In Ohio, engineers repaired a failed State Route 271 embankment with recycled foundry sand; ODOT said proper moisture control helped achieve adequate compaction

Road embankments must withstand traffic loads, changing weather, and the movement of water through the soil. When one fails, engineers must find a fill material that provides stability and meets construction requirements. One example comes from Ohio, along State Route 271. The Ohio Department of Transportation (ODOT) used recycled foundry sand to repair the failed embankment. ODOT engineers chose the sand because it was readily available and because they judged its strength and permeability suitable for the repair.Laboratory testing helped evaluate the foundry sandThe Federal Highway Administration (FHWA) documented the project in its January 2003 Report on Use of Recycled Foundry Sand in the Cleveland Area. The report describes how the sand was tested before ODOT used it to repair the State Route 271 embankment. An independent consultant, EPD Consultants, Inc., tested properties including grain size, moisture-density relationship, direct shear strength, electrical resistivity, and chemistry. The report calls the amount of testing the real merit of the project. The report lists a maximum dry density of 107 pounds per cubic foot at 14% moisture content. It also lists a direct shear result of 350 against a specification of more than 340, though it does not state the units. These values apply only to the material used on this project, since foundry sand varies with its origin and prior use.Moisture control helped achieve adequate compactionMoisture content affects how densely a material can be compacted, so moisture management matters during construction. The same report says ODOT personnel credited proper moisture content with producing adequate compaction and making the project a success. Water was added periodically to keep the sand at optimum moisture. ODOT Specification 871, which the report quotes, calls for placing foundry sand in horizontal loose lifts of no more than 8 inches and compacting each lift with at least eight passes of a vibratory steel wheel roller. It also requires covering the sides and top of the embankment with natural soil, at least 3 feet vertically and 8 feet horizontally, and installing drains at 50-foot intervals on both sides.Reusing foundry sand offers an alternative to conventional fillFoundry sand is used to make the molds in which metal parts such as engine blocks are cast. After repeated use, it wears out as its particles become rounded, and the foundry must replace it. If its characteristics and environmental suitability meet the required criteria, the sand can be reused in specific construction applications instead of being disposed of. The Ohio Environmental Protection Agency’s Beneficial Use Program sets requirements for using eligible industrial materials in approved applications.Any reuse must meet requirements that protect human health and the environment. The above-mentioned report lists a contractor bid of $8.60 per cubic yard for the delivered sand on the State Route 271 project. That price applied to this project only. It is not a current price, and it does not guarantee that foundry sand will always cost less than conventional fill. The report concluded that recycled foundry sand is an adequate material for highway embankments and is cost-effective when a project is near a foundry site.The repair highlights the value of testing and construction controlsThe State Route 271 repair shows how an industrial by-product can be used in highway construction once its properties have been evaluated. Testing established the sand’s suitability, and moisture control supported adequate compaction. Because the results describe this particular material, the project works best as one documented example, not as proof that foundry sand will perform the same way everywhere.You use AI every day. Now get your AI Quotient. Take the AIQ test.