By combining the advantages of conventional reinforced concrete construction with unbonded post-tensioning, a hybrid is created that provides the opportunity to significantly and cost-effectively improve the seismic performance of structural wall systems. The implementation of this hybrid wall system is illustrated using a recently completed seismic retrofit of an existing six-story non-ductile concrete building in Berkeley, CA. Various restrictions during the retrofit led to the use of shotcrete to construct the walls, micropile foundations, and carbon fiber collector elements.

By combining the advantages of conventional reinforced concrete construction with unbonded post-tensioning, a hybrid is created that provides the opportunity to significantly and cost-effectively improve the seismic performance of structural wall systems. The implementation of this hybrid wall system is illustrated using a recently completed seismic retrofit of an existing six-story non-ductile concrete building in Berkeley, CA. Various restrictions during the retrofit led to the use of shotcrete to construct the walls, micropile foundations, and carbon fiber collector elements.