth roads, subject to three different climates (dry, Mediterranean and humid). UPCI equations and condition limits were validated successfully, resulting in a reliable and versatile methodology to assess unpaved roads condition.
     Alondra  Chamorro, University of Waterloo, Canada, machamor@uwaterloo.ca
     Hernan Eduardo de Solminihac, Pontificia Universidad Católica de Chile
     Mauricio  Salgado, APSA, Chile
     Ernesto  Barrera, Ministerio de Obras Públicas de Chile

09-3333 - Balancing Urban Driveway Design Demands Based on Stopping Sight Distance
Session 484
Many roadways located in urban areas, especially dense commercial areas, are subjected to on-street and adjacent off-street parking demands; however, local access via driveways is an essential component of these complex urban corridors. Vehicles entering and exiting these driveways and the interaction of these vehicles with parked cars, other moving motorized vehicles, bicycles, and pedestrians present challenges for a safe and efficient roadway corridor. The location and design of these driveways, together with parking and bicycle facilities, generate sight distance challenges that impact both pedestrians and bicyclists. This paper investigates the type and nature of impacts, including conflicts, sight distance, operations, and safety at driveway locations as they relate to pedestrians, bicyclists and drivers. The paper also analyzes appropriate design geometrics to provide adequate sight distance for safety at driveways with and without bicycle lanes. Parked vehicles often obstruct the driver’s view of legally approaching motor vehicles and bicycles. In many locations, vehicles exiting driveways must edge out into the active travelway before the driver has an unobstructed view. The driveway locations and design analysis demonstrates the value of bicycle lanes in providing enhanced sight distance. Current practices permit the longitudinal placement of on-street parking too close to driveways. For safety reasons, agencies should consider excluding on-street parking on roads with bike lanes when speeds exceed 30 mph so as to provide adequate sight distance without creating sporadic on-street parking spacing. Roads that do not have bike lanes present should exclude on-street parking when speeds exceed 25 mph.
     Karen K. Dixon, Oregon State University, karen.dixon@oregonstate.edu
     Ida  Van Schalkwyk, Oregon State University
     Robert Davis Layton, Oregon State University

09-3488 - Improved Sight Distance Model for Sag Vertical Curves with Overpasses
Session 435
On sag vertical curves uderpassing a structure, the fascia of the structure may cut the line of sight and limit the available sight distance. The current model of the American Association of State Highway and Transportation Officials (AASHTO) for symmetrical sag curves with overpasses is intended for overpasses that lie close to the point of vertical intersection (PVI) on long sag curves. This paper presents an improved model that provides the exact minimum sight distance (Sm) for any conditions, including non-centered overpasses and short sag curves that are typical in urban areas. The model explicitly includes as variables the overpass location, the overpass width, and the configuration of the first and second grades of the sag vertical curve. The model is formulated using mathematical optimization that involves an objective function and constraints. The objective function minimizes the available sight distance subject to constraints involving the geometry of the curve and the overpass. The model is spreadsheet-based and is solved using powerful optimization software. Application of the model was illustrated using some examples and the results show that the AASHTO model may underestimate Sm by10%–30%. A closed-form model for the minimum sight distance on single-arc asymmetrical sag curves is also presented for Sm > L. The proposed models provides a friendly, flexible, and accurate tool for sight distance analysis and should be of interest to highway designers and practitioners.
Said Easa, Ryerson University, Canada, seasa@ryerson.ca

