Design codes prescribe equations for ultimate state design of RC walls with flange walls as boundary elements considering part of the length of the flange wall as an effective width to resist lateral loads. However, the damage state and the accuracy of the effective width used in calculation have not been discussed. Therefore, loading test was carried out in Yokohama National University on two 1/3 scale specimens in order to evaluate the strength, damage state, energy dissipation and behavior of RC structural walls in flexure. One specimen without flange walls and one with flange walls were tested.
The strength and response of each specimen were described, and the prediction accuracy of the design flexural strength given by design codes ACI, Eurocode and AIJ was examined.
Experimental strain data was used to describe the behavior of the flange wall, in order to know the mechanism it develops when the in plane wall is loaded, and to confirm the accuracy of the effective width prescribed by design codes in tension and compression.
The result of the experimental study revealed that design prescriptions given by ACI, Eurocode and AIJ guidelines can estimate conservatively the flexural strength for RC walls without flanges, but they underestimate the flexural strength for flanged walls. This underestimation is due to the lack of knowledge of the mechanism developed at the flange.
It was not possible to determine a specific value of flexural effective width. However, it was confirmed that the flange width is underestimated by design codes and it increases with imposed drift level. The stress distribution at the flange in the out of plane direction was found not uniform, a fact that is different as the design assumptions.