Assessment of mechanical properties in Portland cement by optical microscopy and numerical color analysis

Abstract

Cement industry has an production output of clinker which directly affects the quality of cement. Different raw materials preferred and furnace conditions followed have an essential impact on clinker and cement characteristics. Therefore, determination of phase occurrences, sintering behavior and porosity aspects are sensitively followed so as to achieve high quality clinker as well as cement. However, controlling and confirmation of final product parameters take very long times. In this study, it is aimed to assess the mechanical properties of ordinary Portland cement (OPC) by performing optical microscopy measurement and numerical color analysis. For that purpose, two types of cement samples (CEM I 42,5R and CEM I 52,5N) were taken from a company in Afyonkarahisar/Turkey. Uniaxially pressing was performed to moisturised cement samples in order to have flat surface, and then pressed samples were sticked to lamelleas and made thin sections to get visible and smooth surface for optical microscopy measurement. The images taken from optical microscopy were analyzed via MATLAB software to obtain color distributions in terms of RGB (red-green-blue) values. It was observed that consistent results regarding cement type was determined and these consequences were also verified with production datas, particularly mechanical properties. It was found that as blue color value increase the mechanical properties of cement is improved.