Effect steel fibre content on the load‐carrying capacity of fibre‐reinforced concrete expansion anchor

Abstract

The article presents the pull‐out strength tests carried out on M10 expansion anchors in non‐cracked and cracked concrete with a crack width cw = 0.30 mm. The breaking loads and the average pull‐out strength of anchors in fibre‐reinforced concrete substrates were determined. Fibre content ratios of 15, 30 and 50 kg/m3 were used. In addition, two different classes of concrete (C20/25 and C50/60) were tested. The addition of steel fibres caused a decrease in the pull‐out strength by 5% for non‐cracked concrete of C20/25 class and fibre content up to 30 kg/m3 and a further 7% for the remaining specified dosage. While for concrete of the C50/60 class, it a decrease in the pull‐out strength of up to 20% was observed. For cracked concrete class C20/25 with crack initiation cw = 0.30 mm, the reduction was from 9% to 16% in relation to non‐cracked concrete and a maximum of 18% for the fibre content of 50 kg/m3. The difference between the tensile load capacity of C50/60 class cracked and non‐cracked concrete was lower than 5% and fell within the measurement error.