CMP Repair and Rehabilitation Solution

Corrugated Metal Pipe Repair (CMP Repair) Solutions

CMP Repair has come up with the solution to corrugated metal pipe rehabilitation. The patent process will insure that the process is done reliably and cost-effectively. Our goal is to assist engineers in reducing cost and minimize future maintenance cost. CMP Repair is continually building relationships with Cities, Railroad Companies and Engineering Groups to repair culverts. CMP Repair works all over the Continental USA.

The Problem

The deterioration of CMP happens over time from the exposure of oxygen and moisture which forms rust. Deterioration depends primarily on soil conditions and the acidity of the water flow. In some instances, this condition can cause sinkholes to form that allow water to escape during a heavy rain and destroy property. Flow line corrosion causes loss of structural integrity. Bottom bedding and support fill is exposed and begins to erode away. As bottom bedding material is lost, flow begins to occur around and beneath the pipe. Side wall bedding and support material is lost leaving voids and loss of structural support. Sink holes start to develop at the surface. In such cases, it would be expensive and time-consuming to repair the entire pipe.

CMP repair and rehabilitation

CMP repair and rehabilitation after

The Application Process

Prior to beginning the work, all debris, stones, rubble and loose material will be removed from the pipe. Beginning at the outfall, the overlay sheets will be placed in the bottom of the pipe, centered over the corroded flow path, and pressed into place to conform to the arc of the pipe. While held in position, the metal sheeting will be fastened to each ridge of corrugation with a corrosion free fastener. Advancing in the counter‐flow direction, each subsequent section/sheet is “shingled” over the leading edge of the prior sheet with an overlap of 6”.

Once the needed sheets are installed, multiple injection holes (5/8” dia.) are drilled through the new invert and through the host CMP. The overlay sections/sheets will be blocked and braced sufficiently to prevent movement when the next step of injections begin. High Density Polyurethane (HDP) is injected in multiple locations through the injection holes, allowed to expand, void fill and seal the back side of the repair area. As necessary, polymer is injected at depth through injection tubes placed into the supporting subsoil so as to further strengthen and stabilize the supporting subsoil. Outcropped HDP material is removed with hand tools and disposed of. The repaired area is inspected for completeness.