A New Laboratory Evaluation Method for the Adhesive Performance of Crack Sealants

A New Laboratory Evaluation Method for the Adhesive Performance of Crack Sealants
Author: Xiaodi Hu
Publisher:
Total Pages: 7
Release: 2011
Genre: Adhesive performance
ISBN:

Crack sealing is a practice used for routine and preventive maintenance as part of a pavement's preservation strategy. However, crack sealant failures are common in Texas, particularly within the first 3 years of application (or service life). The major causes of sealant failures can be classified under two categories: Adhesion failure and cohesion failure. Although both failures can lead to a significant reduction in the service life of a pavement structure, adhesive failure is in most cases the dominant failure type. Several laboratory tests such as rotational viscosity, penetration, softening point, ductility, and bond tests are currently used to evaluate the properties of crack sealants. Among these tests, the bond test is specifically used to evaluate the adhesive failure of crack sealants and the procedure of the bond test is well documented in ASTM D5329-07. However, the bond test often takes several days to complete, and the pass/fail criterion is determined through visual observation, which is a very subjective process. Furthermore, the correlation between the bond test and adhesive failure performance of crack sealants in the field was found to be either weak or non-existent. In an attempt to minimize these problems, a simple, fast, and adhesive performance-related laboratory test method is developed in this paper to ensure the proper selection of a sealant for a given project.

Validation of Hot-Poured Crack Sealant Performance-Based Guidelines

Validation of Hot-Poured Crack Sealant Performance-Based Guidelines
Author: Imad L. Al-Qadi
Publisher:
Total Pages: 0
Release: 2017
Genre: Pavements, Asphalt
ISBN:

This report summarizes a comprehensive research effort to validate thresholds for performance-based guidelines and grading system for hot-poured asphalt crack sealants. A series of performance tests were established in earlier research and include the crack sealant bending beam rheometer (CSBBR), crack sealant direct tension test (CSDTT), the crack sealant adhesion test (CSAT), a rotational viscosity test, and a dynamic shear test. Validation was accomplished through an extensive field performance study incorporating a wide spectrum of commonly used sealants installed in eight test sites around the United States using two basic treatment methods: (1) clean and seal, and (2) rout and seal. Performance of these sealants and treatment methods were monitored for 3 years to quantify relative performance, primarily through adhesive and cohesive failures, as well as overband wear. Field samples were also collected from the sites to conduct laboratory testing to reflect in-service properties. A statistical method was used to develop correlations of the tests parameters with the field performance. The composite score approach, combining ranking and correlation, was used to develop a quantitative scale for determining the level of acceptance. Based on the composite score, a strong or acceptable correlation was obtained between field performance and laboratory test parameters. After the correlation between field performance and lab results was confirmed, the thresholds for test methods were selected or fine-tuned. An investigation was also conducted to evaluate the short-term and long-term aging effects of hot-poured crack sealants through a differential aging test. Rheological and mechanical properties of sealants at different aging stages were monitored to characterize the aging effects. Laboratory aging of sealants was studied using three different aging methods: kettle aging, melter aging, and vacuum oven aging (VOA). The aging index was used to evaluate the effect of these aging methods. By a comparison of the stiffness master curves obtained from the CSBBR test for field-aged samples and laboratory-aged samples, VOA was validated as a reasonable aging method for simulating 2 to5 years of field aging. The research proposes new guidelines for full implementation as AASHTO specifications. In addition to validated and revised thresholds for existing protocols, the research proposed a modified adhesion test and a simplified test for tracking resistance. Close inspection of the installation techniques and early performance feedback also supported the development of guidelines for crack sealant installation and application.

Validation of Hot-Poured Crack Sealant Performance-Based

Validation of Hot-Poured Crack Sealant Performance-Based
Author: Imad L. Al-Qadi
Publisher:
Total Pages: 67
Release: 2017
Genre: Pavements, Asphalt
ISBN:

This report summarizes a comprehensive research effort to validate thresholds for performance-based guidelines and grading system for hot-poured asphalt crack sealants. A series of performance tests were established in earlier research and include the crack sealant bending beam rheometer (CSBBR), crack sealant direct tension test (CSDTT), the crack sealant adhesion test (CSAT), a rotational viscosity test, and a dynamic shear test. Validation was accomplished through an extensive field performance study incorporating a wide spectrum of commonly used sealants installed in eight test sites around the United States using two basic treatment methods: (1) clean and seal, and (2) rout and seal. Performance of these sealants and treatment methods were monitored for 3 years to quantify relative performance, primarily through adhesive and cohesive failures, as well as overband wear. Field samples were also collected from the sites to conduct laboratory testing to reflect in-service properties. A statistical method was used to develop correlations of the tests parameters with the field performance. The composite score approach, combining ranking and correlation, was used to develop a quantitative scale for determining the level of acceptance. Based on the composite score, a strong or acceptable correlation was obtained between field performance and laboratory test parameters. After the correlation between field performance and lab results was confirmed, the thresholds for test methods were selected or fine-tuned. An investigation was also conducted to evaluate the short-term and long-term aging effects of hot-poured crack sealants through a differential aging test. Rheological and mechanical properties of sealants at different aging stages were monitored to characterize the aging effects. Laboratory aging of sealants was studied using three different aging methods: kettle aging, melter aging, and vacuum oven aging (VOA). The aging index was used to evaluate the effect of these aging methods. By a comparison of the stiffness master curves obtained from the CSBBR test for field-aged samples and laboratory-aged samples, VOA was validated as a reasonable aging method for simulating 2 to5 years of field aging. The research proposes new guidelines for full implementation as AASHTO specifications. In addition to validated and revised thresholds for existing protocols, the research proposed a modified adhesion test and a simplified test for tracking resistance. Close inspection of the installation techniques and early performance feedback also supported the development of guidelines for crack sealant installation and application.

