Prediction of modulus of elasticity of FA concrete using crushing strength, UPV and RHN values

This paper presents the detailed experimental and analytical investigation on the evolution of static (Es) and dynamic modulus of elasticity (Ed) of concrete having 0%, 35%, and 50% FA used as partial cement replacement. Destructive and nondestructive tests were conducted on cylindrical specimens to evaluate the compressive strength and MoE of concrete in compression at the age of 28, 56, 90, and 150 days for all mixes. Experimental results show that the concrete having 35% FA achieved compressive strength and MoE similar to plain concrete at the age of 90 days, while 50% FA concrete attained satisfactory compressive strength and MoE at the age of 150 days. The comprehensive statistical analysis has been carried out in two ways on the basis of the experimental results. Firstly, the 28-day crushing strength of plain concrete in compression was used to design the models for the prediction of Es and Ed of fly ash concrete at any age and percentage replacement of FA. Secondly, using the values of UPV and RHN, models have been developed to predict the age or time-dependent Es and Ed of fly ash concrete. These models will be helpful in assessing the Es and Ed of fly ash concrete without knowing the 28-day crushing strength of plain concrete in compression in the laboratory. Hence, the suggested models in the present study will be beneficial in conducting the health assessment of fly ash based concrete structures.