Flowable high strength cementitious matrices for ferrocement applications

Laboratory investigation was undertaken to develop high strength cementitious matrices for casting thin ferrocement laminates ideally suited for structural repair/retrofit. The developed high strength mortar matrices contain various combinations of silica fume and fly ash, and provide a good balance between flowability and strength. The matrices developed had a 28-day compressive strength range from 48 to 64 MPa with a corresponding flow range from 129% to 138%. The developed high strength mortar was used in producing ferrocement jackets for cylindrical stubs to examine its performance and efficiency when the stubs are subjected to axial loads. The developed high strength ferrocement laminates seem to provide appreciable increase in load carrying capacity, lateral confinement and ductility. In terms of ferrocement efficiency, the stubs wrapped with the laminates containing 2 and 4 layers of welded wire meshes, WWM, showed about 16% and 29% increase in axial stress respectively, with a corresponding increase in axial strain of about 32% and 70% respectively. Based on the findings of the present investigation, high strength ferrocement laminates containing a specific number of welded wire meshes can be considered as a promising material for maintenance and rehabilitation of concrete structures, especially when using high strength and flowable mortar with WWM complying with ferrocement specifications.