| 3D non-linear elasto-plastic finite element models have been developed for hollow concrete masonry to simulate their structural behaviour when subjected to concentric and eccentric compressive concentrated loads. For every kind of hollow masonry for which experimental results are available (such as hollow masonry prisms, plain hollow masonry walls, walls with bond beams, and walls with grouted details), models were developed and verified first. The models were then used to predict situations where the masonry geometry and loading locations are not described in the literature. The failure mechanism of hollow masonry without vertical columns of grout under in-plane concentrated loading is by progressive web splitting of the hollow block units in the region beneath the loading plate, followed by spalling of the face-shells and/or mortar crushing. When the eccentricity of the load increases, the ultimate capacity decreases. When a concentrated load is applied over a grouted core in partially grouted hollow masonry, the failure mechanism is through splitting/spalling of the face-shells of the hollow block units attached to the columns of grout, followed by column crushing. An experimental study was performed to assess the critical predictions from the finite element models. The good agreements confirmed that the non-linear behaviour of the hollow masonry could be modelled successfully. Based on the available numerical and experimental studies, design rules for hollow masonry subjected to in-plane concentrated loads were proposed. Two possible failure zones were considered. Four important factors influencing the bearing strength were taken into account. When compared to the available numerical and experimental results, safe estimates of ultimate strength were obtained in all cases. |
