2013 Session: 740

• New Developments in Selecting Chemical Treatments for Gravel Roads
  Abstract: There is an increasing need and interest in the use of chemical treatments to reduce maintenance and gravel replacement on gravel roads. However, choice of the most appropriate additive is difficult because of the proprietary nature of many of the additives available. This paper offers an updated selection guide, which is based on the practitioner understanding the roads that require treatment in terms of traffic, climate, geometry, and materials; understanding additive types and categories; and understanding the need to request potential vendors to categorize their additives accordingly. Based on the information collected, appropriate additive categories and if applicable, sub-categories, can be selected from two charts. The selection can be refined by evaluating expected performance using prediction charts that are based on material properties determined from simple, inexpensive laboratory tests.
  Authors: Jones, David
  Authors: Jones, David
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-2957
• Stiffness Evolution of Granular Materials Stabilized with Foamed Bitumen and Cement
  Abstract: From the literature it is possible to find two trends regarding the stiffness evolution of the Foamed Bitumen Stabilized/Recycled mixtures. The first trend indicates that once the foamed bitumen mix reaches a constant value due to curing process, the stiffness decreases with time due to load cycles. The second trend indicates that stiffness remains constant after curing process. In this research, the stiffness evolution of foamed bitumen mixes stabilized with different bitumen and cement contents is studied. The stiffness was measured using the Indirect Tensile Fatigue Test (ITFT). Results indicate that once the foamed bitumen mix reaches a constant value due to curing process, the stiffness will decrease or keeps constant depending on the stress-level applied to the foamed bitumen layer. If the stress-level is lower than a specific value, the stiffness of the mix will remain constant at a value very close to the initial stiffness. If the stress-level is greater than a specific value the stiffness of the mix will decrease gradually. Also, the reduction rate of the stiffness will be greater as the stress-level is higher. The analysis of results from mixes with different bitumen and cement contents allow identifying the effect of both stabilizing agents in the long-term stiffness.
  Authors: Halles, Felipe; Thenoux, Guillermo; Gonzalez, Alvaro Andres
  Authors: Halles, Felipe; Thenoux, Guillermo; Gonzalez, Alvaro Andres
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-4177
• Maintenance Cost Justification for Chloride Treatment and Aggregate on Unsealed Roads
  Abstract: Treating aggregate surfaced roads with chloride dust suppressants or building them up by adding good quality surfacing aggregate is generally believed to reduce surface maintenance costs by creating a more durable surface. This paper quantifies reductions in routine blade maintenance costs by analyzing nearly seven years of cost data from the Johnson County (Wyoming) Road and Bridge Department.Over the past decade, Johnson County has experienced considerable oil and gas drilling, substantially impacting the county’s aggregate surfaced roads. Initial analyses assess the expenditures on the county’s unsealed road network’s highest volume roads, with an average of around 350 vehicles per day and a very high proportion of heavy trucks. The average annual cost of $9,167 per mile per year [$5,696/km-yr] to maintain these roads is high for an unsealed road, but the traffic volume is also high. The county’s maintenance cost data was used to perform a regression analysis with the time since aggregate addition and the time since calcium chloride treatment along with traffic and precipitation as independent variables to generate a model that predicts routine blade maintenance costs. This model predicts cost savings as a percent of the initial chloride treatment cost. Savings range from 24% at 200 vehicles per day to 79% at 650 vehicles per day. This represents only part of the benefits from these treatments, since lower user costs, safer roads, environmental benefits, and lowered aggregate replacement frequency are additional but currently unquantified benefits from good quality aggregate and dust suppression.
  Authors: Huntington, George; Ksaibati, Khaled
  Authors: Huntington, George; Ksaibati, Khaled
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-1543
  Practice-Ready: Yes
• Design and Constructability of Emulsion-Stabilized Bases forFull-Depth Reclamation
  Abstract: Full-depth reclamation (FDR) of base courses with calcium-based stabilizers has been a common practice in many areas of Texas. Owing to its speed of operation and minimal lane closure period, asphalt emulsion has been recently used in a number of FDR projects in low volume roads as well. A few cases of premature failure of these stabilized bases primarily due to improper (or lack of) mix design or construction techniques led to a thorough evaluation and recommendations for an improved mix design and construction specification. The outcomes of a thorough evaluation of construction-related, material-related and environmental-related parameters that significantly impact the performance of emulsion-treated base materials were used to propose laboratory test procedures for mix design and guidelines for the construction of bases with emulsion. The practical aspects of this study that are incorporated in a trial specification are discussed in this paper.
  Authors: Nazarian, Soheil; Yuan, Deren
  Authors: Nazarian, Soheil; Yuan, Deren
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-2256
  Practice-Ready: Yes
• Maintenance Cost Justification for Chloride Treatment and Aggregate on Unsealed Roads
  Authors: Huntington, George
  Authors: Huntington, George
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-1543
• Design and Constructability of Emulsion-Stabilized Bases for Full-Depth Reclamation
  Authors: Nazarian, Soheil
  Authors: Nazarian, Soheil
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-2256
• New Developments in Selecting Chemical Treatments for Gravel Roads
  Authors: Jones, David
  Authors: Jones, David
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-2957
• Stiffness Evolution of Granular Materials Stabilized with Foamed Bitumen and Cement
  Authors: Halles, Felipe
  Authors: Halles, Felipe
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-4177