Evaluation of Actual Compressive Strength of High Strength Concrete by NDT

摘要

This paper deals with Non Destructive Testing (NDT) of High StrengthrnConcrete (HSC).rnAn experimental research was carried out, involving both destructive and nonrndestructive methods applied to different concrete mixes, with compressivernstrength varying from 30 up to 150 MPa. Both cubic and cylindrical standardrnspecimens and bigger blocks were cast.rnCorrelation curves were derived for different methods employed, as pulsernvelocity, rebound hammer, surface hardness, pull out, probe penetration,rnmicrocoring and combined methods.rnThe results shows good behaviour for some methods, like pulse velocity,rnsurface hardness and combined methods, also if new correlations are to bernestablished in some cases, respect to the ones already established forrnnormal concrete.rnSome problems arose for other methods, like pull out and probe penetration,rnfor which the available commercial testing systems appeared not adequate tornhigh strength concrete.