A method for reinforcing a structure comprising the following steps: preparation of UHPFRC comprising a cement precursor mix, of water, a fluidizing agent and metal fibers, transporting the UHPFRC by pumping to a suitable spray nozzle, spraying the mix onto a surface of the structure by the addition of a compressed air stream in the spray nozzle.

A nozzle includes a main chamber defining a first internal space, a first inlet defined in a first end of the main chamber to couple to a material sprayer, a second inlet to receive a solid material into the main chamber, and an outlet defined in a second end of the main chamber. The first inlet upstream from the second inlet to allow a fluid material to enter the main chamber before the solid material. The main chamber configured to mix the solid material with the fluid material.

A method of agglomerating bulk ceramic fibers includes mixing the bulk ceramic fibers with water to form wet fibers; mixing the wet fibers with a binder including an organic binder and/or an inorganic binder to form agglomerates; and drying the agglomerates. The agglomerates may be mixed with additional binders and fillers to form an insulating mix that may be used to insulate a furnace or other heat source. A foaming nozzle may be used for the application of agglomerates. A foaming agent and water are air atomized within the foaming nozzle and the resulting foam is mixed into pneumatically conveyed agglomerates, which result results in a lightweight refractory material layer on a target substrate.

A method for reinforcing a structure comprising the following steps: preparation of UHPFRC comprising a cement precursor mix, of water, a fluidizing agent and metal fibers, transporting the UHPFRC by pumping to a suitable spray nozzle, spraying the mix onto a surface of the structure by the addition of a compressed air stream in the spray nozzle.