Use of Infrared Thermography to Detect Thermal Segregation in Asphalt Overlay and Reflective Cracking Potential

2016 ◽  
Vol 28 (2) ◽  
pp. 04015118 ◽  
Author(s):  
Nirmal Dhakal ◽  
Mostafa A. Elseifi
Author(s):  
Pengyu Xie ◽  
Hao Wang

Reflective cracking is the major distress in composite pavement and can accelerate the deterioration of the whole structure. This paper analyzes the potential for reflective cracking in composite pavements because of thermal cycles. A heat transfer model was first developed to predict cyclic temperature variations with climatic inputs (solar radiation, wind velocity, air temperature, and humidity). Mechanical models were then employed to analyze thermally-induced reflective cracking potential using fracture mechanics parameters. Both models were validated through field measurement of temperature profile and crack propagation. The temperature profile in composite pavement can be predicted accurately from climate data and typical thermal material properties. Because of the temperature variation and gradient in composite pavement, concrete slabs undergo joint opening and curling deformation and stress concentration occurs at the bottom of the overlay. The loading cycles for initiation and propagation of reflective cracking were predicted by empirical equation and Paris’ law. Increasing overlay thickness can extend the pavement service life, but care is needed as different thicknesses offer varying efficiency. Thicker asphalt overlay mitigates reflective crack potential, especially at the crack initiation phase.


2020 ◽  
Vol 980 ◽  
pp. 244-253
Author(s):  
Chun Fu Zhu ◽  
Pei Feng Cheng ◽  
Guang Yu Zhao

The purpose of this study is to explore the forms and characteristics of reflection crack in asphalt overlay of old cement pavement, so as to provide reference for effective prevention and treatment of reflection crack.By means of ANSYS finite element software, considering the coupling effect of temperature and vehicle in different working conditions, the influence of cooling on asphalt overlay was analyzed, and the location and form of crack were discussed.The analysis results show that tensile crack and shear crack are more likely to occur near the joint of old cement pavement, and shear crack is more likely to occur in areas outside the joint, about 1/2 wheel length from the joint of cement pavement.The prevention and treatment of crack at different locations should be carried out according to different working conditions.


Author(s):  
Susan Tighe ◽  
Ralph Haas ◽  
Joseph Ponniah

Reflective cracking is a major and costly problem in many countries. It occurs in the top (overlay) layers above existing cracks in the lower (existing) pavement. This type of cracking can lead to premature deterioration of the pavement structure through the infiltration of moisture and debris. Although extensive research has been directed toward mitigation of the problem, work needs to be done, as it still appears to be a major problem. The problem is related in part to the fact that most of the work being done involves rehabilitation. One of the most common types of pavement rehabilitation is the use of an asphalt overlay. The focus of the present analysis is the economic benefits of reducing and treating reflective cracking before the placement of an asphalt overlay. A methodology for converting crack spacing to roughness is also presented. This information is used to examine how cracking is related to the measured international roughness index values. A model relating the amount of cracking to the loss of serviceability or a reduction in service life is presented. That model indicates that a reduction of transverse crack spacing from 5 to 20 m should result in a 5-year extension of service life, with a cost savings of $25,000 (2002 U.S. dollars) per two-lane kilometer. Measurement and treatment of cracking can also yield significant benefits. Benefit–cost ratios from the measurement of cracking can range from about 5 to 50, while proper and timely crack treatment (routing and sealing) can result in an extension of pavement life by 2 years and cost savings of $7,000 per lane kilometer.


2017 ◽  
Vol 2630 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Matheus S. Gaspar ◽  
Kamilla L. Vasconcelos ◽  
Amanda H. M. da Silva ◽  
Liedi L. B. Bernucci

Reflective cracking is a common issue with respect to rehabilitated asphalt pavements, especially when the rehabilitation is done by applying a hot-mix asphalt overlay on the existing damaged pavement. Several approaches can be adopted to delay reflective cracking. They include an increase of the overlay thickness and the use of a stress relief asphalt mixture (SRAM), which is a fine-graded, flexible, and thin asphalt interlayer. Because the efficiency of a SRAM is highly related to the properties of the asphalt binder used in the mixture, it is of interest to use a highly modified asphalt (HiMA) binder. This paper describes a field test comprising three sections at BR-116 (a heavily trafficked highway in Brazil). One of the rehabilitation strategies used for a cracked asphalt pavement was a 2.5-cm SRAM (produced with a HiMA binder) and 5-cm styrene–butadiene–styrene (SBS) hot-mix asphalt (HMA). The other two strategies were to apply SBS HMA overlays of different thicknesses (7.5 cm and 10.5 cm). The aim was to evaluate and compare the capability of these solutions to control reflective cracking. Rheological properties and multiple stress creep and recovery tests were performed on the asphalt binders, and the semicircular bending test was performed on the asphalt mixtures. The surface conditions were monitored, and the results for each section were compared. After a 29-month period, the section that received the interlayer had the lowest cracked area and showed better resistance than the overlays did to reflective cracking and better maintenance of the original thickness of the pavement.


2011 ◽  
Vol 217-218 ◽  
pp. 187-190
Author(s):  
Bin Yang ◽  
Qin Shou Huang ◽  
Xin Wang Qiu ◽  
Hua Xu

Partial wheel loading of the existing old cement concrete pavement joint will easily causes shear-type reflective cracking of asphalt overlay, which will cut down the service life of the pavement. This paper conducts an research on the changing rules of stress intensity factors of reflective cracking in asphalt overlay suffer dynamic loads. Choose 3 asphalt overlays with typical reflective cracking extend length of 1cm, 4cm and 8cm to investigate the impacts of parametric variation of vehicle speed, asphalt overlays thickness and modulus and stress absorbing layer on stress intensity factors of reflective cracking in asphalt overlays suffer singe-wheel dynamic loads. Results show that time history curves of dynamic stress intensity factors declines with the increase of structure-layer parameters; the maximum amplitude decreases as time goes on; the larger the structure parameter is, the faster the degradation is; and the vibration levels to gentle in the later half period, but stress intensity factors are not equal to zero in the last period of vibration, which shows that there exists residual stress intensity factors.


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