Submitted Successfully!
To reward your contribution, here is a gift for you: A free trial for our video production service.
Thank you for your contribution! You can also upload a video entry or images related to this topic.
Version Summary Created by Modification Content Size Created at Operation
1
Neel Renne
 -- 7096 2022-10-13 11:08:40 |
2 Part to the dicription is added
Neel Renne
 + 28 word(s) 7124 2022-10-13 11:12:21 | |
3 layout
Camila Xu
 + 1148 word(s) 8273 2022-10-14 03:24:31 | |
4 layout
Camila Xu
 + 2 word(s) 8275 2022-10-14 03:42:52 | |
5 layout
Camila Xu
 Meta information modification 8275 2022-10-21 08:07:45 | |
6 layout
Camila Xu
 Meta information modification 8275 2022-10-21 08:08:38 |

Video Upload Options

Do you have a full video?
Send video materials Upload full video

Confirm

Are you sure to Delete?
Yes No
Cite
If you have any further questions, please contact Encyclopedia Editorial Office.
Renne, N.;  Maeijer, P.K.D.;  Craeye, B.;  Buyle, M.;  Audenaert, A. Sustainable Assessment of Concrete Repairs. Encyclopedia. Available online: https://encyclopedia.pub/entry/29115 (accessed on 01 July 2024).
Renne N,  Maeijer PKD,  Craeye B,  Buyle M,  Audenaert A. Sustainable Assessment of Concrete Repairs. Encyclopedia. Available at: https://encyclopedia.pub/entry/29115. Accessed July 01, 2024.
Renne, Neel, Patricia Kara De Maeijer, Bart Craeye, Matthias Buyle, Amaryllis Audenaert. "Sustainable Assessment of Concrete Repairs" Encyclopedia, https://encyclopedia.pub/entry/29115 (accessed July 01, 2024).
Renne, N.,  Maeijer, P.K.D.,  Craeye, B.,  Buyle, M., & Audenaert, A. (2022, October 13). Sustainable Assessment of Concrete Repairs. In Encyclopedia. https://encyclopedia.pub/entry/29115
Renne, Neel, et al. "Sustainable Assessment of Concrete Repairs." Encyclopedia. Web. 13 October, 2022.
Sustainable Assessment of Concrete Repairs
Edit
This entry is adapted from the peer-reviewed paper 10.3390/infrastructures7100128

In order to improve the sustainability of concrete structures and repairs over their life cycle, life cycle assessment (LCA) and life cycle cost analysis (LCCA) should be applied. Life cycle assessment (LCA) is a holistic method to determine the environmental impact of a product or process with a systematic set of procedures for compiling and examining the inputs and outputs of materials and energy during the entire life cycle. A life cycle is the interlinked stages of a product or service system, from the extraction of natural resources to final disposal (cradle-to-grave). LCCA is a systematic or analytical method to determine the economic performance of a product or process during the entire life cycle, when the initial cost is taken into account, along with future cash flows incurred throughout the lifespan over a predefined period of analysis. The future cash flows are often taken into account by discounting, which compares costs and revenues at different stages in time and emphasizes the importance of present cash flows rather than future ones due to inflation and the earning power of money.

corrosion concrete damage repair rehabilitation life cycle assessment (LCA) life cycle cost analysis (LCCA)

