Loop connection with fibre-reinforced precast concrete components in tension

• We evaluate the influence of steel fibres on tension joints using overlapping loops.
• This connection is useful to reduce the joint width between precast elements.
• The overlap length of reinforcement loops is reduced by steel fibres.
• The steel fibres simplify the connection due to reduction of the reinforcement ratio.
• Comparison of tests and the proposed model shows satisfactory agreements.

Overlapping of reinforcement bars or loops is often used to connect precast members. The precast units have projecting bars, usually with a full 180° hook, which are embedded in situ in concrete after erection. This paper studies a tension joint using direct overlapping loops, evaluating the influence of the addition of steel fibres to the in situ concrete. Other variables studied were the diameter of the loop bend and the presence of transverse reinforcement in the loop. The results indicate the possibility of reducing the joint width between precast elements by using steel fibres. An expression based on strut and tie theory is proposed to calculate the connection’s strength, and it provided a good approximation to the experimental results.