Performance of masonry buildings and churches in the 22 february 2011 christchurch earthquake

As part of the „Project Masonry‟ Recovery Project funded by the New Zealand Natural Hazards Research Platform, commencing in March 2011, an international team of researchers was deployed to document and interpret the observed earthquake damage to masonry buildings and to churches as a result of the 22nd February 2011 Christchurch earthquake. The study focused on investigating commonly encountered failure patterns and collapse mechanisms. A brief summary of activities undertaken is presented, detailing the observations that were made on the performance of and the deficiencies that contributed to the damage to approximately 650 inspected unreinforced clay brick masonry (URM) buildings, to 90 unreinforced stone masonry buildings, to 342 reinforced concrete masonry (RCM) buildings, to 112 churches in the Canterbury region, and to just under 1100 residential dwellings having external masonry veneer cladding. In addition, details are provided of retrofit techniques that were implemented within relevant Christchurch URM buildings prior to the 22nd February earthquake and brief suggestions are provided regarding appropriate seismic retrofit and remediation techniques for stone masonry buildings.The authors acknowledge the financial support for Project Masonry from the New Zealand Natural Hazards Research Platform. The testing of adhesive anchors was undertaken in conjunction with the RAPID grant CMMI-1138614 from the US National Science Foundation. The investigation of the performance of residential brick veneers was financially supported by Brickworks Building Products Australia

Behavior and design of CFRP post-tensioned masonry diaphragm walls

Bibliography: p. 146-160

The Effect of the Amount, Distribution and End Anchorage Conditions of Bond Beam Reinforcement on the Behaviour of Concrete Masonry Shear Walls

The behaviour of square shape partially grouted concrete masonry shear walls with fixed end boundary conditions subjected to constant average axial stress and cyclic lateral loading was investigated. Two replicas were tested of each combination of horizontal reinforcement ratio (0.12%, 0.06% and 0.03%) and four end anchorage conditions (straight, 90, 180 and shear studs). The behaviour of the walls was compared in terms of strength, ductility, stiffness and dissipated energy. While the effect of horizontal bar size was greater than that of end anchorage, neither improved end anchorage nor the smaller bar size increased yielding at critical locations on the rebars. The highest course of the wall should be reinforced and grouted as it improves performance of the walls. In addition, the amount of horizontal reinforcement did not significantly affect the strength of the shear walls, therefore changes to the shear design equations in the Canadian Standard are recommended.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Shear in plain, bed joint reinforced, and post-tensioned masonry

Masonry is cost competitive on a life cycle basis with other forms of construction, and should therefore be considered as a structural material more frequently by both architects and engineers. Post-tensioned geometric sections of masonry are structurally efficient wall systems. Post-tensioning with carbon fibre reinforced polymer (CFRP) is an attractive solution to potential corrosion problems with unbonded tendons. Tests on CFRP post-tensioned diaphragm walls have revealed that shear strength in prestressed masonry is an area deserving more study and improvement. The tests also showed that the bonding pattern of the masonry at the web-flange junction can have a substantial effect on the resulting strength of that connection. A test series to evaluate the effects of prestress force and bed reinforcement on shear strength has been carried out and a summary of the results is presented here. Tests to determine the effect of bonding pattern on the strength of the web-flange connection have also been conducted