Characterization of viscoelastic joint sealants in concrete pavements /
Many different types of materials are used in concrete pavement joints to prevent water from entering through open joints and incompressibles from lodging in the joint reservoir. Silicone-based, two-part polymer and rubberized asphalt joint sealants have been characterized for their viscoelastic be...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739667381&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Many different types of materials are used in concrete pavement joints to prevent water from entering through open joints and incompressibles from lodging in the joint reservoir. Silicone-based, two-part polymer and rubberized asphalt joint sealants have been characterized for their viscoelastic behavior. These materials undergo large deformation and age under various environmental conditions in service. A series of relaxation tests were conducted. Specimens were artificially aged to different levels by exposing them to ultraviolet irradiance before testing. Five different ambient test temperatures ranging from -25 to 60'C and unit extension levels ranging from 5 to 100% were employed. It was found in this research that the relaxation modulus of each material was age, deformation and temperature dependent. The effects of time and temperature on the relaxation of a viscoelastic material under small deformation has been taken into account through the time-temperature principle. The WLF (Williams, Landel and Ferry) equation proposes a shift factor to relate temperature to time. The shift factor relationships similar to the WLF equation were also used to relate the deformation and age to time for these materials under finite deformation. Appropriate definitions of stress and finite strain were used to convert test data to a modulus curve. With shift factors for age, deformation and temperature, the relaxation modulus was satisfactorily expressed by a single "master relaxation curve." This master curve was then expressed in the form of a generalized Maxwell model in parallel. This model may be easily merged into a commercial finite element package for structural analysis through the use of Prony series. Bond strengths of the various joint sealants were also studied and a simple statistical model was derived to predict the adhesive bond strength of the sealant material. A number of factors such as aggregate type used in the pavement, surface preparation techniques and curing conditions were studied. Experimental results of the test factorial showed a significant influence of different variables on the bond strength. Fatigue tests were also carried out in order to predict the performance of the joint sealants. The performance equation suggested utilizes the bond strength, long term relaxation modulus, and strains caused by seasonal changes and traffic load. |
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| Item Description: | Vita. "Major Subject: Civil Engineering". |
| Physical Description: | xv, 157 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 119-121. |