ASSESSMENT OF SELF COMPACTING CONCRETE PARAMETERS BY IMAGE ANALYSIS

Self-compacting concrete (SCC) with multi blended fiber reinforcement is widely used in earthquake zones.However, workability tests of the SCC are susceptible to human error and time consuming to assess.In this study, image analysis techniques are utilized to assess the filling ability, passing ability, and segregation resistance tests of SCC without human intervention.A steel frame is constructed to assemble two digital optic cameras with calibrated interior and exterior orientation parameters to obtain stereo images of the tested SCC.The flow radius of the SCC is detected by binarization with Otsu threshold method to eliminate any necessity of expert opinion to conduct the evaluation process.The flow time of SCC within 500 mm radius is detected by sampling 0.1 Hz frequent images.Moreover, the slump value is measured better than sub-millimeter accuracy by the help of stereo imaging.Duration of flow-through test from O-funnel or V-funnel is measured accurately by the developed stereo imaging technique and implementing binarization with Otsu threshold.The proposed system is also implemented for the assessment of L-type flow tester and measured the leveling time of the SCC more accurately than human.Furthermore, if the SCC specimen cannot reach the maximum level distance, the obtained level distance is also measured accurately.The maximum distance that SCC reached is detected by binarization with Otsu threshold then the stereo images are obtained and the position and height of the SCC is measured from the coupled binary images.The stereo camera is positioned to capture only the test apparatus with minimum background objects to ensure successful binarization.Pre-calibration of the optic images ensures correct matching of the overlapping ground points.Consequently, successful results are obtained from the laboratory tests.Automated assessment of SCC test can be helpful for SCC producers to evaluate the properties of their products correctly.