Seismic retrofitting of rural rammed earth buildings using externally bonded fibers

• A retrofitting technique for existing rammed earth walls is proposed.
• The most suitable retrofitting materials and adhesives are selected by bonding tests.
• The technique can greatly increase the seismic behavior of the rammed earth wall.
• The proposed technique is simple and economical for implementation.

The 2014 Mw 6.5 Ludian earthquake, in rural Yunnan Province, China, claimed 615 lives. This disaster reminds us of the importance of developing practical, inexpensive and effective retrofitting techniques to strengthen the seismic capacity of rammed earth residential dwellings in underdeveloped rural regions. This study proposes a retrofitting technique for such buildings involving externally bonded fibers. The most suitable and practical retrofitting material and adhesive were chosen based on a series of tests of candidate materials and combinations. The rammed earth wall specimens were strengthened with the proposed retrofitting technique and loaded to failure condition under in-plane shear loading. It was observed that the lateral-load capacity and ductility of the reinforced walls were greatly increased using the proposed technique.