Seismic behavior of autoclaved aerated concrete masonry walls reinforced with glass-fiber geogrid

Abstract

Reinforcing horizontal mortar joints with steel bars can improve the seismic performance of autoclaved aerated concrete (AAC) masonry walls. Nevertheless, the diameter of steel bars can require a large thickness of the mortar joints, which in turn results in the thermal bridging effect. Glass fiber geogrids (GFGs) can be employed to replace steel bars to reduce the thickness of mortar joints, and thus can mitigate the thermal bridging effect. Despite considerable advancements in understanding the mechanical performance of GFGs in masonry walls, their effect on the seismic performance of AAC walls remains unknown. Therefore, this study investigates the effect of different GFG configuration rates on the seismic performance of AAC masonry walls using reciprocating load tests. Furthermore, the effect of different vertical compressive stresses on the seismic performance of GFG-reinforced AAC masonry walls was studied via comprehensive finite element simulations. The test results show that the ultimate load-bearing capacity and ultimate displacements of the wall specimens were enhanced as the GFG configuration rate increased, approaching that of benchmark specimens reinforced with steel bars. On the other hand, the cracking and ultimate loads, along with ultimate displacements of GFG-reinforced AAC masonry walls were significantly improved compared to those of the unreinforced AAC masonry walls. It was also evidenced that the crack formation, failure mode, ductility and energy dissipation capacity of the specimens simulated through the finite element method were highly comparable to that of experimentally tested specimens. Accordingly, the vertical compressive stresses were in the range of 0.1 MPa ∼ 0.6 MPa, while the seismic performance of GFG masonry walls was improved with the increase in vertical pressure. The results of the current study confirm that embedding GFG in horizontal mortar joints can delay the cracking of AAC masonry walls and improve their seismic performance. Ultimately, an empirical equation was developed to calculate the seismic shear strength of GFG-reinforced AAC masonry walls.