tencriticizedasbeingtoovague,evenashavingnomeaningatall.SincethereisnosinglebestdefinitionforthematerialknownasHPC,itispreferabletodefineitasalowwater/binderconcretewhichreceivesanadequatewatercuring.HPCcanbemadewithcementaloneoranycombinationofcementandmineralcomponents,suchas,blastfurnaceslag,flyash,silicafume,metakaolin,ricehuskash,andfillers,suchaslimestonepowder.Ternarysystemsareincreasinglyusedtotakeadvantageofthesynergyofsomemineralcomponentstoimproveconcretepropertiesinthefreshandhardenedstates,andtomakehighperformanceconcretemoreeconomicalandecological.Fig.representsschematicallythefundamentalmicrostructuraldifferencebetweencementpasteshavinga.and.water/cementratio.Ina.W/Cratiocementpaste,therearemorecementgrainsandconsequentlylesswaterperunitvolumesothatcementgrainsaremuchclosertoeachotherthanina.W/Ccementpaste.Thismajordifferenceresultsinacompletelydifferenttypeof