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04791aam a2200517Ic 4500 001 F39BB95AB7CA11EC864CB83724ECA4DB 003 SILO 005 20220409010100 008 150529s2015 iauad fsbt s000 0 eng d 035 $a (OCoLC)910334760 040 $a UIG $b eng $e rda $c UIG $d SILO 088 $a IHRB Project TR-628 100 1 $a Schlorholtz, Scott M., $e author. $u Iowa State University. 245 10 $a Alkali Content of Fly Ash - Measuring and Testing Strategies for Compliance $c Scott M. Schlorholtz 264 1 $a Ames, Iowa $b Materials Analysis and Research Laboratory, Iowa State University $c 2015 300 $a xiii, 111 pages (129 pages in PD file) $b illustrations, charts (some color) 536 $a Performed by Iowa State University, Materials Analysis and Research Laboratory 536 $a Sponsored by the Iowa Department of Transportation, Iowa Highway Research Board $c IHRB Project TR-628 500 $a April 2015 -- Technical Report Documentation Page 504 $a Includes bibliographic references (pages 76-79) 520 3 $a Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise concern about the effectiveness of the fly ash to mitigate alkali-silica reaction (ASR). The available alkali test, which is commonly used to measure fly ash alkali, takes approximately 35 days for execution and reporting. Hence, in many instances the fly ash has already been incorporated into concrete before the test results are available. This complicates the job of the fly ash marketing agencies and it leads to disputes with fly ash users who often are concerned with accepting projects that contain materials that fail to meet specification limits. The research project consisted of a lab study and a field study. The lab study focused on the available alkali test and how fly ash alkali content impacts common performance tests (mortar-bar expansion tests). Twenty-one fly ash samples were evaluated during the testing. The field study focused on the inspection and testing of selected, well documented pavement sites that contained moderately reactive fine aggregate and high-alkali fly ash. A total of nine pavement sites were evaluated. Two of the sites were control sites that did not contain fly ash. The results of the lab study indicated that the available alkali test is prone to experimental errors that cause poor agreement between testing labs. A strong (linear) relationship was observed between available alkali content and total alkali content of Class C fly ash. This relationship can be used to provide a quicker, more precise method of estimating the available alkali content. The results of the field study failed to link the use of high-alkali fly ash with the occurrence of ASR in the various concrete sites. Petrographic examination of the pavement cores indicated that Wayland sand is an ASR-sensitive aggregate. This was in good agreement with Iowa DOT field service records. It was recommended that preventative measures should be used when this source of sand is used in concrete mixtures. 500 $a Catalogers note: This record is for the full-length report. A 2-page tech transfer summary is also available, at a link in this record. The summary is not cataloged individually. 516 $a Text file in PDF format. 538 $a System requirements: Adobe Acrobat, Adobe Acrobat Reader, or other PDF reading software. 538 $a Mode of access: World Wide Web 513 $a Final Report 650 0 $a Fly ash $x Portland Cement. 650 07 $a Alkali $2 trt 650 07 $a Alkali silica reactions $2 trt 650 07 $a Fly ash $2 trt 650 07 $a Materials $2 trt 650 07 $a Materials tests $2 trt 650 07 $a Potassium $2 trt 650 07 $a Portland cement concrete $2 trt 650 07 $a Sodium $2 trt 710 2 $a Iowa State University. $b Materials Analysis and Research Laboratory, $e performing body. 710 1 $a Iowa. $b Department of Transportation, $e sponsoring body. 710 1 $a Iowa. $b Highway Research Board, $e sponsoring body. 856 40 $a Iowa Publications Online $3 Online Access $z Full report $u http://publications.iowa.gov/id/eprint/19611 856 42 $a Iowa Publications Online $3 Online Access $z Tech transfer summary $u http://publications.iowa.gov/id/eprint/19611 856 40 $a DIgital Repository @ Iowa State University $3 Online Access $z Full report $u http://lib.dr.iastate.edu/intrans_reports/124/ 856 42 $a DIgital Repository @ Iowa State University $3 Online Access $z Tech transfer summary $u http://lib.dr.iastate.edu/intrans_techtransfer/76/ 941 $a 1 952 $l IAOX771 $d 20240710103048.0 956 $a http://locator.silo.lib.ia.us/search.cgi?index_0=id&term_0=F39BB95AB7CA11EC864CB83724ECA4DB 994 $a C0 $b UIGInitiate Another SILO Locator Search