Additionally, unregulated piles can attract rodents and biting insects which can carry diseases to humans such as encephalitis and murine typhus. Dr. Bruce Kjartanson at Iowa State University, Department of Civil and Construction Engineering, has been working with an Iowa company to perfect the use of tires in culvert construction. Researchers have worked to characterize the engineering properties of the tires, to evaluate the performance of the tires under actual field conditions and to develop . Currently, researchers have determined the significant parameters that affect a culvert tire's load bearing capabilities such as overall condition, remaining tread, and stiffness of the tire relative to size. In addition, various trench bedding conditions have been and are being evaluated using buried tires and buried analytical sensors known as displacement transducers, which record the performance of the tires given various backfill materials and compaction ratios.
Backfill materials evaluate thus far include glacial till and loess, two soil types common to Iowa.
Laboratory findings to date indicate that significant deformation of the tires does not occur when appropriate construction techniques and pre-selection of waste tires occurs. This will help eliminate concerns about culvert collapse and consequent water flow problems through the culverts. Work is on- going to evaluate culvert performance under real world conditions. Dr. Kjartanson's work will help to produce a well-researched set of guidelines for the use of waste truck tires as culvert construction materials.