MINIMIZING CRACKING IN CEMENT-TREATED MATERIALS FOR IMPROVED PERFORMANCE

This research describes the causes of pavement cracking, and investigates methods and materials that would minimize cracking and improve performance when using soil cement. A telephone survey of state highway agencies was conducted to gather data on the performance of in-service soil-cement pavements. This information was supplemented by performance data of soil-cement pavements in Mississippi, in-service pavement sections that are part of long-term pavement performance study, and cement-treated bases being built in three southern states. Analysis of condition data of pavements with cement-treated soil showed that some shrinkage cracks are inevitable in a cement base. However, crack-related degradation can be effectively mitigated by promoting numerous minute cracks in the base layer, in contrast to a few wide cracks. An analytical study was conducted to delineate factors that affect the desirable crack distribution. This model predicts crack distribution due to drying shrinkage. By limiting shrinkage potential of the soil-cement mix, crack-related degradation can be mitigated. Extended curing of a cement base inhibits potential cracks in the base. Adding fly ash to cement-treated soil reduces drying shrinkage of the mix and also creates desirable crack patterns. The results showed that to achieve an acceptable crack width limit, the maximum drying shrinkage should be limited to 525 microstrain for fine-grained soils and 310 microstrain for coarse-grained soils. The 7-day unconfined compressive strength for fine-grained soils should not exceed 350 psi (2.07 MPa). For coarse-grained soils, the 7-day strength should not exceed 450 psi (3.1 MPa).

Language

  • English

Media Info

  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 37 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00960733
  • Record Type: Publication
  • ISBN: 0893122092
  • Report/Paper Numbers: R&D Bulletin RD123,, R&D Serial No. 2404
  • Files: TRIS
  • Created Date: Jul 1 2003 12:00AM