Mitigation of Bridge Approach Settlement Using Recycled Rubberized Controlled Low-Strength Material

Scrap tire disposal is a major environmental challenge around the world. Highway agencies have been encouraged to promote solutions to reduce the accumulation of this troublesome waste material. This paper presents a novel alternative using recycled crumb rubber as a controlled low strength material (CLSM) mitigating bridge approach settlement. Laboratory tests performed to assess the engineering properties of CLSM consisted of various ratios of recycled rubber fines and native sand. Test results revealed that rubberized CLSM was not flowable without the addition of sand. Acceptable strength was not achieved until the inclusion of an appreciable amount of cement and water. As a result, the lightweight rubberized CLSM consisting of rubber fines alone can be used only as a low strength backfill at locations where settlement is critical. The replacement of sand in a rubberized CLSM caused flowability and strength to increase markedly with the increase of the sand content. The improvement can be attributed to increased water demand, the development of a stronger hydrated cement paste transition zone, and a denser particle packing within the sand-rubber mixture. Based on the results of this investigation, rubberized CLSM with a 40% sand replacement was used to rehabilitate a damaged bridge approach. Site experience demonstrated that the beneficial reuse of crumb rubbers as CLSM can be a practical solution to mitigate bridge approach settlement.


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References;
  • Pagination: 18p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01046296
  • Record Type: Publication
  • Report/Paper Numbers: 07-2066
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 6:46PM