Study of Microstructure of Waste Tyre Ash (WTA) Concrete Using the Scanning Electron Microscopy (SEM) and X – ray Diffraction (XRD) Techniques

Abstract

This paper reports the findings of an investigation into the microstructure of WTA – Concrete. The WTA was obtained by open burning of waste tyre slices to a temperature of about 5000C for about five (5) hours at the local open burning sites in Kano. And after allowing to cool, it was sieved through 75 µm BS Sieve and characterized. The ash was subjected to chemical composition analysis using the X-Ray fluorescence (XRF) analytical method using the X –Ray spectrometer machine. The investigation was carried out on a concrete of 29 N/mm2 compressive strength, Water – cement ratio (w/c) of 0.65 and slump range of 10 – 50mm. The microstructure assessment was conducted on the concrete at WTA replacement levels of 0, 5, 10, 15, 20, 25, and 30% of cement weight, respectively to determine the influence of WTA on the microstructure of WTA – Concrete using SEM and XRD techniques. Both SEM analysis and XRD results of WTA – concrete indicated the occurrence of pozzolanic reaction between WTA and cement and that the WTA has more porous micro-structure than OPC concrete especially at hig