Saeed Pourfallah - Research student, Department of Civil Engineering, Shiraz University
M. R. Maheri - Professor, Department of Civil Engineering, Shiraz University,
M. A. Najafgholipour - Research student, Department of Civil Engineering, Shiraz University

Considering the widespread use of jack arch roofs and the need for seismic retrofitting of this system of flooring in Iran the behaviour of the retrofitted form of these slabs is unknown. The Iranian building codes also do not deal sufficiently with this type of roofing and as a result little control is applied on their method of construction. The retrofitting method of adding a concrete layer (CL) is a method which was first introduced in Romania after the earthquake of 1990. This paper reports on an experimental investigation of this method and comparison with other retrofitting methods. For this purpose, a number of slabs with different methods of retrofitting such as the Romanian method, the method recommended by the Iranian Standard 2800, the two way method and a slab without retrofitting were constructed. Then, the slabs were loaded step by step in out of plane direction and the load-displacement pushover curves for the slabs were obtained. Using these curves, the seismic strength parameters of different slabs are determined and compared.

jack arch slabs, retrofitting, concrete layer, masonry, pushover test