Determination of metakaolin blended cement composites characterizations using spektroscopic methods

The aim of this study is to decrease the consumption of cement in cementitious composites and to determine characterizations of metakaolin blended composite binders which are especially used to improve the durability parameters of cementitious composites using spektroscopic methods. In this study, White Portland Cement CEM I 52,5 R (PC) used as binder for architectural applications to product especially high strength cementitious composites was used and also metakaolin (MTK) was used as pozzolan. Hybrid binders were obtained as adding MTK into PC at ratios of 5%, 10%, 15%, 20%, 25% and 30%. The physical, chemical, mineralogical and molecular properties of PC and MTK were determined. The standard cement experiments were performed on prepared cement pastes and mortars. The flexural and compressive strengths of cement mortars prepared with PC and MTK were measured on 2., 7., 28., 56. and 90. days. Using the techniques of the X-ray Diffraction Spectroscopy (XRD), Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR) analysis were made on cement pastes to determine the mineralogical structure and phase development during the hydration at the end 28. Day. Also the micro-structure of cementitious composites were investigated using the Electron Microscope (SEM). As a result, the strength values of 28 day are decreased with the increase of MTK substitution rate, but it is seen that the significant increase in strength on the 56th and 90th day values due to the pozzolanic effect is obtained. Spectroscopic methods such as DTA, TGA, FT-IR, XRD and SEM can be used as reliable identification methods to determine the structural changes due to the pozzolanic effect during hydration of MTK substituted in PC.