Advantages of using digital image correlation techniques in uniaxial compression tests

This paper discusses the advantages of using stereo vision imaging along with Digital Image Correlation techniques as an alternate data acquisition procedure in uniaxial compression testing of specimens that may include undetected internal defects before testing. The discussed techniques were implemented during an extensive experimental investigation at the University of South Carolina related to concrete material characterization in order to investigate inconsistencies in test measurements acquired through conventional instrumentation. The use of the proposed system in compression tests of concrete and rock specimens facilitated the accurate and efficient measurement of the modulus of elasticity of the materials based on full field strain measurements. Most importantly, however, the proposed system facilitated the assessment of the quality of the specimen and measurements, as these may be affected by internal material defects that do not show any evidence on the surface of the specimen before any testing takes place, or the deviation of the shape and size of the specimen from the specifications.