Fatigue And Stability Characteristics Of Open Porous Cement Base Material

As large cities experience rapid growth, greater pressure is placed on existing infrastructure, in particular the construction and maintenance of roads and highways. ‘Permeable pavements’ are an economical and sustainable alternative to mitigate problems associated with current road structures. They allow water to percolate through the road structure reducing the impact of rainfall events, filtering of the stormwater, and provide a method of harvesting water whilst withstanding low to medium traffic volumes. Permeable pavements have become well established in the past thirty years in many countries around the world. However, its development and application has been limited in Australia as no national guideline from Austroads exists. The objective of the research summarised in this paper is to determine the structural and hydraulic performance of open porous cement stabilised materials. It is concerned with understanding the fatigue properties of cement stabilised permeable materials under real traffic conditions. In an attempt to fully understand the properties of the material, laboratory testing has been carried out to determine structural and hydraulic properties. These included the tensile and compressive strength, permeability, grading, effective void ratio, flexural stiffness and Young’s modulus. These tests were carried out on a group of samples with different aggregate sizes and shape to understand the relationship between the strength of the permeable material and the hydraulic parameters. Based on the results achieved, in obtaining optimum structural outcomes a balance needs to be established between structural and hydraulic properties. Further, based on fatigue characteristic of the samples, it was concluded that permeable stabilised material can withstand five million fatigue cycles without excessive cracking and deformation to the pavement structure. Hence, for low to medium traffic conditions, permeable pavements are a practical alternative to current impermeable design.