1. Introduction

The European construction industry reached a peak in the manufacturing of reinforced concrete (RC) structures in the 1960s and 1970s. To date, the majority of these structures is either approaching or has already reached the end of their expected service life. Consequently, the need for maintenance and repair is high. Due to the continued deterioration of the existing building inventory and infrastructure, a large volume of concrete repair is expected [1]. To make it more tangible, it has been estimated that approximately 50% of Europe’s annual construction budget is spent on refurbishment and repair, which confirms the importance of sustainable concrete repair [2]. Moreover, the construction sector uses about 50% of the Earth’s raw materials and produces 50% of its waste [3][4]. Besides, the carbon emissions and energy demand associated with concrete use are mostly attributable to cement production and represents 5 to 8% of the total CO2 emissions from human activities and approximately 12 to 15% of the total industrial energy demand [3][5][6]. Lastly, it is also known that the construction sector of the EU is the largest consumer of natural resources and the largest producer of waste at the same time. These facts ask for more circular and environmentally friendly approaches in the construction sector to achieve the transition towards a circular economy (CE). According to the definition of the European Commission, a circular economy aims to maintain the value of products, materials, and resources for as long as possible by returning them into the product cycle at the end of their use, while minimizing the generation of waste [7]. Hence, conforming to the vision on CE, service life extension and the reuse of elements is crucial to reduce the environmental impact, as fewer products are discarded and fewer new materials are extracted. Concrete can be a durable material with a satisfactory performance over an acceptably long service life period. Nevertheless, numerous deterioration processes can affect all structures and materials, especially if preventive maintenance is not applied. This fact confirms the need for a through-life maintenance/repair management approach for RC structures in order to maximize the service life and delay the need for the demolishing of damaged RC structures. The latter is not desirable in light of the principles of the sustainable and circular economy and confirms the high value of service life extension.
Damage to RC structures can be related to defects in concrete or to reinforcement corrosion. The former can have many causes like mechanical, chemical, physical, or accidental (e.g., fire related, blasting, impact, etc.) [8]. Yet 50 to 80% of the damage to RC structures is induced by reinforcement corrosion initiated by the carbonation of the surrounding concrete and/or chloride ingress [9][10]. Therefore, corrosion control is one of the most important considerations that impact the durability of concrete [1]. Corrosion affects the durability of RC structures and is usually manifested in the form of concrete damage (i) cracking, the spalling of the concrete cover caused by the expansion of corrosion products around the reinforcement (Figure 1), and (ii) a reduction of the cross-section of the rebars with a reduced bearing capacity of the element as a consequence. The concrete cover is the main protective mechanism against weather and other aggressive effects. When the concrete cover is damaged, the reinforcement steel diameter reduction increases, eventually resulting in a decrease or loss of structural safety. This phenomenon is more critical in the case of pitting corrosion, as one of the most destructive localized forms of corrosion, initiated by chlorides, compared to uniform corrosion due to carbonation [11].
Figure 1. Examples of concrete spalling due to reinforcement corrosion.
In light of the principles of the circular economy, demolishing damaged RC structures is not desirable. This has been confirmed by several studies rating rehabilitation more environmentally friendly than rebuilding [12][13]. In addition, in the recently published paper about balconies, researchers have shown that demolishing and rebuilding had the highest LCCA/LCA score [14]. Therefore, repair and maintenance to extend the technical service life should be the first priority. In this context, concrete repair and the main deterioration caused by reinforcement corrosion indicate the relevance for the determination of an optimal repair method regarding corrosion-caused concrete damage. The application of an appropriate repair method for the occurred damage is important to ensure the intended service life extension. Concrete repair could have a limited service life extension in case of poor design or execution or due to the lack of inspection prior to the repair. This can lead to insufficient repair and the fast reappearance of damage (e.g., due to the halo-effect) after a relatively short time, further increasing their life cycle cost [15]. Qu et al. [16] highlighted the importance to detect and determine the cause of corrosion before any solution is selected to repair or reduce corrosion. Defining the repair strategy prior to the diagnosis and condition assessment of the existing concrete structure is something that should be avoided at all times. Regarding corrosion damage, there are several concrete repair methods available to prevent or stop the corrosion process: preserving or restoring passivity, increasing resistivity, cathodic control/protection (CP), and the control of anodic areas [8]. It must be noticed that CP has been applied to concrete structures worldwide for more than 25 years [15][17][18].
Currently, the selection of a repair method is mostly done based on technical requirements and initial cost, but without a life cycle perspective on costs nor on environmental impact. However, besides this classic approach, the induced impact on the environment should be also considered along with the life cycle of the structure [19]. Wang [20] studied the repair of concrete tunnels and also highlighted the importance of further studying the integration of the economic and environmental effects within the maintenance and/or repair strategy. In order to determine an optimal repair method taking into account both criteria, life cycle assessment (LCA) and life cycle cost analysis (LCCA) should be applied. LCA is a holistic method to determine the environmental impact of a product or process with a systematic set of procedures for compiling and examining the inputs and outputs of materials and energy during the entire life cycle [21]. A life cycle is the interlinked stages of a product or service system, from the extraction of natural resources to final disposal (cradle-to-grave). LCCA is a systematic or analytical method to determine the economic performance of a product or process during the entire life cycle, when the initial cost is taken into account, along with future cash flows incurred throughout the lifespan over a predefined period of analysis [22]. The future cash flows are often taken into account by discounting, which compares costs and revenues at different stages in time and emphasizes the importance of present cash flows rather than future ones due to inflation and the earning power of money [22]. Therefore, present and future costs or revenues cannot be compared without considering the opportunity value of time. The latter can be defined as the economic return that could be earned on investments (e.g., funds) as the best alternative [23]. The discount rate, which takes this opportunity value of time into account, is used to adjust future cash flows into the present. Hence, choosing the most appropriate discount rate is a critical step as it is dependent on the cost of required investments, the anticipated level of risk, and the opportunity cost (benefits that are missed out when choosing one alternative over another) of the investment.
A life cycle approach based on LCCA and LCA has a wide range of benefits compared to short-term decisions, e.g., considering the effect of choices, avoiding problem-shifting to another life cycle phase, maximizing the potential of RC structures instead of just patching up, etc. For concrete structures, Matos et al. [24] illustrated the applicability and advantages of using LCCA. Namely, the best repair strategy of several alternatives can be chosen due to a comparison of costs over the entire life cycle. Therefore, the integration of LCCA is necessary to achieve a comprehensive and long-term analysis, which positively affects the returns on investment. Hájek et al. [25] and Vieira et al. [26] emphasized the importance of subjects like performing a detailed LCA using data sets with local relevance and the need for more attention for the lack of a holistic assessment of environmental impacts, the lack of applications that consider regional and technological variations, and the neglection of life cycle phases. However, a rigorous life cycle analysis is not always feasible, particularly in regions where the exact economic and environmental data are not available [27]. Besides, several other studies have indicated the high value and holisticness of these methods, which shows the valuable application of supporting the decision-making process [28][29][30][31].
The service life has a major impact on the results of a LCA and LCCA and could lead to a wide range of results [32][33]. In order to take the appropriate service life (extension) into account, it is important to determine it in an accurate way. In most cases, an approximate service life based on other research, manufacturers’ data, or empirical analysis of in situ performance is used for service life estimations [34]. However, this will often result in inaccurate results due to varying in situ life spans compared with the considered ones for the analysis. The service life of a concrete repair is dependent on the materials’ properties, material and system composition, quality of design and installation, damage mechanisms, expected maintenance regimes, and climate and exposure [32][34]. In order to determine the (extended) service life of RC structures susceptible to corrosion and their repair, predictive models could be used to describe corrosion initiation, propagation, and the corresponding deterioration by a probability of failure [35].

2. Sustainability Assessment

The amount of research work done with regard to the concrete repair/maintenance decision-making process through LCCA and particularly LCA is rather limited. Namely, almost no LCA studies exist that consider the environmental impact of system repair, while, due to the high number of structures, renovations will be a key factor in the future of the European building sector [36][37]. However, when studies exist, they mostly only include one of the two assessment methods and consider a limited number of repair methods. 

