Experimental campaign of thin reinforced concrete shear walls for low-rise constructions

Abstract

The Chilean reinforced concrete (RC) code (decree DS 60) allows the use of ordinary RC walls for structures up to five stories if the structure is designed with a strength reduction factor equivalent to that of masonry. This clause allows the use of thin walls up 100 mm thickness, and the use of single layer reinforcement. The local industry is pushing for this type of structures, even though, the seismic performance of these walls have not been proved locally in the last earthquakes. This paper summarizes an experimental campaign conducted to characterize the seismic behavior of thin RC walls with single layer reinforcement for housing applications. The proposed tests are intended contribute to the understanding of the seismic behavior of thin RC walls with single-layer reinforcement by providing additional tests results. The test program consistedon nine full scale specimens subjected to lateral cyclic displacements and no axial loads. The length and height of the walls were 1600 mm, and the aspect ratio 1.0. The thickness of the reference wall (WSL1) was 100 mm, and it was designed with a single layer of reinforcement. A welded-wire mesh with a vertical and horizontal reinforcement ratios of 0.002 was used for the reference wall. The variables analyzed in the test program are the type of steel (welded-wire mesh or deformed bars), the reinforcement ratio, and the wall thickness. Preliminary results are summarized on this paper. Results from these tests may be used to validate the seismic behavior of thin RC walls with single layer reinforcement and for seismic risk assessment of low-rise residential structures and houses with RC walls. Additionally, it is concluded that the ACI 318 equations predicted the strength of the tested walls more accurately than the equations proposed by Carrillo and Alcocer.