investigating efficiency of shotcrete for retrofitting masonry buildings

One of a feasible and efficient method to retrofit structures is spraying shotcrete which is widely applied around the world. shotcrete is concrete with fine aggregates which are sprayed through a hose and by air pressure coat at high velocity onto a surface. in the current research, three masonry schools from different regions of iran are selected. the retrofitted wall surfaces have been prepared and became flatted, and schmidt hammer and ultrasonic tests are performed for each point. the results from the experimental investigation are compared with each other, and some experimental results are compared with theoretical results. to investigate the seismic behavior of structures, one of the schools is chosen and then finite element method is used to do time history analysis regarding four ground motions record. finally, there was an agreement between experimental and theoretically dynamic modules. in retrofitted conditions, the obtained frequencies are more than the unretrofitted condition and dynamic time history analyses have shown that in retrofitted condition, the displacements will decrease and the seismic performance of structure will increase considerably.