Energy and Climate Change

Geology and Earth Materials

09-0537 - Performance of Pavement Aggregate Base Courses in North Carolina
Session 235
North Carolina DOT owns and maintains a system of 79000 miles, which range from interstate to very low volume roadways. The state is rich in quarries, and aggregate base course has been a mainstay of paving for roadways on new location for many years. This paper uses the pavement management system (PMS) data to evaluate the performance of three categories of aggregate base pavements based on the thickness of hot mixed asphalt placed over the aggregate base: thin, mid-range, and thick. Sections of pavement and their performance measures were pulled from the PMS by queries. Thin sections had asphalt thicknesses less than three inches. Mid-range sections had asphalt thicknesses of five to seven inches, and thick sections had asphalt thicknesses of more than nine inches. Aggregate base course thickness is generally eight inches, although six inches may be used on very low volume roadways. Aggregate thickness of 10 inches is common in the mountain region to avoid frost penetration into the subgrade. Performance curves, graphs of pavement condition rating versus time, were generated for each section or group of sections. A polynomial curve of form ax2 + bx + c, was fit to each curve and the time to reach a pavement condition rating (PCR) of 60 was calculated. Average, standard deviation, and histograms of the time to reach PCR of 60 was determined for each group. Time to PCR of 60 was highest for sections located in the coastal plain. The average times to PCR of 60 were 13.67, 15.2 and 14.03 years for the thin, mid-range and thick asphalt sections.
Judith B. Corley-Lay, North Carolina Department of Transportation, jlay@ncdot.gov
Jeffery Mastin, North Carolina Department of Transportation

09-1650 - Use of Structural Asset Management Measurements to Engineer Road Substructure Drainage Systems and Mitigate Climatic Effects on Roads
Session 238
Many areas in Western Canada have experienced increasing heavy commercial vehicle loadings primarily related to resource based economic development over the past three decades. Combinations of changing moisture conditions, marginal granular materials, and heavy loadings often lead to premature road structure disintegration or catastrophic failure. In particular, areas with slow moving and turning truck traffic can significantly increase the applied stress states and moisture pumping effects within the road structure, both at the road surface and deep into the road structure. Structural strengthening of roads to sustain severe heavy truck loadings often requires the installation of substructure drainage systems prior to placement of the structural strengthening system. However, explicitly measuring the initial design requirements and the life cycle performance of substructure drainage systems in terms of active drainage as well as impact on structural integrity is difficult based on traditional empirical based road structural evaluation and design methods. This report summarizes the use of a mechanistic based structural asset management approach to evaluate the performance of existing substructure drainage systems and to engineer the requirements of new drainage systems for urban and rural roads by describing three case studies. Based on the findings of these case studies, the use of falling weight deflection and ground penetrating radar to provide mechanistic based structural assessment measurements are effective to quantify the spatial limits of drainage systems accurately, as well as assess the end product structural asset value added of drainage systems.
     Curtis F. Berthelot Ph.D.,P.Eng., University of Saskatchewan, Canada, curtis.berthelot@usask.ca
     Brian  Taylor P.Eng., PSITechnologies Inc., Canada
     Erin  Stuber, PSITechnologies Inc., Canada
     Colin  Prang, University of Saskatchewan, Canada
     Brent L. Marjerison, Saskatchewan Ministry of Highways and Infrastructure, Canada
     Marty  Campbell, Red Deer County, Alberta, Canada
     Caroline  Jing, Red Deer County, Alberta, Canada

09-1843 - Three-Point Imaging Test for AASHTO Soil Classification
Session 474
A rapid digital image-based test has been developed for classifying highway subgrade materials by the AASHTO System. It relies on segregation of particles in a sedimentation column followed by determination of the elevations at which grains of size 2.0 mm (#10 sieve); 0.425 mm (#40 sieve); and 0.075 mm (#200 sieve) are found. Assuming that porosity variations through the column are insignificant as established in previous studies, the distances between these elevations translate to the percentages passing the various sieves. The method utilizes a previously developed calibration between an Image Wavelet Decomposition Index, CA and the Perceived Particle Diameter (PPD) in image pixel units. At a camera magnification of 32.5 pixels per millimeter, the entire grain size range from 2.0 mm to 0.075 mm is resolved. Thus, only a single fixed magnification lens is needed for the system. The paper demonstrates the accuracy of the new test through comparisons between the digital image-based results and conventional sieving for three soil specimens including a well graded sand, a uniform sine sand and a sandy silt. The advantages of the Three Point Imaging Test for AASHTO soil classification include reduced testing time, low noise, possibly lower equipment costs and elimination of airborne particles in the lab.
Roman D Hryciw, University of Michigan, romanh@umich.edu
Yongsub Jung, University of Michigan

