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dc.contributor.authorBowland, Adam Gregoryen_US
dc.date.accessioned2014-03-14T20:13:47Z
dc.date.available2014-03-14T20:13:47Z
dc.date.issued2011-06-27en_US
dc.identifier.otheretd-07082011-114623en_US
dc.identifier.urihttp://hdl.handle.net/10919/28229
dc.description.abstractThis dissertation presents the results of a study performed to investigate methods for increasing the damping capacity of concrete. A variety of additives, both particle and latex based, were added to standard concrete mixtures by replacing up to 20% of the fine aggregate to measure their effects on strength, stiffness, damping, and air content. The additives included rubber particles from recycled tires, calcium carbonate particles, styrene butadiene rubber (SBR) latex, and a commercially available product named ConcreDamp which contains vegetable gum suspended in styrene butadiene latex. An initial investigation resulted in the observation that all of the additives with the exception of the SBR latex would both increase air content and decrease compressive strength. As a result, combinations of additives were investigated to see if both the mechanical and dynamic properties could be improved. The addition of steel fibers to mixtures with ground rubber were found to significantly increase air content which offset any gains in compressive strength. The combination of ground rubber and latex was shown to improve both increase compressive strength and reduce air content. The study advanced to investigate the effects of rubber size on air content, strength, and damping. It was found that for the same volume of rubber, a larger rubber particle would decrease air content, decrease compressive strength, and improve damping. The results of this study show that the best performing additive was the vegetable gum latex which improved the concrete damping by a factor of 2 when added as 15% of the fine aggregate. Additionally, an equation is presented for calculating a strength reduction factor for concrete containing rubber particles of different sizes. Finally, two full scale footbridge laboratory specimens were tested to investigate the effect of increased material damping at the structural level. One footbridge was constructed using a base concrete mixture without damping admixtures. The second was constructed with a concrete mixture that contained a replacement of 15% of the fine aggregate with ground rubber. The results were used to create a finite element model in SAP2000 that was used to predict the effects that high damping concretes would have on the footbridge specimen.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartBowland_AG_D_2011_Permissions.pdfen_US
dc.relation.haspartBowland_AG_D_2011.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectDampingen_US
dc.subjectConcrete Admixturesen_US
dc.subjectRubberen_US
dc.subjectLatexen_US
dc.subjectCalcium Carbonateen_US
dc.titleComparison and Analysis of the Strength, Stiffness, and Damping Characteristics of Concrete with Rubber, Latex, and Carbonate Additivesen_US
dc.typeDissertationen_US
dc.contributor.departmentCivil Engineeringen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineCivil Engineeringen_US
dc.contributor.committeechairCharney, Finley A.en_US
dc.contributor.committeememberDowling, Norman E.en_US
dc.contributor.committeememberMurray, Thomas M.en_US
dc.contributor.committeememberWeyers, Richard E.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-07082011-114623/en_US
dc.date.sdate2011-07-08en_US
dc.date.rdate2011-08-01
dc.date.adate2011-08-01en_US


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