2.1. Assessment through LCA and LCCA

Overall, LCA and LCCA studies mainly focus on the material level, e.g., “green concrete” [38][39], or on material choices during the design phase [40][41]. However, in order to get a better idea about (1) the incorporation of LCA and LCCA during concrete repair selection and (2) the drawbacks and benefits of these methods, the selected references are discussed.
To start with, based on Table 1, the publication evolution over the past decades and where the researchers are situated is visualized in Figure 2. The gathered data represent results from papers conducted in over 22 countries. Most research reported in international publications is done in Europe, followed by North America, but results from countries like China, India, Iran, Japan, Korea, and Brazil are present as well. The first publication originates from 2001, but the investigations on the subject remained limited for several years. However, in the past decade, a high increase in the number of papers can be seen. This indicates the popularity of the subject and, consequently, the relevance and need of/for concrete repair.
Figure 2. Situating papers about concrete repair in time and geographically.
Table 1. Overview of state-of-the-art sustainability assessment concrete repair through LCCA and LCA.
LCCA LCA Ref. Subject Source
Type		 Year Country [42] Case Study Corrosion Repair Technique SL Pre-Diction LCCA
Method		 LCIA
Method		 Relevance
                  CC CR PR cSC rSC IM CP CE ER RD CI HA        
General
✓ ✓ [43] Types of sustainability assessments applied to ‘maintenance’ interventions using concrete- or cement-based composite materials. RP 2021 DE +– + + + + + + + + – – – – – Overview Overview Overview 5
✓
(limited)		 ✓
(limited)		 [27] An alternative to a LCCA named the repair index method (RIM), which enables the possibility of including other non-technical requirements that would be difficult to quantify in a LCCA. JP 2003 ES – ++ – – + – – – + + + – + + SLA RIM RIM 5
✓ – [44] Investigation of the time-dependent capacity of a corroded circular RC column by using nonlinear finite element analysis. JP 2019 IR + ++ + – – + – – – – – – – – ++ n.m. – 2
✓ – [24] Overview of the ongoing works for a state-of-the-art report (bulletin) regarding LCCA analyses of concrete assets. CP 2018 DK +– – – – – – – – – – – – – – – – – 3
✓ – [45] Assessment of the performance of CP systems in practice with information on 150 reinforced concrete structures (RCS). JP 2014 NL – ++ – – – – – – ++ – – – – – +–
(SLA)		 NPV – 3
✓ – [46] Market study on the performance and LCCA of CP using galvanic anodes in RCS in India and worldwide. JP 2021 IN + ++ – +– + – +– – ++ – – – – – SLA FV – 3
✓ – [47] Study on the concrete carbonation in the presence of repair materials using the maintenance periods and repair cost according to the coefficient of variation (CV) of the carbonation depth. JP 2020 USA – ++ – – – + – – – – – – + – ++ Repair cost only – 4
✓ – [48] Determination of important life cycle variables: expected time lost in repairs, reliability of the system, and the cost of operation and failure. JP 2014 USA + + – – – – – – – – – – – – ++ – – 3
– ✓ [25] General discussion on LCA application to concrete structures + case study floors. JP 2011 CZ + – – – +– – – – – – – – – – SLA – m.i.s. 2
– ✓ [26] Literature review conducted to present the state-of-the-art of LCA methodological practices in the manufacturing of common concrete and concrete with aggregates derived from recycled waste. RP 2016 BR +– – – – – – – – – – – – – – Overview – Overview 2
– ✓ [49] Probabilistic sustainability framework for the design of concrete repairs and rehabilitation to achieve targeted improvements in quantitative sustainability indicators. JP 2014 USA + + + – – – – – – – – – – – ++ – ReCiPe
TRACI
EI 99		 5
– ✓ [50] Framework and methodology for quantifying the ecological effects and impacts from various methods and systems for the repairs and maintenance of concrete structures (CS). CP 2001 NO + + – – + + + – – – – – – + SLA – m.i.s. 5
Buildings
CCO ✓ [40] Influence of design strategies on the economic and environmental performance of 30-story residential RC building. JP 2018 BR ++ – – – – – – – – – – – – – – n.m. CML 2
✓ limited [13] Assessment of the cost/benefit ratio for total demolition vs. refurbishment on a 40-year-old detached single house. JP 2013 PT ++ – – – – – – – – – – – – – SLA CBA MF
EE		 2
✓ ✓ [12] Literature review: compares different LCA works for refurbished and new buildings + real LCA and LCCA case study for a classified ancient building. RP 2015 PT + – – – – – – – – – – – – – RP: Overview
Case: SLA		 RP: Overview
Case: Sum		 RP: Overview
Case: m.i.s.		 3
✓ – [51] Probabilistic assessment method of service life and life cycle maintenance strategies + reliability function of structural safety performance based on hazard rate/function of a deterioration RC building during a rare earthquake. JP 2010 JP + ++ – +– + + – – – + – – – – ++ NPV – 3
– ✓ [37] Summary of the recent contributions related to the environmental evaluations of building refurbishment and renovation using LCA. RP 2017 ES +– +– – – – + – – – – – – – – +– – Overview 4
– ✓ [36] New approach to estimate building lifespans based on their structures durability (degradation models of reinforced concrete structures) + refurbishment versus demolition and new building evaluated from an environmental point of view. JP 2019 ES + + – – – – – – – – – – – – + – GWP 5
Civil infrastructure (Bridges, tunnels, …)
✓ ✓ [52] A framework for the maintenance-scheme optimization of existing bridges based on the genetic algorithm (GA). JP 2018 CN + +– – – +– +– – – – – – – – – + NPV EI 99 2
✓ ✓ [53] Evaluation of (the economic and environmental impacts of) 18 different design alternatives for an existing concrete bridge deck exposed to chlorides. JP 2019 ES ++ ++ + – – + + – + – – – + + + NPV ReCiPe 2008 3
✓ – [20] Methods and technology for concrete repair, waterproofing work, tunnel rehabilitation, and eco-efficient repair + tunnel performance evaluation. JP 2018 JP – + – – + + – – – – – – – – + NPV – 2
✓ – [54] Probabilistic and deterministic LCCAs for an entirely FRP-reinforced concrete bridge and a conventional RC prestressed concrete (PC). JP 2021 USA +– ++ – – + – – – + – – – – – SLA NPV – 2
✓ – [55] Probabilistic framework to estimate the LCCA associated with bridge decks constructed with different reinforcement alternatives. JP 2021 USA + ++ + +– +– – + – – – – – – – + NPV – 2
✓ – [56] Describes an approach for agencies to enhance bridge investment decisions. JP 2015 SE + – – +– +– – – +– – – – – – – SLA NPV
EAC		 – 3
✓ – [57] Development of a rational method for the most cost-effective intervention schedule for bridges, where the structural safety is maintained with the minimum possible LCCA. JP 2018 CA + + + – + – – – – – – – – – + EAC – 3
✓ – [58] LCCA for various options to prevent or remediate corrosion damage in an example bridge exposed to de-icing salts, locally aggravated by the leakage of expansion joints. JP 2016 NL ++ ++ – + – + – – + – – – + + SLA NPV – 3
✓ – [59] Framework for the prediction of deterioration. JP 2010 JP + ++ – – + – – – + – – – – – + Sum – 3
✓ – [60] Overview of recent research about life cycle engineering for civil and marine structural systems and future research directions. JP 2016 USA – + – – – – – – – – – – – – + CBA – 4
– ✓ [61] Potential for using a self-healing engineered cementitious composite (SH-ECC) for the rehabilitation of bridges. CP 2018 BE – +– – – – – – – – – – – – – SLA – GWP 1
– ✓ [62] Comparison of the different solutions for bridge rehabilitation from an environmental point of view. JP 2013 FR + – – + – + – – – – – – – – SLA – GWP (CML) 1
– ✓ [63] Comprehensive LCA to study the environmental impact of interventions on an existing bridge using PE-UHPFRC. JP 2019 CH + + – – – + – – – – – – – – SLA – m.i.s. 1
– ✓ [64] Analysis of the environmental implications of several prevention strategies through a LCA using a prestressed bridge deck as a case study. JP 2018 ES ++ ++ + + + + + + – – – – – + + – EI 99
EPS
ReCiPe		 3
