Quantitative assessment of aggregate segregation of hardened self compacted concrete based on 2D image analysis

Self-compacting concrete developed as a material that does not need vibration for compaction has been increasingly being used in routine practice. Successful application of self-compacting concrete (SCC) is difficult to achieve due to increased flowability of the concrete mixture. Segregation of aggregate is one of the major problems during construction and ultimately influences the strength and durability of SCC. A fresh self-compacting concrete with poor segregation resistance can lead to a nonuniform distribution of coarse aggregates in the concrete volume, contributing to blockage of concrete flow, and nonuniform mechanical properties and durability at the hardened concrete. The article presents the unique method for quantitative assessment of aggregate segregation in hardened self-compacted concrete. A digital image analysis procedure using original lighting microscope equipment has been placed to investigate the concrete segregation behavior. The photographs of concrete specimen surfaces were taken to calculate measurements of aggregate volume in concrete. The research results showed that the originally developed attachment and unique aggregate segregation assessment method are useful in laboratory tests and could be used in the on-site application.