09-3181 - Effects of Pavement Design on Frost Heave at MnROAD
Session 238
This paper presents the results of a study of the effect of different pavement design parameters on magnitude of frost heave, a major concern for pavements in cold climates. Elevations of frost pins embedded in MnROAD test sections measured over four years were analyzed, totaling to over 33,700 measurements used. Annual pin elevation changes were computed to evaluate the amount of frost heave and degree of frost heave uniformity within a cell. Statistical approaches such as visual analyses, Student-t hypothesis testing, and ANOVA analysis were used in this study to evaluate the effect of pavement design features on frost heave. The findings suggest that subgrade and base type, pavement thickness, and drainage capabilities are the major design factors that affect frost heave.
     Peter  Bly, University of Minnesota, Twin Cities
     Atika  Shamim, University of Minnesota, Twin Cities
     Lev  Khazanovich, University of Minnesota, Twin Cities, khaza001@umn.edu
     Randal  Barnes, University of Minnesota, Twin Cities
     Benjamin James Worel, Minnesota Department of Transportation

Infrastructure Preservation

09-0409 - Life-Cycle Cost Analysis of Surface Retexturing with Shotblasting as a Pavement Preservation Tool
Session 726
This paper explores the economics of replacing chip sealing and thin hot-mix asphalt overlays for highways with surface retexturing using the same shotblasting technology that is used on airport pavements. This technology is able to restores both the microtexture and macrotexture on pavements that have lost skid resistance due to polishing. An economic analysis of typical highway is conducted to determine the life cycle costs of using various options for the hypothetical project. The study utilizes the Federal Highway Administration pavement life cycle cost methodology and reports the results in Net Present Value basis to compare each skid restoration alternative. The analysis is conducted on two levels. First a traditional deterministic life cycle cost analysis is completed and it is followed by a stochastic analysis of life cycle cost using a Monte Carlo simulation. The paper concludes that shotblasting is an economically viable alternative to traditional methods for restoring lost skid resistance. It also allows the desired engineering objective to be achieved without the consumption of additional asphalt binder or aggregate thus making it an environmentally sustainable alternative as well.
Douglas D. Gransberg PE, University of Oklahoma, dgransberg@ou.edu

09-0659 - Chip Seal Maintenance: Solutions for Bleeding and Flushed Pavement Surfaces
Session 756
This report summarizes the findings of research directed at identifying maintenance solutions for bleeding and flushed pavements surfaced with a chip seal. Factors that contribute to bleeding and flushed chip seals include aggregate issues, binder issues, traffic issues, environmental issues, and construction issues. There is no better advice for dealing with bleeding and flushed chip seals than to avoid the problem from the outset by employing a preventive maintenance perspective. Bleeding is an immediate maintenance problem that must be addressed using corrective or in some cases, emergency, maintenance. The basic approaches used to treat bleeding include bridging over the liquid asphalt by applying aggregate of various types and gradations, cooling off the pavement surface by applying water with or without additives, or removing the bleeding asphalt and rebuilding the pavement seal. Flushing, in contrast to bleeding, is typically not a maintenance problem that must be addressed immediately. The basic approaches to treat flushed chip seals are to retexture the existing surface or to add a new textured surface over the flushed pavement. Three promising areas for further research and implementation relative to bleeding/flushing solutions include the use of lime water, the use of ultra high pressure water cutting, and the use of the racked-in seal at intersections.
William D. Lawson P.E., Texas Tech University, william.d.lawson@ttu.edu
Sanjaya P Senadheera, Texas Tech University

09-1857 - Georgia's Pavement Preservation with Micromilling and Thin Asphalt Overlay