Use of Scrap Tire Rubber in Controlled Low Strength Materials

Project Summary: This study was conducted to determine the effects of recycled scrap tire rubber on the engineering properties of controlled low strength material (CLSM). CLSM, also referred to as flowable fill, is used in applications where re-excavation is required.  Examples include backfills in trenches for utilities or pipelines, foundation supports, pavement bases, and various subbases and subgrades. Engineering properties of CLSM mixtures made of cement, fly ash, sand, and variable amounts of scrap tire buffings were determined. Comparisons were made between the properties of control CLSM (containing no rubber) and CLSM with varying amounts of rubber. Workability, early strength gain, and compressive strength were determined. Incorporating scrap tire rubber in CLSM mixtures provides a viable means to limit ultimate strength gain. Recommendations are provided for design of CLSM mixtures with rubber for effective construction (assessed through workability) and performance (assessed through strength) characteristics.

Principal Investigator: Dan Jansen and Jim Hanson

Funding Agency: Office of Naval Research

Cheung, T., Jansen, D. C., and Hanson, J. L. (2008), “Engineering Controlled Low Strength Materials Using Scrap Tire Rubber,” Proceedings of Selected Sessions of GeoCongress 08: Characterization, Monitoring, and Modeling of GeoSystems, ASCE GSP No. 179, Alshawabkeh et al., eds., ASCE, Reston, Virginia, p. 622-629.  [Download pdf]