– ✓ [65] Probabilistic service life prediction models for determining the time to repair + probabilistic LCA models for measuring the impact of a repair. JP 2020 USA + + – + – – – – – – – – – – ++ – TRACI
ReCiPe		 4
– ✓ [66] Service life prediction models combining deterioration mechanisms with limit states + LCA models for the impact of a given repair, rehabilitation, or strengthening. CP 2011 USA – +– – – – – – – – – – – – – + – n.m.
(GWP)		 4
Pavements
✓ ✓ [67] Investigate the environmental, economic, and social impacts of the three most widely adopted rigid pavement choices through LCA. JP 2016 USA + +– – – – – – – – – – – – – SLA NPV m.i.s. 1
✓ ✓ [68] Literature review repair of concrete pavements. RP 2018 USA +– +– – – + – – – – – – – – – Overview Overview m.i.s. 2
✓ – [22] Review of existing methodologies in the wider field of LCCA for road projects with a highlight on critical processes and the identification of hotspots in order to increase the robustness of LCCA. frameworks. JP 2020 BE – – – – +– – – – – – – – – – Overview Overview – 3
Others: more specific (floorings, columns)
✓ ✓ [41] Environmental and economic LCA of three different floor systems. JP 2018 UK ++ – – – – – – – – – – – – – SLA NPV TRACI 1
✓ ✓ [69] Evaluation of environmental impacts and costs of a structural element (slab) with varying of concrete cover thickness using LCA and LCCA. JP 2021 BR +– + – – – – – – – – – – – – + Sum CML4.4 2
✓ ✓ [14] LCA and LCCA of life-extending repair methods for RC balconies. JP 2022 BE ++ ++ – + + + + +– + +– – – – + SLA NPV ReCiPe v1.13 5
✓ – [70] Repair strategies are examined for their economical relevance to LCCA. CP 2013 AT + ++ + + + + – + + – – – – – + NPV – 4
– ✓ [71] Simplified methodology for the size strengthening of beams and to provide the application of LCA to the selected techniques. JP 2018 ES + + – – – – – – – – – – – – +– – CED
GWP		 1
Legend of symbols and abbreviations: ✓ = assessment method included; – = not included; +– = mentioned but not included/not expressly included; + = included; ++ = focused; RP = review paper; CCO = construction-cost-only; JP = journal paper; CP = conference paper; CC = concrete cover; CR = conventional repair; PR = patch repair; cSC = concrete surface coating; rSC = reinforcement surface coating; IM = impregnation; CP = cathodic protection; CE = electrochemical chloride extraction; ER = electrochemical realkanization carbonated concrete; RD = realkalization carbonated concrete by diffusion; CI = corrosion inhibitors; HA = hydrophobic agents; SL = service life; SLA = service life assumption; n.m. = method not mentioned; NPV = net present value; FV = future value; CBA = cost-benefit analysis; Sum = sum up without discounting; EAC = equivalent annual cost; m.i.s. = manual indicator selection; EE = embodied energy; MF = material flow; EI = ecoindicator; GWP = global warming potential; CED = cumulative energy demand; ReCiPe, EI, Traci, CML, and EPS are standard LCIA methods.
Subsequently, the 10 references that consider (in limited ways) the two methods for concrete repair in their research are reviewed [12][13][14][27][43][52][53][67][68][69]. Scope et al. [43] explored and synthesized the sustainability potential of maintenance and repair methods using concrete- and cement-based composite materials in a review article. However, there is no sufficient information provided on repair techniques specific for corrosion-caused concrete damage. Therefore, the paper cannot recommend any particular repair technique in general based on their literature review. Nevertheless, according to Scope et al. [43], there is a trend towards more holistic types of assessment; environmental and economic sustainability dominates, with global warming and energy consumed being the most often reported. In addition, the importance of long-term orientation and life cycle thinking for sustainable maintenance strategies is highlighted.
Ferreira et al. [12] and Gaspar and Santos [13] investigated whether refurbishing an existing structure is environmentally and/or economically profitable compared to new construction based on a case study. The former indicated that refurbishment is environmentally beneficial compared to a new equivalent construction [12]. However, the gains were not as high as commonly suggested, mainly due to the massive use of structural steel and shotcrete. In this case study, an earthquake-safe building needs to be achieved, causing the need for a high amount of extra material. In contrast, as far as cost is concerned, refurbishment was found to be less competitive due to the high construction cost for seismic and structural strengthening, which are very intrusive works. Therefore, in this case, additional solutions should be developed, and financing facilities should be studied that could support refurbishment works. In addition, whether the highest impact contribution is due to labor or materials is not clarified by the paper. Moreover, Gaspar and Santos [13] reported a similar building cost but a lower environmental impact for refurbishment compared to new construction. This can be explained by a lower cost in terms of materials for refurbishment, but the larger building period and better-skilled workforce due to the complexity of the building process. The environmental advantage can be explained by less matter, embodied energy consumption, and demolition waste.
Moreover, Xie et al. [52] and Navarro et al. [53] emphasized the need for preventive maintenance in order to reduce the cost and environmental impact over the life cycle of bridges. Maintenance optimization should result in significant reductions of life cycle impacts if compared to maintenance undertaken at the end of the service life. A well-considered initial time and time interval of periodic maintenance would effectively decrease the bridge’s life cycle environmental impact. However, the reduction of the life cycle cost of the bridge caused by maintenance-scheme optimization is not significant due to a discounting effect [52]. Navarro et al. [53] also evaluated different preventive bridge-design alternatives over 100 years, for which the following order was obtained for environmental impact (less beneficial first): stainless steel-galvanized steel-organic inhibitor-migratory inhibitor-ICCP-sealant product-hydrophobic treatment. For the economic cost, the order has some changes: galvanized steel-stainless steel-ICCP-organic inhibitor-hydrophobic treatment-sealant product-migratory inhibitor. The effect of the addition of silica fume, fly ash, and polymers and the effect of w/c ratio and concrete cover was also investigated for different scenarios. As these principles give very varying results according to their quantity, they are not further discussed. The difference between the impacts can be explained by the considered maintenance interval, used materials and processes, transport, etc. The optimization of the maintenance intervals reduces the economic and environmental life cycle impacts up to 13 and 19%, respectively, compared to essential maintenance.
Furthermore, Andrade and Izquierdo [27] developed a method to select repairs based on safety, serviceability, environmental impact, durability, and economy requirements, which they called the repair index method (RIM). A rating is given for each section based on four levels and is added to a total value after multiplying with a ranking of importance. Therefore, it is not a very transparent comparison but could be valuable when there is a good balance between the evaluation requirements. Another advantage is the possibility of incorporating non-technical requirements, as of the social and legal types. In the research, RIM is used to rate five repair options for corrosion-damaged RCS, which gave the following sequence from less to most beneficial: electrochemical treatment-inhibitors-cathodic protection-hydrophobic agents-patching. However, this is only a general rating and is not case specific. Lastly, the biggest drawback is that, by the incorporation of the environmental and economic impact in the same rating, objectivity is lost.

