A Case Study of Cement Performance in Different Concretes

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, ۱۰samples of Portland cement type II were prepared from ۹ cement factories and their physical, chemical and mechanical characteristics were determined. Then, ۵۰ different concrete mix designs were divided into five groups (۱-Unworkable, ۲-Workable, ۳-Medium Workable, ۴-High Workable and ۵-High Workable with admixture) and ۴۰۰ specimens at different ages were determined for compressive strength. In group۱ (NC), cement samples ۳, ۱, ۴, and ۷ with values of ۴۱.۲, ۳۸.۱, ۳۷.۸, and ۳۶.۴MPa, respectively, obtained the highest ۲۸-days compressive strength in concrete. In group۲ (HPC), cement samples ۷, ۱ with ۵۰.۸ and ۵۰.۲MPa showed the highest ۲۸-days compressive strength. This comparison in group۳ (RCC) for cement samples ۹, ۱۰ with ۲۸-days concrete compressive strength of ۱.۳۹MPa had the highest values. In group۴ (NC, w/c:۰.۶۵) cement sample ۸ with a ۲۸-days concrete strength of ۳۶.۵MPa and in group۵ (NC, w/c:۰.۷۶) cement samples ۲, ۶ with a ۲۸-days concrete strength of ۵ respectively ۲۵.۰ and ۲۴.۵MPa showed the highest results in their group.

کلیدواژه ها:

Slump ، fineness ، cement ، Compressive strength ، ratio W/C