PROPERTIES OF CONCRETE INCORPORATING HIGH VOLUMES OF CLASS-F FLY ASH AND STEEL FIBRES

The results of an experimental investigation to study the effects of replacement of cement (by mass) with three percentages of high fly ash content, and the effect of addition of steel fibres on the slump, Vebe time, compressive strength, split tensile strength, flexural strength and impact strength of high fly ash concrete are presented. A control mix of proportions 1:1.4:2.6 with water cement ratio 0.46 and superplasticizer-cementitious ratio of 0.015 was designed. Cement has been replaced by mass with 35, 45, and 55% of fly ash content. Three percentages of steel fibres (0.30, 0.60 and 0.90%) of aspect ratio 80 have been used in the investigation. The test results indicate that replacement of cement with fly ash increases the workability (slump and Vebe time), decreases compressive strength, split tensile strength, flexural strength, and have no significant effect on the impact strength of plain concrete. Addition of steel fibres reduces the workability, does not significantly affect the compressive strength, and increases the split tensile strength and flexural strength, and tremendously enhances the impact strength of high fly ash concrete with an increase in percentages of fibres.

• ABSTRACT

• INTRODUCTION

• EXPERIMENTAL PROGRAMME

• RESULTS AND DISCUSSION

• CONCLUSIONS

• REFERENCES