Design Service Life of RC Structures with Self-Healing Behaviour to Increase Infrastructure Carbon Savings.

Ana Bras,John Milan Van Der Bergh,Hazha Mohammed,Ismini Nakouti

doi:10.3390/ma14123154

Ana Bras, John Milan Van Der Bergh + Show 2 more

Open Access

https://doi.org/10.3390/ma14123154

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Abstract

Corrosion of reinforced concrete (RC) structures costs the UK GBP 23b annually and is one of the main durability problems contributing to the development of rust, spalling, cracking, delamination, and structural deterioration. This paper intends to demonstrate the benefit of using tailored self-healing bacteria-based concrete for RC corrosion minimisation and service life increase. The purpose was to evaluate the enhancement in the lifespan of the structure exposed to a harsh marine microenvironment by utilising a probabilistic performance-based method. Comparison is made with the performance of a commercially available solution and in terms of embodied carbon impact. Three different concretes, using CEM I 52.5N, CEM II/A-D, and CEM III/A, were tested with and without an iron-respiring bioproduct (BIO) and an added admixture corrosion inhibitor (AACI). Results show that bioproduct significantly contributes to service life increase of RC structures with CEMIII/A. The repair solution with self-healing behaviour not only increases RC service life, but also enables us to decrease the required cover thickness from 60 mm to 50 mm in an XS2 chloride environment. In both XS2 and XS3 environments, a comparison of CEMIII/A+BIO and CEMII/A-D+AACI concrete shows the benefit of using bioproduct in corrosion inhibition context, besides contributing to an embodied carbon reduction of more than 20%.

Highlights

Materials mixes of concrete with and without bioproduct or added admixture corrosion inhibitor (AACI) were studied as it relates to In the laboratory, three distinct compositions of concrete were manufactured in order water absorption via capillary, a rapid non-steady state chloride test, and the surface to simulate the actual characteristics of concrete that can be used in the reinforced concrete (RC) structures reelectrical resistivity
A study was implemented to analyse the benefit of an iron-respiring bioproduct used to create self-healing behaviour in concrete in order to minimise corrosion in structures in maritime environments
The results show that the bioproduct had a significant contribution to the increase of the service life of RC structures with CEM III/A

Summary

Introduction

High labour costs related to infrastructure maintenance are incurred; on the other hand, damage to nature may typically be self-healed, and the durability of structures increased; learning from nature is crucial Such impacts on infrastructure occur globally, for instance, in India, where RC corrosion costs between 3–4% of the annual national gross domestic product (with an upward trend due to increased construction levels and lack of regulation). The design of minimum material instead of minimum cost could significantly reduce the construction materials used in buildings and structures, which would result in an analogous decrease in embodied carbon emissions This would contribute to the minimisation of the gap between the designed and real behaviour of a structure or building

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