2.2. Assessment through LCA or LCCA

Ghodoosi et al. [57] concluded that frequent minor repairs reduce the life cycle cost by reducing the number of major costly repairs. The same conclusion is drawn based on LCA by the results of a study by Navarro et al. [64]. The importance of preventive maintenance was stated by a high number of studies, which is shown in Figure 3. In fact, 12 out of 42 (26 %) papers did this based on LCCA. Similarly, for LCA, 7 out of 42 (17 %) highlighted the same conclusion based on LCA. This shows why maintenance should be included from the beginning of the structure’s life span to reduce the economic and environmental impact. However, according to the research of Kumar and Gardoni [48], it may be more advantageous to have frequent repairs for a long-term service life, but for a short-term service life, it may not be advantageous or may even be disadvantageous. Therefore, the desired positive effects of an operation strategy take some time to take effect.
Figure 3. Visualization of the importance of preventive maintenance.
Wittocx et al. [14] emphasized the economic, as well as the environmental, impact of the advantage of refurbishment instead of demolishing and rebuilding. Palacios-Munoz et al. [71] also showed that strengthening is more environmentally sustainable than rebuilding a new structure, even in the case of damage. The suitability of a solution is, however, strongly depending on the characteristics of the original element. In their research, four strengthening techniques of RC beams are evaluated: carbon-fiber-reinforced polymer, reinforced concrete section increasing, steel placed with mechanical anchorages, and steel placed with epoxy resin. The first and third technique are indicated as the most sustainable if the main purpose is increasing the bending capacity and if no degradation is present. This is due to a reduction of the material requirements due to the higher mechanical properties and due to the avoidance of harmful epoxy resin. However, when degradation is present, the suitability of the solution strongly depends on the geometry of the beam. Increasing the reinforced concrete section is more suitable when a large increase in the bending capacity is required, rather than for low ones due to the high workload. For the life cycle cost, no extra studies evaluated refurbishment versus new construction beside the ones discussed in original context. Nevertheless, for the environmental impact, more papers evaluated this manner. More particular, six out of six studies (of Table 1) that investigated this through LCA indicted refurbishment was preferable compared to rebuilding (Figure 4). The same conclusion was emphasized by one study for LCCA. However, also for LCCA, one study concluded that there was an equal life cycle cost for (i) refurbishment and (ii) demolition and rebuilding. Once, refurbishment was indicated as less preferable regarding the life cycle cost. Therefore, it can be concluded that, in general, refurbishment is more sustainable regarding the environmental impact, but, for the economic impact, it is case-specific. The most important factor here is the labor intensity of the work.
Figure 4. Visualization of sustainability refurbishment vs. demolition + rebuilding (new).
Regarding the economic impact, the paper of Polder et al. [45] showed that the life cycle cost of CP systems on concrete structures can be predicted, taking into account failure rates based on field data. They concluded that the cost of the replacement of components is relatively small compared to the cost of inspection and electrical checkups. Besides, based on the life cycle cost of 30 repair projects, Krishnan et al. [46] confirmed that the use of a CP strategy can lead to life cycle-cost savings of up to about 90% about 30 years after the first repair. Consequently, CP and cathodic prevention (CPrev) are more beneficial from an economic point of view than PR. Furthermore, CP and CPrev strategies can enhance the service life to as long as needed by the replacement of anodes at regular intervals and at minimal cost (5% of the first repair).
Moreover, the total life cycle cost with preventive measures using stainless steel reinforcement, (repeated) hydrophobic treatment, and cathodic prevention in the joint areas of an example bridge are compared with conventional concrete repair and CP by Polder et al. [58]. Stainless steel reinforcement and the hydrophobic treatment of concrete were reported as the most preferable maintenance options for a life span from 35 to 100 years. For stainless steel, this can be explained by a higher initial cost but no need for maintenance at all. Hydrophobic treatment has an average initial construction cost but also a low cost during the other life cycles. However, for a shorter life span until 35 years, cathodic protection should be more preferable. The differences between the results of Polder et al. [58] and Navarro et al. [53] can be explained by the other configuration and size of the case study. Similarly, five types of repair methods for infrastructure RC structures (e.g., bridges) were compared by Islam and Kishi [59]: CP with a conductive polymer and with a titanium mesh, patching, and two types of overlays (i.e., concrete and hot mixed asphalt with a membrane). Patching should have the highest life cycle cost, whereas concrete overlay has the lowest. The high life cycle cost can be explained by the maximum variable cost of repair. Likewise, the lowest life cycle cost is due to a low variable cost and a longer life span of repair as well.
Farahani [44] investigated, using a nonlinear finite element analysis, the time-dependent capacity of a corroded round-shaped RC column. More particularly, the influence of several scenarios on the column’s performance due to chloride-induced corrosion was investigated. For the repair scenarios, five concrete surface coatings are included: acrylic-modified cementitious: type D (CPD); epoxy polyurethane (PU); aliphatic acrylic (AA); acrylic-modified cementitious: type E (CPE); and styrene acrylate (SA) The equivalent concrete cover thicknesses were calculated as: 14.4, 31.2, 38.9, 27.6, and 12.6 mm. With a cost of 85, 77, 55, 84, and 54 USD respectively, AA can therefore be indicated as the optimal concrete surface coating. In addition, four increasing concrete cover thicknesses (i.e., 10, 15, 20, and 25 mm) and using new longitudinal and horizontal reinforcements after the initial cracking of the concrete cover are also investigated as repair scenarios. Out of all repair scenarios, a 20 mm increasing concrete cover thickness adding to the initial concrete cover of 70 mm was found to be the most beneficial for a service life of 40 years.
