Use of non-potable water in pavement construction: A laboratory study using seawater

Abstract

The Intergovernmental Panel on Climate Change (2018) projects that global warming is likely to reach 1.5°C above pre-industrial levels between 2030 and 2052. The effect of climate change on warmer temperatures and longer lasting drought periods has been well documented in Southern Africa. The Global Disaster Alert and Coordination System (2020) has declared an orange level (intermediate impact) drought for 6 months in South Africa and Lesotho making them water scarce countries. Construction processes rely on the use of potable water. In road construction, the moisture content is an important factor that affects the density of a road material. Due to the limited research in South Africa on use of non-potable water in road construction, there has been a greater need to conduct laboratory research. This paper highlights research through laboratory testing of granular sub-base material mixed with seawater obtained from the Indian Ocean. Aggregate originating from dolerite, tillite and sandstone rock quarries were used. Potable tap water was used as a baseline to the tests. Promising results are showed in the laboratory testing and it is advisable that further research is required going forward.