M. GILBERT*, B. HOBBS**, T.C.K. MOLYNEAUX***, C. MELBOURNE****, A.J. WATSON*
*The University of Sheffield, **The University of Teesside, ***The University of Liverpool, ****The University of Salford
A novel impact test rig, which uses a dropping weight and rotating quadrant arrangement to generate horizontal impact loads, is described together with a programme of tests on full scale masonry walls. The walls were representative of typical bridge parapets and incorporated a range of wall materials, lengths and thicknesses. The dynamic loading characteristics were designed to represent accidental vehicle impacts and were applied either at mid-length or close to the end of the wall. An extensive array of instrumentation was used for each wall test, including load cells, crack detectors, displacement transducers and video. The 21 wall tests performed to date indicated that the rig was performing correctly. It was found that long walls failed in mechanisms which involved the formation of either vertical or diagonal fracture lines, depending on unit type, and that shorter walls were prone to overturning. Following initial fracture, inertial forces and base friction provided resistance to overall wall movement. Wall thickness appeared to have little influence on the failure mode, but significantly affected the maximum resistance. It is concluded that the test technique provides a convenient and effective approach for the investigation of the response of masonry walls to impact loads.