Strengthening of rammed earth structures with simple interventions

This paper reports an experimental campaign to assess effectiveness of strengthening interventions on the out-of-plane performance of rammed earth (RE) structures in Bhutan. An innovative strengthening technique is proposed for strength enhancement of RE walls. The tests involved two types of specimens, an unreinforced RE structure and an identical reinforced counterpart. The strengthening strategy involved reinforced concrete sections of dowels and wedges inserted between the RE blocks at regular intervals. A floor anchorage system where wooden floor beams at the floor level are anchored to the RE blocks is also proposed. A maximum increment in peak pull-down load of 59% was observed for the reinforced RE specimen compared to its unreinforced counterpart. The unreinforced RE wall showed damage to a larger area of its facade, whereas the reinforced RE specimen only exhibited cracks in a relatively smaller zone, with a controlled failure mechanism. Detailed finite element models have also been developed to simulate and support the test observations.