Development of the Crack Sealant Adhesion Test

Development of the Crack Sealant Adhesion Test
Author: Xiaodi Hu
Publisher:
Total Pages: 46
Release: 2009
Genre: Pavements
ISBN:

Crack sealants are widely used in Texas to prevent water from entering into lower structural layers thereby extending pavement life. However, most current crack sealants have been reported to have a very short life mainly due to adhesive failures. Although adhesive failure is known to be the major failure mechanism very little attention has been paid to measuring this property in the laboratory. The main objective of this project was to develop a performance related adhesion test using TxDOTs Overlay Tester. In this report the crack sealant adhesion test protocol developed in year 1 of this study was finalized. The final test protocol includes a molding jig, a detailed sample preparation procedure, an adhesion test protocol, and criteria for interpreting the results. In this study 13 sealants (some of them have never been used in Texas) were evaluated following the proposed test protocol.

Accelerated Laboratory Evaluation of Joint Sealants Under Cyclic Loads

Accelerated Laboratory Evaluation of Joint Sealants Under Cyclic Loads
Author:
Publisher:
Total Pages: 18
Release: 2005
Genre:
ISBN:

The purpose of this research was to investigate and rank the performance of eight hot pour joint and crack sealant materials for applicability of use in Manitoba through a performance-based lab testing approach. The project involves laboratory testing of sealant materials to verify fundamental properties and performance simulation under cyclic loading. Sealants were tested using a repeated compressive and tensile fatigue test at +30 degrees C, 0 degrees C and -30 degrees C. For the covering abstract of this conference see ITRD number E211426.

Efficient Transportation and Pavement Systems: Characterization, Mechanisms, Simulation, and Modeling

Efficient Transportation and Pavement Systems: Characterization, Mechanisms, Simulation, and Modeling
Author: Imad L. Al-Qadi
Publisher: CRC Press
Total Pages: 924
Release: 2008-11-01
Genre: Technology & Engineering
ISBN: 0203881206

Internationally, significant attention is given to transport sustainability including planning, design, construction, evaluation, safety and durability of the road system. The 4th International Gulf Conference on Roads: Efficient Transportation and Pavement Systems - Characterization, Mechanisms, Simulation, and Modeling, hosted by the University o

Characterization of Crack Sealant Materials and Implementation Techniques

Characterization of Crack Sealant Materials and Implementation Techniques
Author: Mithil Mazumder
Publisher:
Total Pages: 340
Release: 2019
Genre: Pavements
ISBN:

Crack sealant materials are used to seal cracks early to reduce water infiltration and pavement repair. Crack sealant with high stiffness property is required due to the premature failure of sealant materials in cold weather. In order to put the sealant into the crack, crack sealing and filling technique has always been an important consideration to prolong the life of pavement. Crack sealing uses a router to cut the face of the crack to provide a uniform rectangular reservoir whereas filling is simply inserting sealant without performing any modification to the crack walls. For saving the cost of transportation agency, it is required to implement the best crack treatment techniques along with a new prospective crack sealant material. This research investigated the prospective of a new crack sealant material and its implementation techniques, and the objectives included: 1) investigating the rheology, cracking and microstructural properties of asphalt binder modified with SIS; 2) evaluating and comparing the field performance of crack treatment techniques in Texas; 3) investigating the best cost effectiveness practice between crack filling and sealing techniques; 4) quantifying the environmental impacts of crack filling and sealing treatment. The following conclusions were drawn based on the comprehensive laboratory and field investigation: 1) SIS modifier has the potential to be produced as a crack sealant material; 2) crack sealing treatment exhibited excellent performance and is observed to have on an average 37% more treatment effectiveness than crack filling treatment; 3) the highway design and maintenance program (HDM-III) and field cost input analysis showed that crack sealing can be more cost effective practice in a long run compared to filling technique; 4) although the initial environmental emissions of crack sealing treatment is higher compared to filling technique, this can be compensated along with an approximately 25% reduction in emissions by implementing crack sealing treatment over a long period; 5) implementing with proper guidelines crack sealing technique is more cost effective practice in a long run compared to filling technique.