Evaluating the Performance of Bitumen Emulsion Stabilized Bases in Low Volume Sealed Roads:

A Case Study from Kiambu County (E443 Road)

Authors

  • Christine Mwongeli Nzai, Ms. University of Nairobi
  • Simpson Nyambane Osano, Dr. University of Nairobi
  • Paul Gacheru Macharia, Dr. University of Nairobi

Keywords:

Bitumen emulsion, evaluation, performance, specifications, stabilized

Abstract

This paper presents a study on the performance evaluation of Bitumen Emulsion Stabilized Gravel Base on E443 road in Kiambu County. Kenyan manuals and guidelines do not provide criteria for performance evaluation of bitumen emulsion stabilized materials (BESM). This research characterizes the road construction materials and investigates their influence on the BESM base, evaluates both the quality compliance of the as-built constructed BESM base and the performance levels of the BESM base road against road construction standards. This study concludes that there was noncompliance to subgrade and subbase specifications resulting to inadequate BESM base support, and nonconformity of as-built BESM base to mix design specifications affected the base elastic modulus. E443 Road performance was rated poor due to poor drainage, poor road surface and low layers’ elastic modulus. Comprehensive studies on construction materials characterization at 10-years design life, BESM mix design on gravel used and performance levels’ correlation are recommended.

Author Biographies

  • Christine Mwongeli Nzai, Ms., University of Nairobi

    Student, MSC Civil Engineering (Transportation)

  • Simpson Nyambane Osano, Dr., University of Nairobi

    Department of Civil and Construction Engineering

  • Paul Gacheru Macharia, Dr., University of Nairobi

    Lecturer, Department of Civil and Construction Engineering

References

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Published

2025-07-23

Issue

Vol. 20 No. 2 (2025): Highway Design, Urban Landscape and Affordable Housing Policy

Section

Articles