The effects of supplementary cementitious materials on alkali-silica reaction.

PDFTech ReportFHWA-KS-15-06SPR-73-1Alkali silica reactionsAggregatesFly ashAdmixturesCementPortland cement concreteEvaluationKansasKansas. Dept. of Transportation. Bureau of ResearchParcells, Jr., William H.Montney, Rodney A.Kansas. Dept. of Transportation. Bureau of ResearchUnited States. Federal Highway AdministrationUS Transportation CollectionThe Kansas Department of Transportation (KDOT) has controlled alkali-silica reaction (ASR) for more than70 years through the use of selected aggregates. Sand and gravel sources had to be tested using Kansas Test MethodKTMR-23 (1999), Wetting and Drying Test of Sand and Sand-Gravel Aggregate for Concrete. Those aggregatesources that did not pass the Wetting and Drying Test had to be used with a \ue2\u20ac\u153sweetener.\ue2\u20ac? The sweetener had to makeup a minimum of 30% (by weight) of the aggregate in the concrete. The most common sweeteners used have beenlimestone, calcite cemented sandstone, and a coarse gravel that passed the Wetting and Drying Test. Granite fromArkansas has recently been added as a sweetener in the Kansas City market.KDOT had traditionally banned Class C fly ash from concrete mixes due to their possible contribution to theASR problem. Class C fly ash that could not meet the expansion requirements for Effectiveness in Controlling Alkali-Silica Reaction in Table 3 of ASTM C618 (2005), Standard Specification for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in Concrete, was not allowed to be used in concrete mixes for KDOT projects.Test sections that utilized selected mixes from this study were placed during the summer of 2008 in WyandotteCounty, Kansas. The construction report for this project is available, and regularly scheduled surveys are beingperformed (Distlehorst, 2013).In 2007, KDOT specifications were changed to allow supplementary cementitious materials (SCMs) inportland cement concrete. KDOT began accepting ASTM C1567 (2004), Standard Test Method for Determining thePotential Alkali-Silica Reactivity of Combinations of Cementitious Materials and Aggregate (Accelerated Mortar-BarMethod), test results for concrete mixes containing SCMs. In 2009, the requirements of Table 3 of ASTM C618 werechanged from 100% of the control mix to 120% of the control mix for Class C fly ash used in all concrete.KDOT is currently evaluating threshold combinations of aggregates and SCMs to determine whichcombinations will require ASTM C1567 testing and which combinations can be approved without testing. Thisresearch is being conducted at the request of Kansas contractors due to the expense of the ASTM C1567 testin