Furthermore, Binder [70] analyzed the life cycle cost of a set of repair methods (i.e., concrete facing, patch repair, patch repair with hydrophobic impregnation, CP with titanium mesh, and CP with conductive coating) for chloride-contaminated columns. Patch repair with hydrophobic impregnation and cathodic protection with a titanium mesh turned out to be the most cost-effective strategy, taking into account the full service life extension (75 years) of the structural component. In contrast, patch repair only had a 40% higher value, resulting in the highest life cycle cost, mainly due to its low service life extension and, therefore, the high need for maintenance. Moreover, CP with a coating and a concrete overlay are the next repair options with increases in the life cycle cost of 35% and 16%, respectively, compared to the two most optimal options. Lastly, it is stated that the life cycle cost of the cathodic protection principle (CP-Mesh) could be further reduced by the optimization of the service life of the electronic components.
Cadenazzi et al. [54] compared two bridge design alternatives: reinforced bridge with traditional carbon steel (CS) vs. fiber-reinforced polymers (FRP). The life cycle cost includes (1) a direct cost that covers the initial construction cost and subsequent maintenance and repair and (2) a user cost covering losses due to traffic delay, work-zone crashes, and environmental impact. The CS alternative is found to be a high-risk design alternative with a higher cost spread and an increased life cycle cost of 30%. This can be explained by a more intensive maintenance strategy over 100 years, which overcomes the difference between the initial costs of the techniques. At CS, patch repair and cathodic protection are applied, while at FRP, only patch repair should be needed. Similarly, the life cycle cost of bridge decks constructed with different reinforcement alternatives is investigated by Shen et al. [55]. Results show that the concrete cover, chloride exposure condition, average daily traffic, and number of traffic lanes have a significant effect on the life cycle cost of reinforced concrete bridge decks, especially for those constructed with conventional reinforcement. In addition, they highlighted that conventional rebars provide the lowest direct cost for a service life up to approximately 28 years; afterwards, corrosion-resistant alternatives provide the lowest direct life cycle cost. This can be explained by the additional expenses associated with maintenance and repair actions for conventional reinforcement. Out of galvanized rebar, epoxy coated rebar, and martensitic micro-composite formable steel (MMFX) rebar applied at a case study, MMFX was found to have the lowest life cycle cost, which was approximately one-third of conventional reinforcement. Lastly, Safi et al. [56] show the high value of the implementation of LCCA in bridge procurement in order to indicate the most cost-efficient bridge design over its life cycle. Based on several case studies, the initial investment can differ by up to 50%, while the maintenance cost could generally differ by up to 15% between different designs. This highlights the advantage of considering a life cycle approach instead of only the initial construction cost. However, it is important to acknowledge that the science of LCCA is far from perfect. Its findings can be biased by the perceptions and forecasts of future costs, the reliability of the data used, the discount rates applied, the stages of the asset life cycle included in the analysis, and life cycle plans.
Regarding the environmental impact, patch repair with shotcreting and hydrophobic surface protection were compared by Årskog et al. [50]. It was pointed out that the impacts from the patch repair strongly exceed that of the hydrophobic surface protection: the use of energy (MJ/m2) is 21.6 times higher, global warming (kg CO2 eq/m2) is 46.9 times higher, acidification (g SO2 eq/m2) is 125 times higher, eutrophication (g SO2 eq/m2) is 126.8 times higher, and photo-oxidant formation (g Ethene eq/m2) is 5.5 times higher.
Furthermore, the global warming potential of bridge rehabilitation with different types of ultra-high performance fiber-reinforced concrete (UHPFRC) and the comparison of them with more standard solutions was investigated by Habert et al. [62]. A traditional rehabilitation system using conventional concrete (C30/37) plus a waterproofing membrane, and a rehabilitation system with UHPFRC solutions are analyzed. Regarding the latter, classic UHPFRC and ECO-UHPFRC with limestone filler as cement replacement are considered. Results show, over a service life of 60 years, a higher impact for the traditional system and UHPFRC compared with ECO-UHPFRC, with, respectively, an impact 40% and 28% higher. The lower impact compared to the traditional system can be explained by lower maintenance and repair volume needs. Moreover, the study shows that the impact due to the production of materials is the major contributor to the environmental impact whatever the rehabilitation systems used. Similarly, Hajiesmaeili et al. [63] showed, respectively, 55% and 29% decreases in the environmental impact of polyethylene (PE) UHPFRC compared with the replacement with a new traditional RC bridge and the conventional UHPFRC method. The considered impact categories are global warming potential (GWP), cumulative energy demand (CED), and ecological scarcity (UBP). In addition, Van den Heede et al. [61] compared the rehabilitation with self-healing engineered cementitious composite (SH-ECC) with ordinary Portland cement (OPC) concrete and UHPFRC repair. Considering a standard error distribution, OPC concrete had the highest environmental impact, followed by SH-ECC and UHPFRC, with lower values of 55–70% and 59–74%, respectively.

