A wide range of applications of ultrasonic testing of concrete is available, ranging from monitoring of setting behavior to studying damage behavior of concrete. This study deals with tracking strength development in concrete during early as well as later ages using ultrasonic methods. In this investigation, greater importance was given to amplitude of the ultrasonic through-transmission signals, than velocity. Ultrasonic signals were collected using an oscilloscope and the change in amplitude of the signal was analysed when concrete changed from fresh state to the hardened state. Energy curves, generated from the amplitude values, were used to compute the total energy passing through the concrete specimens, which in turn was empirically correlated with the compressive strength. Aging of concrete causes an increase in the amount of energy passing through concrete and this change was utilized to analyze strength development of concrete. In this investigation, a number of concrete mixes were studied with different dosages of mineral and chemical admixtures.