Abstract :
ThispaperpresentsanattempttoevaluatetheheattransferratesandgasreleaseratesintheCCIcore–concreteinteractionexperiments1–3,performedwithintheOECDMCCIproject.Anewmethodforcalculatingtheheattransferrateshasbeendeveloped.Itisbasedoncalculatingintegralsoftheconcreteenthalpieswiththehelpofpiecewiseexponentialinterpolationcurves.Thenewmethodtakesintoaccountheatconductionintheconcrete.Comparedtotraditionalmethods,thenewmethodgivesbetterresultsduringslowconcreteablation,anditstimeresolutionissignificantlybetter.Thegasreleaseratesfromtheconcretewerealsocalculated.Aregressionanalysiswasconductedfortheheattransfercoefficientsandgasreleaserates.Threecorrelationsforthebubbling-enhancedheattransferweredeveloped.Forthebasemat,asinglecorrelationcanbeusedforbothsiliceousandlimestone/commonsand(LCS)concretetypes.Forthesidewall,twodifferentcorrelationsareneededforthetwoconcretetypes.Withthesamesuperficialgasvelocity,theheattransferratetosiliceoussidewallsishigherthantoLCSsidewalls.Thissuggeststhatthereasonforthedifferentradialablationratesoftheconcretetypesobservedinthetestsisnotthelowergascontentofsiliceousconcrete.
