| Abstrakt: |
Structural characteristics of concrete incorporating Colloidal Nanosilica (CNS), Metakaolin (MK) and Alccofine (AF) were comparatively studied using X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Field Emission Scanning Electron Microscope (FESEM), and Fourier Transform Infrared spectroscopy (FTIR). The plasticizer demand and compressive strength at 3,7,28 and 90 days of curing ages were also determined. The results indicated that the demand for plasticizer content increased with CNS and MK incorporation owing to their large surface area and rough surface texture, respectively. However, AF decreased the plasticizer demand due to glassy surface morphology. Also, the compressive strength increased with replacement ratio. The tetranary blended systems (M6) proved to be more advantageous compared to binary, ternary and normal OPC systems. FTIR, TGA, XRD and FESEM analysis were consistent with the results of compressive strength. The improvement in properties of concrete at early ages was attributed to filler and nucleation effect of CNS and AF. At later ages, CNS modified the CSH by increasing the length of silicate chains, AF and MK diminished the portlandite content by utilizing it in pozzolanic reaction and filling of pores partially or completely especially by secondary CSH gel, led to denser structure. [ABSTRACT FROM AUTHOR] |
