9634685 Vipulanandan One of the biggest problems faced by the U.S. today is the rehabilitation/replacement of millions of miles of decaying underground wastewater pipelines. The conventional method of open trench construction is not only disruptive to urban life but also costly. The disruption and cost can be reduced by using trenchless technology methods that are becoming popular in recent years in the U.S. One of the most popular trenchless techniques is microtunneling, a laser guided, pipe jacking process. For microtunneling, the pipes must have higher compressive stiffness and strength to avoid failure during jacking and higher pipe stiffness and strength compared to plastic pipes to maintain alignment during jacking. In order to satisfy the installation and service loading conditions and to resist crown corrosion, an ideal candidate for underground wastewater pipelines must satisfy the following three criteria: (1) High compressive stiffness and strength (axial), (2) High pipe stiffness and strength (lateral), and (3) Good corrosion resistance. It is planned to develop new sandwich pipes that satisfy these three criteria. In order to demonstrate the concept of sandwich pipe, high corrosion resistant polyvinyl chloride (PVC) pipes are selected as the outer and inner tubes to encase the filler materials with good mechanical and/or bonding properties. Variety of filler materials including polymer concrete and cement concrete will be investigated. ***
