Comparison of energy consumption, CO2 emissions between normal concrete and UHPC in rural bridge application

Abstract

Due to its outstanding mechanical properties and durability, Ultra High-Performance Concrete (UHPC) hasbeen gradually used for different types of structures in recent years. However, the analysis of environmental impacts and the assessment of the overall sustainability performance of UHPC applications is quite limited.This study presents the results of determining the total energy embodied and CO2 emissions causing the greenhouse effect of a rural bridge using UHPC compare to the normal concrete (NC) one by the life-cycle analysis (LCA) method. Environmental impacts are comprehensively considered at all stages from material production; materials and structures transportation; in-situ construction and installation; maintenance and repair during the service life; and finally demolished at the end of the project’s life. The analysis shows that the UHPC application in rural bridge construction can reduce the total volume of materials used by 40-58%, lower 65% total energy consumption and eliminate up to 76% CO2 emissions compared with a conventional concrete bridge. The results also confirm that using UHPC is a viable technical and eco-friendly option for rural bridge construction in Vietnam.

A Comprehensive Review of the Advances, Manufacturing, Properties, Innovations, Environmental Impact and Applications of Ultra-High-Performance Concrete (UHPC)

“…Three numerical examples of three different mixtures for calculating CO 2 emissions in the production of one cubic meter of UHPC are shown in Table 5. Using Equation ( 6), the first UHPC mixture mixed for a bridge in China [216] has 877 kg emissions of CO 2 /m 3 ; the second mixture, U0.20F2.5, mixed with fly ash and aeolian sand [224], exhibits 852 kg emissions of CO 2 /m 3 ; and the third mixture with fly ash, and silica powder and sand, used for a bridge in Vietnam [225], shows 1146 kg-CO 2 /m 3 . In Table 5, each mixture is presented in two separate columns with the weights of the materials used and their unit CO 2 emissions.…”