Evaluating Life-Cycle Unit Costs of Traditional Cement Concrete and New Polymer Concrete Manholes in Wastewater Systems

Abstract

Wastewater manholes are crucial infrastructure components in sewage systems. They provide necessary access points for inspection and maintenance. However, limited studies were conducted on the life-cycle cost analysis of manholes. The primary objective of this study is to compute and compare the Life-Cycle Unit Cost (LCUC) of cement concrete and polymer concrete manholes to identify a cost-effective alternative for public agencies. To achieve the objective, this study analyzed commonly used 1.83 m diameter manhole data; 343 cement concrete manhole and 88 polymer concrete manhole cost data were collected from the Clark County Water Reclamation District (CCWRD), Las Vegas, Nevada, United States. The results show that the initial costs of polymer concrete are higher than those of traditional cement concrete. Statistical tests were conducted to determine the group differences. The findings show that the LCUCs of polymer concrete manholes are significantly cost-effective when compared to traditional cement concrete manholes. Public agencies can utilize polymer concrete manholes to save costs in future water and wastewater pipeline manhole construction projects.