Abstarct: Improvement of concrete structures with the attention on strength and durability, on the other hand, lack of professional worker and growing expansion of prefabricated concrete structures made the production of concrete necessary to produce a concrete with no need to vibrate to consolidate. Use of pozzolan as a replacement of cement in concrete not only would reduce the usage of cement, energy and production of greenhouse gases but also it would benefit concrete with increasing compressive strength and reducing permeability. Furthermore, the use of pozzolan in addition of chemical additives in the recent years help researchers to design specific concrete for specifics situations. In this research we evaluate the K factor in self-consolidating concrete. The k factor, expresses the effect of various pozzolans on strength and durability of concrete. Whereas in the same values the effect of silica fume is better than cement, fly ash and nature pozzolan have less effect in the same values. Thirty nine concrete mix designs with the water per cement ratios of 0.4, 0.45 and 0.50 and with the addition of silica fume, Khash natural pozzolan, zeolite and blast furnace slag were compared with normal concrete and then the K factor in self-consolidating concretes were calculated.