EFFECT OF SALT WATER IMMERSION ON THE DURABILITY OF A HOT ROLLED SHEET MIX

• Main Author: Syukri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2981
• Institution: Institut Teknologi Bandung

The durability of a bituminous mixture refers to its ability to resist the damaging effects of water and temperature. Loss of durability is a major factor in pavement deterioration. When designing a mix, durability is normally assessed in terms of the loss in strength following immersion for a relatively short period in water at elevated temperature. Such tests may not provide an accurate assesment of the effect of long-term exposure to water. In Indonesia, many roads in coastal areas are frequently inundated for long time periods by sea water at ambient temperature. This thesis describes an investigation of the effect of immersion in fresh water and in water containing 5%, 7.5% and 10% salt on the mechanical properties of HRS Class A mix. The mix was designed by Marshall analysis and tests performed on the mix at optimum bitumen content following immersion for periods of 10, 20 and 30 days were Marshall stability, indirect tensile strength and resistance to deformation in the wheel tracking test. The mix satisfied the conventional Bina Marga criterion on stability loss (25%) and this criterion was also met by samples immersed for 30 days in fresh water and in salt water at ambient temperature. The pattern for the stability and indirect tensile strength tests was identical. Samples immersed in fresh water showed a progressive reduction in strength with increase in time of immersion; samples immersed in salt water gained initially in strength and then showed significant strength loss when the immersion period was extended to 30 days. Deformation in the Wheel Tracking Test increased with increase in the period of immersion. On the basis of the second durability index proposed by Craus et al (1981), the most significant durability loss is indicated for samples immersed in fresh water. Salt content appear to have some influence on this parameter; loss in durability increases with increase in salt concentration.