An experimental study on finding rheological properties of fresh conventional vibrated concrete mixes using concrete shear box

Rheological properties are based on material science approach and are necessary to overcome the deficiency of experimental tests such as slump test. In rheological method the flow characterisation of fresh concrete is described by two parameters namely yield stress and plastic viscosity (rheological properties). These parameters provide better understanding of concrete and enhance the quality of concrete thereby designing a more economical complex structure with improved construction processes. In the present study the rheological properties of low workability of fresh concrete with targeted slump varying from 0 to 50 mm are considered. Totally 12 different mixes were used with three varied cement contents of 300, 375 and 450 kg/m³ along with varying water contents of 115,130,145 and 160 lt/m³. The absolute volume concept is the basis for designing the concrete mixes. Totally 108 trials were considered with three varied shear rates of 5, 15, 25 mm/min and three varied normal stresses of 0.15, 0.25, 0.35 MPa. The results and observations reinforce the usefulness of concrete shear box as an additional instrument to find the rheological properties by making use of Bingham model as a static test with a low shear rate.