Kinetics and physico-chemical properties of alkali activated blast-furnace slag basalt pastes

الملخص EN

Granulated blast-furnaceslag(GBFS)isaby-productofthemetallurgicalindustryand consists mainlyoflimeandcalcium–magnesiumaluminosilicatesthatdefinedastheglassygranular material formedbyrapidcoolingofmoltenslagwithexcesswaterresultinginanamorphousstruc- ture.

Alkali-activatedslag(AAS)bindershavetakenagreatinterestfromresearchersduetoits manufacturing processwhichhasimportantbenefitsfromthepointofviewofthelowerenergy requirements andloweremissionofgreenhousegaseswithrespecttothemanufacturingofPortland cement.

Inthisstudy,GBFSwasreplacedby20,40and60wt.%ofbasaltactivatedby6wt.%of alkali mixturecomposedof1:1sodiumhydroxide(SH)andliquidsodiumsilicate(LSS)mixedwith sea waterandcuredin100%relativehumidityupto90days.Thephysic-chemicalparameterswere studied bydeterminationofsettingtime,combinedwatercontent,bulkdensityandcompressive strength.

Astheamountofbasaltincreasesthesettingtimeaswellascompressivestrength decreases whilethebulkdensityincreases.Thecompressivestrengthvaluesofdriedpastesare greater thanthoseofsaturatedpastes.ThehydratedproductsareidentifiedbyTGA/DTGanalysis, IR spectroscopyandscanningelectronmicroscopy(SEM