Strength properties of high-volume fly ash (HVFA) concrete incorporating steel fibres: Fid-Bau Portal

Strength properties of high-volume fly ash (HVFA) concrete incorporating steel fibres

Siddique, R. / Khatib, J.M. / Yüksel, I. / Aggarwal, R.

Properties of HVFA (high-volume fly ash) concrete incorporating steel fibres are presented in this paper. Three concrete mixtures were prepared with 35%, 45%, and 55% of Class F fly ash as partial replacement of cement. Straight-round steel fibres of aspect ratio 80 (0.75% by volume of concrete) were added in each of the fly ash concrete mixtures. Tests were performed for fresh concrete properties, compressive strength, splitting tensile strength, flexural strength, and impact strength at the ages of 28 days, 91 days and 365 days. 28 days test results indicated that steel fibres increased compressive strength of high-volume fly ash concrete by 12% to 19%, splitting tensile strength by 37% to 45%, flexural strength by 15% to 21%, and enhanced impact strength tremendously (4 times to 6 times) depending upon the fly ash content. At later age (91 days and 365 days) continuous increase in strength properties of high-volume fly ash concrete was observed. Paper also presents the correlation between impact strength with compressive strength, splitting tensile strength, and flexural strength. It has been found that impact strength of high-volume fly ash concrete has very good correlation with compressive strength (R2 between 0.9816 and 0.99), splitting tensile strength (R2 between 0.9432 and 0.9838) and flexural strength (R2 between 0.9846 and 0.9970) depending upon the fly ash content and testing age.