Sustainability Assessment of Precast Ultra-High Performance Fiber Reinforced  Concrete (UHPFRC) Cantilever Retaining Walls

Yen Lei Voo,M.R. Raizal Saifulnaz,Behzad Nematollahi

doi:10.19026/rjaset.7.756

Abstract

This study evaluates the environmental impacts of a newly designed precast Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) cantilever retaining wall as a sustainable alternative approach compared with the conventional precast Reinforced Concrete (RC) cantilever retaining wall. Nowadays, according to the shocking reports of many researchers worldwide global warming is one of the most devastating problems of human being. To date, lots of research has been undertaken in the concrete industry to tackle this issue through reducing the environmental footprints of our structural designs. In this regard, UHPFRC technology offers substantial benefits through efficient use of materials as well as optimization of the structural designs resulting less CO_2 emissions, Embodied Energy (EE) and Global Warming Potential (GWP). UHPFRC as a sustainable construction material is mostly appropriate for the use in the fabrication of precast members such as precast concrete cantilever retaining walls. This study demonstrates the overview of the designed precast concrete cantilever retaining wall manufactured from UHPFRC and its Environmental Impact Calculations (EIC) versus the conventional precast RC cantilever retaining walls. Based on the EIC results, the precast UHPFRC cantilever retaining walls are generally more environmentally sustainable than those built of the conventional RC with respect to the reduction of CO_2 emissions, EE and GWP. In summary, the precast UHPFRC cantilever retaining wall proposed in this study is an alternative sustainable solution compared with the conventional precast RC cantilever retaining wall which can be used in many civil engineering projects.

Highlights

Nowadays, there are many concerns worldwide over the environmental impacts such as CO2 emission, Embodied Energy (EE) and Global Warming Potential (GWP) of our structural designs due to the increased public understanding of the devastating effects of global warming
One of the solutions to achieve this goal is through Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) technology that provides significant advantages in terms of aesthetic, workability, durability, ductility and sustainability
The structural design of the stem, heel and toe of the wall were undertaken based on the first principles in Drawings of the precast UHPFRC cantilever retaining wall: The proposed precast UHPFRC cantilever retaining wall consists of two integrated thin panels which act as the base panel and the vertical wall panel

Summary

INTRODUCTION

There are many concerns worldwide over the environmental impacts such as CO2 emission, Embodied Energy (EE) and Global Warming Potential (GWP) of our structural designs due to the increased public understanding of the devastating effects of global warming. The extremely durable nature of UHPFRC allows the UHPFRC structures to achieve much longer service life and almost negligible maintenance. This directly translates into the saving of cost and raw materials for re-construction (Nematollahi, 2012). UHPFRC known as Steel Fiber Reinforced Reactive Powder Concrete (SFR-RPC) is one of the main breakthroughs in concrete technology in the mid 1990’s It was introduced by Richard and Cheyrezy (1994, 1995) with compressive strength over 150 MPa and flexural strength over 30 MPa and remarkable improvement in durability compared to conventional concrete. The sustainability of the proposed UHPFRC wall is ascertained by comparing the Environmental Impact Calculations (EIC) of both walls with respects to material consumption, CO2 emission, EE and 100-year Global Warming Potential (GWP)

MATERIALS AND METHODS

Design method

AND DISCUSSION

CONCLUSION