Strength development of concrete is slow with respect to the impressive improvements associated with rapid and serial production of concrete in construction technology in recent years. In this respect, the necessity of having concrete reach a desired strength level by accelerating its hardening process in as short a time as possible is inevitable. Various methods have been developed and applied to accomplish this purpose. Heat treatment has an extensive application amongst these procedures. Cement as a binder has a great importance in heat treatment application due to its function in providing concrete with hardening and gaining strength. The primary factors determining the behaviour of cements subjected to heat treatment are fineness and composition of Portland cements, the type and amount of additive used in blended cements, and cycle parameters. The technical and economical success of heat treatment application depends on the objective and application of a suitable heat treatment cycle. In this context, heat treatment parameters for five cements of different type and composition, which are commonly produced in most countries, were determined. It is concluded that a treatment temperature of 80 degrees C and a 4-hour initial curing before heat treatment is essential as well as reasonable for optimum heat treatment application to the cements investigated. (C) 1998 Elsevier Science Ltd.