Document Type : Original Article
Chief of research and development of Tehran cement Co, Tehran, Iran
MA in English Translation of Tehran University
Cement manufacturers control the standard characteristics of products, but concrete manufacturers select cement with different criteria such as workability and compressive strength of concrete. Therefore, some issues such as reaction with additives, achieve strength process, performance in different applications are less considered. There are few refers and studies in the field of how to check and perform cement in all types of concrete; So, in this study, an attempt has been made to take a comprehensive and detailed look at this subject with multiple criteria. In this extensive research, 10samples of Portland cement type II were prepared from 9 cement factories and their physical, chemical and mechanical characteristics were determined. Then, 50 different concrete mix designs were divided into five groups (1-Unworkable, 2-Workable, 3-Medium Workable, 4-High Workable and 5-High Workable with admixture) and 400 specimens at different ages were determined for compressive strength. In group1 (NC), cement samples 3, 1, 4, and 7 with values of 41.2, 38.1, 37.8, and 36.4MPa, respectively, obtained the highest 28-days compressive strength in concrete. In group2 (HPC), cement samples 7, 1 with 50.8 and 50.2MPa showed the highest 28-days compressive strength. This comparison in group3 (RCC) for cement samples 9, 10 with 28-days concrete compressive strength of 1.39MPa had the highest values. In group4 (NC, w/c:0.65) cement sample 8 with a 28-days concrete strength of 36.5MPa and in group5 (NC, w/c:0.76) cement samples 2, 6 with a 28-days concrete strength of 5 respectively 25.0 and 24.5MPa showed the highest results in their group.