The effect of initial steam curing and different types of mineral additives (Metakolin, Pumis, and Trass) on mechanical and durability characteristics of self-compacting concrete (SCC) was investigated and evaluated by various test methods. Concrete specimens were exposed to six different steam curing regimes after casting, namely two different temperatures (60, and 70 °C), and three total durations (16, 18, 20 hours). Results of surface electrical resis- tivity, and Rapid chloride penetration test (RCPT) for durability, and compressive strength for mechanical properties showed that exposing specimens to higher temperature could signiicantly improve compressive strength by promoting hydration. Keywords: compressive strength; initial steam curing; mineral additive; rapid chloride penetration test; self-compacting concrete; surface electrical resistivity. INTRODUCTION Self-Consolidating Concrete (SCC) was irst developed at the University of Tokyo, Japan 1 in order to reduce some construction problems; especially in urban regions where vibration for consolidation is not allowed. 2 Besides, due to little distances between bars in some structures, especially pre-tensioned bridges ordinary concrete may not spread all over the reinforcement bars. On the other hand because of trafic congestion which traps truck mixers, there is always need for maintaining slump for long distances. Hence, SCC can be categorized as high performance concrete due to its several abilities such as high lowability, passing ability through the work without any segretion and without any need of vibration because of adding water reducers (WR), and viscosity modifying admixtures (VMA), 3,4 while maintaining the ability to low more than ordinary concretes. Some projects have to be done in a short period of time, especially in urban regions. 5 The rate of concrete element production hence, plays an important role in the develop- ment of the whole project since molds have to be demolded as soon as possible. Therefore, SP-303-04 Effect of Steam Curing on Mechanical Properties of Self-Compacting Concrete Containing Pozzolan by Aliakbar Ramezanianpour, SeyedAli Ghahari, AmirMohammad Ramezaninapour, and Khashayar Esmaeili 45