The determination of some physical and mechanical properties of cements with different fineness and containing mineral additives

In this study, pozzolanic featured grinded Bayburt Stone (BT) and Bottom ash of Yatağan Thermal Power Station (TK), with 63 and 125 µm fineness respectively are used to replace CEM-I type cement at 0%, 10%, 20%, and 30% by weight. The aim of this study is to investigate the effects of mineral additives with different fineness on physical and mechanical properties of composite cements. It is also investigated whether produced composite cements are compatible with chemical admixtures. In this context, same type plasticizers belonging to two different firm are tried on mortar and paste with produced compose cement, some of physical, mechanical and rheological effects are investigated. For this purpose, standard consistency, setting time and volume expansion tests are performed on the cement pastes according to TS EN 196-3. Also, flextural strength and compression strength tests are performed on the cement mortars according to TS EN 196-1, and flow table values are obtained for relevant samples according to ASTM C230. After mortar specimens for mechanical strengths are kept in curing pool 28 days, compressive and flexural strength tests are performed on the mortar specimens at the ages of 2, 7 and 28 days. As a result, changes in specific surface area depending on the particle size distribution of mineral additives makes significant different on the physical, mechanical and rheological properties of cement mortars. Additionally, homogeneous chemical additives belonging to different companies show similar but different effects on behaviors of cement mortar and paste. As long as replacement values of BT and TK increase in the cement paste, standard consistency and setting final time of cement pastes increase. The blended cements containing 10%-20% BT and 10%-20% TK has shown comparable results at the end of 28 days curing time. The compressive strength of blended cements increases for increasing values of surface area of the cement. Also, the replacement of Portland Cement by mineral additives has no remarkable effect on the expansion of cement paste. Key words: cement / mortar / paste / Bayburt Stone / bottom ash / chemical additives / fineness