Natural disaster mitigation using advanced ferrocement – Future research directions for improved building resilience

Natural disaster mitigation encompasses a wide range of activities which are required to avert the occurrence of natural disasters and is a major goal of the Sendai Framework applicable to all exposed territories worldwide. With respect to earthquakes and hurricanes, the structural retrofitting of buildings which were designed before the availability of seismic codes of practice, or the enforcement of existing codes, can be an effective form of mitigation. Advanced Ferrocement (AF), which is ferrocement based on Lamination Theory (LT), encompasses the use of mesh angle, layer-by-layer mesh layup, possibly with non-metallic mesh, and/or non-standard mortars, for the design and construction of structural components. As a pilot study, a set of core research questions and nine research directions or study areas are presented for investigating the use of AF for retrofitting existing buildings, in the context of earthquake and hurricane resilience. This is also useful for deriving new structural components for new buildings,. The experimental results of the pilot study are that when ferrocement overlays were applied to the faces of concrete masonry-infilled walls of steel frames, the lateral yield strength and displacement at yield increased by factors of 1.50 and 2.30, respectively. For the tested ferrocement shear panels of channel-shaped cross-section, the lateral maximum strength-to-weight ratio was 3.37 times higher than that for an alternative reinforced concrete masonry minimum cost solution. For the tested AF one-way spanning roof panel, the wind load capacity had a strength-to-weight ratio 10.78 times higher compared with the present minimum cost metal sheet-and-purlins solution. LT suggests that the performance of the infilled-frame retrofit, and the ferrocement wall panel, can be increased by aligning the mesh in the principal stress directions, etc. The research directions and preliminary findings presented can serve as the basis for an extensive research effort regarding AF as the application of LT to mesh-reinforced cementitious composite structural building components.