Concrete structures are still suffering from different types of distress such as cracking and deformation.
At present, the characterization of the concrete structures is implemented using two different concepts. The first
concept is based on performing laboratory-testing methods on prepared concrete specimens. In fact this concept
should be taken with great care and cautious. The second concept is based on conducting large scale testing
programs implemented directly on the structures. The main disadvantages of this concept are related to its failure to
measure the specified characteristics directly and they need back calculation to predict the required properties.
Secondly, they are large and expensive equipment. However, both concepts are not beneficial in predicting or
describing the mode of failure because they are macro-structural analysis based evaluation. Recently attempts were
made to use the Digital Image Analysis technique DIA to evaluate the aggregate gradation of concrete mixes. It is
believed that the application of the DIA technique should be extended to evaluate the microstructure characteristics.
The experimental program and DIA were carried out on 96 specimens. The compression and tension test were
carried out on 72 concrete cylinders made with three different mixes which contained gravel or dolomite as coarse
aggregate, and compacted either manually or mechanically. The DIA was implemented on 6 vertical sections and 18
horizontal sections. The results showed that the DIA is an effective technique to evaluate the performance, quality
and uniformity of concrete mixes. The results of the compression and tension were in a good agreement with the
results of the DIA. |
