The influence of lateral pressure upon anchorage bond

Synopsis This paper examines the effect of lateral pressure upon the anchorage bond behaviour of both plain and deformed reinforcing bars in lightweight-aggregate concrete. Two common bond tests, the cube pull-out and the semi-beam tests, were modified that lateral pressures could be applied to the bond specimens. The major variables studied were the magnitude of the lateral pressure, the bar diameter. the length of embedment and the concrete strength. The results of over 200 bond tests show that for plain bars the application of lateral pressure can result in an increase in pull-out load of over 250%, whilst for deformed bars of similar size the corresponding increase is about 75%. The different bond mechanisms for plain and deformed bars were highlighted by the failure modes of the bond specimens; this difference in behaviour is rejected in the theoretical work by a frictional bond strength criterion for plain bars and a splitting or shearing criterion f or deformed bars.