Particle image velocimetry (PIV) to evaluate fresh and hardened state properties of self compacting fiber-reinforced cementitious composites (SC-FRCCs)

• Use of PIV for the fresh and hardened states analyses of concrete materials.
• Information regarding flow properties and behavior by using displacement vectors and strain fields.
• Load–crack width opening relations by using PIV and conventional methods.
• Observation of cracking and cracking patterns by PIV strain field analyses.

This paper presents the results of a comparative study of conventional techniques with an image based non-contact method, both to evaluate fresh and hardened state properties of self-compacting fiber-reinforced cementitious composites (SC-FRCCs). Experimental studies include measurement of mini-slump flow and mold flow test for fresh state and flexural strength, strain localizations and crack propagations for hardened state using both traditional measurement methods and a full field method called particle image velocimetry (PIV), which measures surface displacements and strains using digital image analysis. For mini-slump spread diameter measurements, camera recordings of the spread diameter of fresh mortar at regular intervals were taken and analyzed. The hardened state tests were carried out with un-notched specimens under four-point bending. Beams with 4 varying (beam depth/fiber thickness), “t/fL” ratios and 2 different fiber lengths were tested. During experiments, load–deflection, load–crack opening width curves and propagation of cracks were determined. The progressive opening of the cracks is studied using PIV, and continuous strain fields during cracking are provided. In addition, PIV technique was used to monitor the cross-sectional flexural strain distributions at midspan. Consequently, the results obtained by conventional methods were compared with the results obtained from PIV analyses. The main aim of the current study is to show the potential of PIV to evaluate some of the fresh and hardened state properties of SC-FRCC’s, in comparison with the traditional measurement techniques.