Quantifying the pavement preservation value of chip seals

To promote sustainability and optimize funding, state highway agencies are integrating pavement preservation strategies into the management of their roadway networks. Chip seals, a prominent pavement preservation alternative, are traditionally being used on low-volume roads with success in many states. However, as advancements in emulsion formulations continue and the use of chip seals on medium- and high-traffic facilities becomes more prevalent, there is a need to improve the methods to select and specify chip seal emulsions. The objective of this study was to develop an emulsion testing framework that captured properties related to critical distresses observed for in-service chip seals and considered the effects of traffic, environment, and aging. The proposed testing framework recommended the use of the dynamic shear rheometer and bitumen bond strength test to evaluate high-, intermediate-, and low-temperature performance. The testing protocols were applied to recovered and pressure aging vessel–aged emulsion residues from six emulsions widely used in Wisconsin, which included two emulsifier chemistries and two types of modification. The base binders before emulsification were also tested to assess the effects of the emulsification process. Results indicated that the proposed test methods could characterize material performance and differentiate between emulsion types and types of modification; however, additional research is needed to establish the relationship between laboratory-measured residue properties and performance of the full chip seal.

Download Full-text

Performance evaluation of fog seals on chip seals and verification of fog seal field tests

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2014-0340 ◽

2015 ◽

Vol 42 (11) ◽

pp. 872-880 ◽

Cited By ~ 5

Author(s):

Jeong Hyuk Im ◽

Y. Richard Kim

Keyword(s):

Significant Proportion ◽

Three Dimensional ◽

Field Tests ◽

Cost Effective ◽

Test Methods ◽

Pavement Preservation ◽

The North ◽

Chip Seal ◽

Highway Network ◽

Chip Seals

With an increasing emphasis on pavement preservation treatments due to economic concerns over the high costs of paving materials, one of the most cost-effective pavement preservation treatments, chip seals, now constitutes a significant proportion of the pavement preservation treatments used in the North Carolina highway network. To mitigate a major problem with chip seals, i.e., the loose aggregate particles, fog seals, which are composed of an emulsified product placed on top of the chip seal, can be used to help control the loose aggregate. For this study, fog seals were applied on top of newly fabricated chip. The surface texture of the fog-sealed chip seals was analyzed using the British pendulum test and a three-dimensional laser. Also, fog seal field test methods that were developed to suggest appropriate traffic opening times after fog seal construction were verified. The main findings presented in this paper are that: (i) the use of polymer-modified emulsions improves fog seal performance in terms of better aggregate retention and bleeding resistance; (ii) the skid resistance problems are not evident once the fog seal is applied on the recommended chip seal type; (iii) the relationship between skid number and mean profile depth can be determined based on three trends that are dependent on traffic loadings, and (iv) although the fog seal field tests were unable to be completed due to safety concerns, it can nonetheless be recommended that approximately 60 min after fog seal construction is an appropriate traffic opening time.

Download Full-text

Life-Extending Benefit of Chip Sealing for Pavement Preservation

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198121989721 ◽

2021 ◽

pp. 036119812198972

Author(s):

Farhang Jalali ◽

Adriana Vargas-Nordcbeck

Keyword(s):

Initial Conditions ◽

Survival Rates ◽

Single Layer ◽

Fatigue Cracking ◽

Time To Failure ◽

Multilayer Systems ◽

Pretreatment Condition ◽

Pavement Preservation ◽

Chip Seal ◽

Chip Seals

Chip seals are effective pavement preservation treatments that are usually applied to address non-fatigue cracking, weathering, and raveling, to seal the surface, to delay oxidation, and, finally, to improve skid resistance. This study used field performance data of test sections from the Pavement Preservation Group Study being conducted by the National Center for Asphalt Technology and the Minnesota DOT’s Road Research Facility. Data from test sections located in a low-traffic-volume road with a hot, wet, no-freeze climate collected over a period of 7 years were used to evaluate the effect of several chip seal treatments. Treatments range from single layer to multilayer systems, and include different construction techniques such as rejuvenating scrub seal and fiber membrane. Also, a section was crack sealed before the application of a single layer chip seal to assess the benefits. A semi-parametric survival analysis was performed to determine the differences in median time to failure (MTTF) for different chip seal sections versus a controlled section—representing a “do-nothing” scenario. The results showed that the MTTF for a single layer chip seal ranges from 6.8 to 9.1 years depending on the pretreatment condition. Crack sealing before chip seal could extend the MTTF by an additional 1–3 years, depending on initial conditions. Double and triple layer chip seals extend the MTTF beyond 10 years. Finally, the scrub seal provided the highest benefits, with survival rates close to 100% after 10 years of performance.

