Cyclic Testing of Rammed-Earth Walls Containing Post-tensioned Reinforcement

Rammed-earth walls are generally constructed by hand-compacting (or mechanically) a moist, soil-cement mixture into forms. These walls, when constructed in seismically active areas, require the use of steel reinforcement. The installation of steel reinforcement during rammed-earth construction can be difficult logistically. In particular, vertical reinforcing bars are difficult to place and to reach proper compaction of the surrounding rammed earth. To evaluate the use of post-tensioned reinforcement in lieu of bonded mild steel, eight full-scale rammed-earth walls were constructed and tested in out-of-plane and in-plane bending. The loads were cyclic and fully reversed to determine the ability of the walls to undergo large displacements that might accompany an earthquake. The out-of-plane tests were conducted with the specimen supported as a cantilever and the lateral load applied to the top of the wall. The specimens in the in-plane tests were also supported as a cantilever with the top unrestrained.