Tests of full-size composite beams with perfobond rib connectors

Abstract

This paper presents the test results of six full-size composite beam specimens with perfobond rib shear connectors embedded in solid concrete slab. The objective of this investigation was to study the performance of this connector in full-size composite beams and to correlate the test results with those obtained from push-out specimens. In the first three beam specimens, the amount of transverse reinforcement was varied. Two other specimens were used to investigate the effectiveness of more perfobond rib connectors of shorter length. The effect of passing transverse reinforcing bars through the connector rib holes was investigated using the last specimen. Failure of the test specimens was initiated by longitudinal splitting of the concrete slab, eventually culminating in the crushing of concrete in the bearing zone immediately in front of the end perfobond rib connectors. The test results showed that increasing the transverse reinforcement ratio, excluding the wire mesh, from 0.11% to 0.20% led to a 10% increase in the ultimate capacity. The test specimen with six 251 mm long connectors sustained 11% higher ultimate capacity compared to that with four 376 mm long connectors. An increase of 8.4% in the ultimate strength was observed when transverse reinforcing bars were passed through the perfobond rib holes while keeping the total amount of transverse reinforcement unchanged. The experimental values of the ultimate flexural capacity of the beam specimens were, on the average, approximately 1.11 times the predicted values based on push-out test results. Key words: composite beam, perfobond rib connector, push-out test, full-size test, flexural capacity.