Download Full-text

Manual for Emulsion-Based Chip Seals for Pavement Preservation

10.17226/14421 ◽

2011 ◽

Cited By ~ 21

Author(s):

Scott Shuler ◽

Amy Epps-Martin ◽

Anthony Lord ◽

Denise Hoyt ◽

◽

...

Keyword(s):

Pavement Preservation ◽

Chip Seals

Download Full-text

Field Performance of Chip Seals for Pavement Preservation

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118768531 ◽

2018 ◽

Vol 2672 (12) ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Adriana Vargas-Nordcbeck

Keyword(s):

Functional Performance ◽

Good Condition ◽

Field Performance ◽

Pavement Preservation ◽

Dead End ◽

Pavement Deterioration ◽

Chip Seals ◽

Granular Base ◽

Heavy Loads ◽

Lane County

Over time, new pavements deteriorate due to the effect of traffic loads and the environment. If appropriate treatments are applied during the early stages of deterioration, it is possible to extend the service life of the pavement without incurring in costly rehabilitation or reconstruction activities. Chip seals are preservation treatments that can help protect the pavement structure, reduce the rate of pavement deterioration, improve skid resistance, and address minor surface problems. As part of the National Center for Asphalt Technology Pavement Preservation Study, chip seal test sections were placed in a low traffic volume road (Lee County Road 159) in Auburn, Alabama. The location consists of a two-lane county road that provides dead end access to a quarry and an asphalt plant, resulting in a high percentage of heavy loads. At the time of treatment, the existing pavement was 14 years old and consisted of a 5.5 in. hot-mix asphalt layer over a 6.0 in. granular base. Treatments were applied in the summer of 2012 and have been in service for approximately 4.5 years. During this time, cracking, roughness, rutting, and macrotexture data were collected weekly to evaluate pavement performance. The results determined that the performance of the treated sections is highly dependent on the initial condition of the pavement, particularly the percentage of area cracked. Pavements that are treated while still in good condition tend to remain in that category for a longer time. Macrotexture may also be used to evaluate the functional performance of the chip seals.

Download Full-text

Performance of Chip Seal Treatments in Two Different Climatic Regions

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198119853546 ◽

2019 ◽

Vol 2673 (12) ◽

pp. 728-736

Author(s):

Adriana Vargas-Nordcbeck ◽

Michael C. Vrtis ◽

Benjamin Worel

Keyword(s):

Cost Effective ◽

International Roughness Index ◽

Climate Conditions ◽

Pavement Preservation ◽

Climatic Regions ◽

Traffic Loads ◽

Pavement Deterioration ◽

Chip Seal ◽

Cost Effective Alternative ◽

Chip Seals

Over time, new pavements deteriorate because of the effect of traffic loads and the environment. Pavement preservation treatments, such as chip seals, are a cost-effective alternative for extending the service life of the pavement without incurring in costly rehabilitation or reconstruction activities. Chip seals are preservation treatments that can help protect the pavement structure, reduce the rate of pavement deterioration, improve skid resistance, and address minor surface problems. As part of the National Center for Asphalt Technology and Minnesota Road Research Facility Pavement Preservation Study, chip seal test sections were placed on low-traffic-volume roads in Alabama and Minnesota. The two locations were selected to represent different climate conditions. Lee County Road 159 in Auburn, Alabama, is subjected to warm, wet, no-freeze climate, while County State Aid Highway (CSAH 8) is located in a cold, wet, freeze area in Pease, Minnesota. Treatments have been in service for approximately 6 years in the southern sections, and 2 years in the northern sections. During this time, cracking, roughness, rutting, and macrotexture data were collected periodically to evaluate pavement performance. The results determined that cracking is a predominant form of distress for these treatments. While the treatments are not expected to address rutting or roughness, the results indicated little variation in the case of the southern treatments, and an increasing trend in international roughness index in the northern sections, likely related to the appearance of thermal cracking. Macrotexture data may be used to assess the functional life of the treatments.

Download Full-text