Earth is suffering from global warming phenomena in which carbon dioxide plays a major role. Portland cement industry is one of the main sources of carbon dioxide emissions. The aim of this study is to minimize the production of carbon dioxide by reducing the Portland cement content -in production of cement based composites. Therefore, the influence of using different pozzolanic materials as partial replacement of the Portland cement was investigated. Fly ash and micro silica fume were added -as pozzolanic materials - to Portland cement with different replacement ratios to form different blended cement batches. In addition, performance of cementitious materials made of slag cement was also compared with that made of ordinary cement. The blended cement batches were used for making various mortar and concrete samples. The Main physical and mechanical properties of the concrete and mortar samples were investigated in addition to some durability characteristics.Generally, the test results show that using pozzolanic materials as partial replacement of Portland cement affects the properties of the tested cementations materials depending on the replacement percentage of each type of the pozzolanic materials. For each type of the used pozzolanic materials the optimum dosage -at which the maximum improvement had occurred-was determined for various samples properties. The mortar late compressive strength (i.e. 56 days) reached its maximum value by using 10% micro silica and 20% of fly ash replacement. On the other hand, different durability properties were remarkably improved by using the suggested pozzolanic materials. Water permeability of concrete samples had been reduced by 30% and 40% by replacing 10% of ordinary cement with micro silica fume and 20% of ordinary cement with fly ash respectively. On the other hand, significant reduction (average 75% reduction) of chloride ion penetrability of concrete samples had been monitored by replacing ordinary cement with the proposed ratios of micro silica and fly ash respectively. Both enhanced durability characteristics provide enough potential for the ongoing research work to study the corrosion protection of steel bars embedded in concrete made with the proposed blended cement as well as sulfate resistance provided by this blended cement.