2.3. Service Life Prediction

According to the FIB Model Code [72], the “direct consequence of passing this limit state [of depassivation] is only that possible future protective measures for repair become more expensive”. For that reason, the limit state of depassivation is often associated with relaxed target probabilities of failure (P0), usually in the order of 1 to 12%, and in the design stage, P0 should be chosen as a function of the cost of repair (during the intended service life of the structure) relative to the cost of construction [73].
Focusing on concrete repair strategies, a general probabilistic sustainability design framework for the design of concrete repairs and rehabilitation is presented by Lepech et al. [66]. The framework consists of two types of models: (i) service life prediction models and (ii) LCA models. In this manner, the time to the first repair combining one or several deterioration mechanisms and the environmental impact of it can be determined. The relevance of such a framework in order to improve the quantitative environmental sustainability indicators is presented, but the need for more research still remains, to allow further implementation. In a follow-up paper, it was tested for a 40 mm and 80 mm deep concrete cover repair, of which the 80 mm was found the most sustainable over the lifespan (100 years) of the structure. The thicker repair has a higher impact but a greater durability, so the cumulative impact over the life cycle is reduced. This shows the importance of taking an appropriate service life into account and choosing the right intervention for an intended life span. A great deal of research still remains in the development and validation of methods and tools [49]. Moreover, the framework is further extended, and a new mathematical approach to simplify it is presented by Zirps et al. [65]. For probabilistic service life prediction models, they used Fick’s law, which is a simple method to approach the diffusion of chloride and does not capture all aspects of the complex nature of this process. The research showed that such a framework can provide an engaging tool for the sustainability-focused probabilistic design of reinforced concrete infrastructure.
Existing carbonation models predict service life based on deterministic theories, like, for example, in the study of Farahani [44]. Therefore, based on deterministic and probabilistic methods, Lee et al. [47] investigated concrete carbonation in the presence of repair materials using the maintenance periods and repair cost according to a CV of the carbonation depth. The CV value indicates the variability of the actual structure and the concrete quality. For the carbonatation depth, a carbonation probability equation is implemented using Monte Carlo simulations considering the carbonation depth distribution and the probability distribution of the cover thickness as random variables. Out of water-based paint, organic alkaline inhibitors, inhibiting surface coating, and corrosion-inhibiting mortar (CIM) as repair materials, CIM was found to be the best carbonation inhibitor. However, it has also the highest life cycle cost at the intended service life of 100 years due to a high residual life span. When, for example, a life span of 80 years is considered, CIM is by far the most beneficial option with a 2.4 to 3.1 times higher life cycle cost for the other repairs. Lastly, the difference between the deterministic and probabilistic LCCA models was highlighted. The probabilistic model will predict more efficient maintenance by adjusting the intended service life or selecting the appropriate repair material. Nevertheless, when the CV decreases, the probabilistic cost approaches the deterministic repair cost.
Thirdly, Palacios-Munoz et al. [36] evaluated the influence of the lifespan in a comparative LCA by considering three different approaches to determine the buildings’ lifespans: default value, statistical, and durability-based. Due to the common practice of considering a default value for lifespans, LCA involves a high risk of programmed obsolescence in the building sector. Therefore, statistical or durability-based determined lifespans are introduced in the paper. Palacios-Munoz et al. [36] mentioned that statistical studies of buildings’ lifespan provide the most realistic results. However, the results can be accurate in general terms but are not representative for the particular analyzed building. Lastly, corrosion due to carbonation is considered for the durability-based approach since it is the most frequent degradation phenomenon. The durability-based estimated value of lifespan has an uncertainty that derives from the degradation model due to simplification. So, it is important to simulate the degradation of the concrete structure accurately.
Moreover, Chiu et al. [51] developed a deterioration model to estimate the deterioration risk induced by chloride ingress resulting from failure and severe spalling or cracking during earthquakes. This method focuses on the probabilistic assessment method of service life and life cycle maintenance strategies. Regarding the former, a reliability function of structural safety performance is used, based on the hazard rate or hazard function of a deterioration RC building during a rare earthquake. For repair selection, probabilistic effect assessment models for considering the recurrence of deterioration in repaired areas and the deterioration proceeding in unrepaired areas were developed. In this manner, the system can be used to determine the optimal life cycle maintenance strategy. Furthermore, the developed system was tested in a case study for five types of repair works containing (i) finishing renewal, (ii) patch repair, (iii) chloride removal, and (iv) steel supplementation. The results revealed that maintenance strategies that include steel supplementation are effective in reducing the life cycle cost of RC buildings located in regions with a high hazard of chloride ingress and seismic activity.
Furthermore, new approaches like the renewal-theory-based life cycle analysis (RTLCA) are developed. Kumar and Gardoni [48] propose such a model and describe it as a novel probabilistic formulation for the life-cycle analysis of deteriorating systems. The formulation includes equations to obtain important life cycle variables like the expected time lost in repairs, the reliability of the system, and the cost of operation and failure. RTLCA minimizes the need for computationally expensive simulations and offers analytical equations to estimate the life cycle performance measures for a system. The model is tested for the life cycle analysis of a RC bridge where the structure is repaired whenever the instantaneous probability of failure exceeds an acceptable limit. The study shows the importance of frequent repairs in the case of a long-term service life. However, for a short service life, frequent repairs could be disadvantageous.
Lastly, Ghodoosi et al. [57] developed a method as a new procedure to predict the most proper intervention strategy for bridges where the structural reliability was maintained with the minimum life cycle intervention cost. The innovative combination of reliability analysis at the system level, nonlinear finite-element modeling, and genetic algorithm (GA)-based life cycle-cost optimization meant to assist decision-makers in planning bridge maintenance and rehabilitation in a more practical manner including safety and budget limitations criteria. The optimization results proved that the application of minor intervention activities significantly reduces the life cycle cost when compared with the conventional case in which no preventive measure is implemented. However, the entailed minimum cost of implementing only minor intervention activities might be significantly higher when compared with a case in which a combination of essential and preventive measures is applied. There exist various intervention methods in which each may entail different costs and bridge life cycles. For instance, the innovative application of FRP laminates for strengthening the reinforced concrete deck may result in higher costs and a longer bridge life cycle as compared with conventional techniques, an issue of concern for future work in this context.
To conclude, it is shown that assuming an appropriate life span is extremely important in order to achieve reliable results. Several studies are available predicting the service life through prediction methods and models. However, these approaches are often a simplification of reality and are not always reliable. Furthermore, many different approaches are present. To obtain a better overview, a more comprehensive and detailed literature review should be performed on this subject. In addition, Qu et al. [16] also stated that more research is needed about a comprehensive forecast of conveying and degradation mechanisms in both cracked and uncracked concrete. Frangopol and Soliman [60] also mentioned that methodologies for processing the large amount of data for damage diagnosis and prognosis in existing structures are still required. Lastly, Taffese and Sistonen [74] also stated that performing more research on the service life prediction of repaired concrete structures using advanced modeling techniques is necessary.

