This paper describes the influence of the producing method (inter-grinding and separate grinding) and particle size distribution (PSD) on long term properties of blended cements. Portland cement (PC), limestone and a natural pozzolan (Trass) were used in binary and ternary cementitious blends. In this study, 14 types of cements including two types of Portland cement (PC), four types of Portland-limestone cement (PLC), four types of Portland-pozzolan cement (PPC), and four types of Portland-composite cement (PCC) were used. The results show that for achieving the same percentage of 45-lm residue in blended cements containing Trass, inter-grinding was less energy-demanding than separate grinding (shorter grinding time was required). Also, PPC and PCC provided better durability properties compared to PC and PLC properties. In addition, particle size distribution (PSD) and long term properties of blended cements with same percentage of 45-lm residue were not affected significantly by grinding method. Furthermore, the use of cements with high fineness seems not economically beneficial due to its low effect on long term properties.
