Performance of Concrete at Elevated Temperatures: Utilizing A Blended Ordinary Portland Cement (Opc)/ Saw Dust Ash (Sda) As Binder

Abstract

This study aimed at investigating the effect of subjecting concrete, produced with cement being partially replaced with saw dust ash (SDA) to elevated temperatures. The performance of the test concrete cubes was done by exposing them to elevated temperatures of 200oC, 400oC, 600oC and 800oC, and allowed to cool down to room temperature before testing for their properties. Both the physical and thermal properties of the concrete cubes were determined. The concrete produced by blending cement with 10% SDA with an average percentage loss of 23.04% retained more of its compressive strength when exposed to the different temperatures, than concrete produced using only OPC, which has an average percentage loss of 29.11%. It is also found that, at an elevated temperature of 800oC, concrete fail totally in flexure due to the effect of high heat on binding elements. The flexural strength of both the control concrete (at 0% OPC replacement) and OPC/SDA blended concrete (at 10% OPC replacement) decreased as the temperature is increased. The replacement of OPC by 10% SDA increased the thermal shock resistance of the concrete by 11 cycles than the 0% OPC concrete at the same temperature. The concrete produced with OPC has better thermal conductivity than the concrete produced by blending OPC with SDA, as a result, the dislodgement of the concrete edges is relatively lower in the SDA blended cement concrete than in the OPC concrete. The result shows that, blending OPC with SDA in concrete performed better at elevated temperatures than concrete produced with only OPC. Therefore, the replacement of OPC with 10% SDA can be applied as a fire resisting bonding material in concrete.