A.T. VERMELTFOORT and E.WIJEN Technische Universiteil, Eindhoven

The accuracy of measurement of Electronic Speckle Pattern Interferometry (ESPI) is such that it is assumed the deformation of mortar in masonry joints can he determined. Deformations of uniformly distributed and partly loaded specimens were observed using ESPI and E moduli derived and compared with LVDT results. Detailed information was obtained from the observed surface of the specimen and effects of soft and weaker places on deformations were seen.