A cementitious composite includes a structure layer, a cementitious material, a water-impermeable sealing layer, and a containment layer. The structure layer has a first side and an opposing second side. The structure layer defines a plurality of open spaces. The cementitious material includes a plurality of cementitious particles disposed within the plurality of open spaces of the structure layer. The water-impermeable sealing layer is disposed along the first side of the structure layer. The containment layer is disposed along the opposing second side of the structure layer. The containment layer is positioned to prevent the plurality of cementitious particles from migrating out of the structure layer through the containment layer.