FLOWABLE FILL AS BACKFILL FOR BRIDGE ABUTMENTS

This study attempted to document the effectiveness of using a controlled low strength material (CLSM) as backfill for two county highway bridge abutments. The west ends of the two structures were constructed with the CLSM, while the east ends were constructed with conventional granular materials/compaction methods. The CLSM used consisted of a mixture of foundry sands, Class C flyash, cement and water. It was hoped that the CLSM would eliminate the familiar "dip" in the road experienced by roadway users at the bridge deck/approach interface caused by the settlement of the conventional materials/compaction methods. The two bridge abutments were constructed in the fall of 1996 and monitored for performance for three years. The evaluation consisted of taking levels of both sides of both structures twice a year and comparing the profiles for settlement. In this case study, the data collected and plotted on graphs indicate that the abutments that were constructed with CLSM showed tighter groupings than the abutments constructed with conventional materials/compaction methods, i.e., the CLSM showed superior settlement characteristics. However, the difference is not real significant, but it is promising, and in the case of the CTH G bridge, the performance was noticeably better as rated by five adults riding in a 1998 Dodge minivan driven over the structure at normal highway speeds. The subjects were not told which side of the bridge was constructed with CLSM and which side was constructed with conventional methods. All agreed the CLSM side showed superior performance in terms of a less pronounced dip in the road at the bridge deck/approach interface. A similar poll conducted on the CTH D structure was inconclusive. It must be noted, however, that both sides of both structures were patched with a 3/4 in. (1.9 cm) wedge of asphalt at one and two years after initial construction.

• Record URL:
  • http://wisdotresearch.wi.gov/wp-content/uploads/wi-16-99flowablefill1.pdf
• 
• Corporate Authors:

  Wisconsin Department of Transportation

  Bureau of Highway Construction, 3502 Kinsman Boulevard
  Madison, WI  United States  53704

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Wilson, J
• Publication Date: 1999-12

Language

• English

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: 29 p.

Subject/Index Terms

• TRT Terms: Backfill soils; Bridge abutments; Cement; Data collection; Fills; Flowable fill; Fly ash; Foundry sand; Monitoring; Performance; Settlement (Structures)
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls; I42: Soil Mechanics;

Filing Info

• Accession Number: 00789824
• Record Type: Publication
• Report/Paper Numbers: WI-16-99,, WisDOT Study # 99-05,, Final Report
• Files: TRIS, USDOT, STATEDOT
• Created Date: Mar 21 2000 12:00AM