We are studying a repair to an existing large-diameter corrugated metal pipe. The owner requires that the repair meet the fifth edition of the AASHTO LRFD Bridge Design Specifications with 2010 Interim Revisions. We want the owner to consider shotcrete as opposed to installing a new carrier pipe. I have pipe dimensions, depth, and so on, but need some help deciding if this is practical.

Shotcrete has been used in many cases to repair, rehabilitate, and strengthen pipes, culverts, and tunnels. It is not uncommon to use shotcrete to strengthen a culvert under a highway or roadway section. Shotcrete is a method of placing concrete at a high velocity. The shotcrete placed inside the existing pipe can be designed for strengths from 4000 to 10,000 psi (27.5 to 69 MPa), depending on the amount you are willing to spend on the shotcrete products. We cannot speak to the acceptance by the governing body, but it has been done successfully and often in the past. It is vitally important that the shotcrete contractor be competent and experienced in installing the lining. Your specification should require evidence of similar previously completed projects with current references.