Abstract: The invention relates to a method of forming a pre-stressed concrete member in which at least a bonding surface of a pre-cast concrete shell has the hydration process therein temporarily arrested by means of heat applied thereto such that reactivation of the hydration process after the stressing of the shell and prior to the pouring into the shell of infilling concrete, results in a strong bond being formed between the bonding surface of the pre-cast concrete element and the infilling concrete. The construction joints between the infilling concrete and the pre-cast concrete shell are thus of an improved integrity.