Comparative study of different infill materials in confined masonry using analytical model

Confined Masonry (CM) is attracting increased attention as a seismic resistant structural solution in regions of high seismicity on account of its greater agility to withstand destructive earthquakes. The choice of infill material presents a conflicting scenario between strength and density as the heavier material usually stronger also attracts more earthquake force on account of its larger mass. This study presents the comparison of four contemporary materials viz. AAC blocks, LWC panels, fly ash bricks, and clay bricks concerning their suitability as infill materials in CM. The study is carried out based on analytical model programmed in MATLAB for the combined effect of earthquake force as a lateral load and self-weight as the gravity load. The initial model developed for a single bay CM frame treating the section as composite and assuming the response of the system to follow the beam bending theories is later to be modified to include multiple bays and more realistic response of CM. The allowable compressive and tensile stress of the infill material is used to determine maximum earthquake force that can be withstood by the CM wall. Based on the response, the best infill material that will attract least earthquake force and displace the least is determined. Based on the modelling outcomes the AAC blocks resulted into least stresses followed fly ash bricks, LWC panels and clay bricks.