2.4. End-of-Life Characteristics

End-of-Life Galvanic Sacrificial Anodes

In order to prevent or stop the reinforcement corrosion of RCS, CP can be applied. One method that can be used is the use of galvanic sacrificial anodes (mostly of zinc) that are connected to the rebars. The anodes consist of a more active or less noble metal compared to the reinforcement by which the sacrificial anodes will corrode instead of the rebars connected with it. When the anodes are placed in the concrete structure, they are embedded in mortar that intercepts the reaction products of the corrosion reaction (zinc oxide). In the end-of-life phase of the concrete structure, they are crushed and often reused together with the concrete rubble. However, the effect of galvanic sacrificial anodes on the environmental impact is still unclear [14]. If the reclaimed concrete aggregates are used in road foundations, the zinc corrosion products could leach into the groundwater system. However, it is unclear if and to what extent this leaching will happen in reality. Some general research has been done about this subject but not specifically about the leaching behavior of reclaimed concrete with residual fractions of zinc oxide.
According to de la Fuente et al. [75], the formation of corrosion products in an atmospheric environment is a complex and continuously changing process. The degree of complexity and the rate of change depend on the type of atmosphere and the various factors involved. According to Thomas et al. [76], corrosion chiefly occurs in alkaline conditions by the formation of zinc hydroxide complexes or zinc oxides that could protect the surface depending on local pH and potential at the metal surface. Zinc forms immediately a fine film of zincite (ZnO) when it is exposed to any environment [77][78]. However, when water is present, this film is promptly transformed into zinc hydroxide (Zn(OH)2). These products are found in an atmospheric environment, so if all of these or even more could be formed by a sacrificial anode (alkaline environment) is still unclear. According to Vera et al. [77], the most important insoluble zinc corrosion products, besides ZnO, in a marine environment are simonkolleite (Zn5(OH)8Cl2·H2O), hydrozincite (Zn5(CO3)2(OH)6), and zinc and sodium hydroxyl-chlorosulfate (NaZn4Cl(OH)6SO4·6H2O).
These corrosion products include soluble products such as zinc chloride (ZnCl2) and zinc sulfate (ZnSO4), which can leach by rainfall and can be detected in subsequent runoff solutions. The research of Santana et al. [79] investigated the atmospheric corrosion of zinc samples exposed at 25 test sites with different climatic and pollution conditions during a two-year exposure program. The composition and distribution of the corrosion products of zinc were analyzed qualitatively by X-ray diffraction (XRD). They also found that simonkolleite (Zn5(OH)8Cl2) and hydrozincite (Zn4CO3(OH)6·H2O) are the most frequently observed corrosion products. However, in smaller amounts are zinc oxysulfate (Zn3O(SO4)2), zinc hydroxysulfate (Zn4SO4(OH)6), zinc diamminehydroxynitrate (Zn5(OH)8(NO3)2·2NH3), and zinc chlorohydroxysulfate (NaZn4Cl(OH)6SO4·6H2O). An example of an occurring corrosion reaction at the galvanic anode can be seen in Equations (1)–(3). Zinc reacts with both acids and bases to form salt [80]. According to Kamde et al. [80], the rate of the corrosion of zinc is high at a pH less than 6 (acidic) and greater than 12.5 (basic).
Zn → Zn2+ + 2e−  (1)
Zn2+ + 4OH− →Zn(OH)42- (2)
Zn(OH)42− → ZnO + 2OH− + H2O (3)
An advantage of highly alkaline encapsulating mortar (pH > 14) is that the zinc corrosion products exist as soluble zincate ions (Zn(OH)42−). They move into the pores of the encapsulating mortar due to their solubility where they precipitate out as zinc oxide once supersaturation occurs. On the other hand, a layer of white zinc corrosion products (zinc oxides/hydroxides) will surround the unreacted zinc metal. Dugarte and Sagües [81] indicated that the anodes stop functioning due to encapsulating mortar failing to provide an adequate environment for continuous corrosion after about a quarter of the galvanic metal is consumed.
The study of Diotti et al. [82] investigated the leaching behavior of construction and demolition wastes and recycled aggregates. They found that the leaching of zinc is not critical, but this is obviously not related to (only) aggregates from concrete with sacrificial anodes. Besides, the influence of grain size and volumetric reduction on the release of contaminants was also investigated. Material crushing leads to higher pollutant release due to the increase of the contact surfaces between recycled concrete aggregates (RCA) and leaching agents. At the same time, sieving operations can also lead to greater fine fractions that cause high releases. However, the difference is only limited. Several studies identified the high releases of Zn at neutral or alkaline pH values [83][84][85][86]. Besides, high releases of Zn (metal cations) were also detected at lower pH values [85]. Therefore, Zn is highly released in both acidic and alkaline environments.
The study of Vera et al. [77] also investigated the precipitation runoff from zinc in a marine environment to define the pH valu, and the Cl–, SO42–, and Zn2+ ion concentrations. The pH values for the runoff solutions are similar to those for the rainwater samples and vary between pH 6.1 and 7.1. The amount of chloride ion and sulfate concentration in the runoff is dependent on the location (atmospheric chloride and SO2). The zinc concentrations that were measured monthly for the runoff solutions are well-correlated with the amount of rainfall, the rainfall periodicity, and the duration of the dry periods between rainfall events. So, to conclude, the different corrosion products and the amount of it leaching by rainfall is highly dependent on the environment and the rainfall characteristics. According to several studies of Kukurugya et al. [87][88][89] wherein the leaching behavior of furnace sludge/dust was investigated, the leaching of zinc is dependent on the concentration of the fluid (here acid), temperature, and leaching time. According to the study of Kara De Maeijer et al. [90], wherein the leaching behavior of a crumb rubber in concrete was investigated, cementitious materials can well confine trace metals such as zinc. However, some leaching is still possible.
The previous section shows nicely that the leaching behavior of galvanic anodes is an important point of attention. Based on the mentioned studies and the absence of the information about the corrosion products of sacrificial anodes and the leaching behavior of concrete aggregates containing it, it can be concluded that further research is needed. Besides the amount of leaching, the form in which it leaches out is also important, a stable non-toxic form is namely less bad than a heavy carcinogenic form. Therefore, leaching tests with concrete containing used sacrificial anode parts (alkaline environment) based on the Belgium environment and rainfall would be of high value.

References

  1. Whiteley, D.; Goethert, K.; Goodwin, F.; Golter, H.; Kennedy, J.; Wattenburg Komas, T.; Meyer, J.; Petree, M.; Smith, B.; Trepanier, S. Sustainability for Repairing and Maintaining Concrete and Masonry Buildings; ICRI Committee: Rosemont, IL, USA, 2014; Available online: https://cdn.ymaws.com/www.icri.org/resource/collection/1023A08D-21D0-4AE9-8F9A-5C0A111D4AC9/ICRICommittee160-Sustainability_whitepaper.pdf (accessed on 19 January 2022).
  2. Confederation of Construction. 2013–2014 Annual Report: Construction and Europe , 2014. Available online: https://www.constructionconfederation.be/Portals/0/Documents/Jaarverslagen/Jaarverslag-2013-2014-Confederatie-Bouw.pdf?ver=2017-09-15-161342-943 (accessed on 19 January 2022).
  3. De Schepper, M.; Van den Heede, P.; Van Driessche, I.; De Belie, N. Life cycle assessment of completely recyclable concrete. Materials 2014, 7, 6010–6027.
  4. Behera, M.; Bhattacharyya, S.; Minocha, A.; Deoliya, R.; Maiti, S. Recycled aggregate from C&D waste & its use in concrete–A breakthrough towards sustainability in construction sector: A review. Constr. Build. Mater. 2014, 68, 501–516.
  5. Ali, M.B.; Saidur, R.; Hossain, M.S. A review on emission analysis in cement industries. Renew. Sust. Energ. Rev. 2011, 15, 2252–2261.
  6. Xi, F.; Davis, S.J.; Ciais, P.; Crawford-Brown, D.; Guan, D.; Pade, C.; Shi, T.; Syddall, M.; Lv, J.; Ji, L.; et al. Substantial global carbon uptake by cement carbonation. Nat. Geosci. 2016, 9, 880–883.
  7. European Commission. Circular economy—Overview. Available online: https://ec.europa.eu/eurostat/web/circular-economy (accessed on 23 November 2021).
  8. Part 9: General principles for the use of products and systems. In NBN EN 1504-9: Products and Systems for the Protection and Repair of Concrete Structures—Definitions, Requirements, Quality Control and Evaluation of Conformity; European Committee for Standardization: Brussels, Belgium, 2008.
  9. Jones, A.E.K.; Marsh, B.K.; Clark, L.A.; Seymour, B.P.A.M.; Long, A.M. Development of a holistic approach to ensure cement, the durability of new concrete construction. BCA Research Report, C/21. Br. Cem. Assoc. 1997, 81.
  10. Wittocx, L.; Craeye, B.; Audenaert, A.; Buyle, M.; Caspeele, R.; Gruyaert, E.; Minne, P.; Dooms, B. Vademecum der Gebreken: Uitkragende Betonnen Balkons . Balcon-E Odisee. 2021. Available online: https://balcon-e.odisee.be/sites/default/files/public/2021-09/Balcon-e%20Vademecum%20der%20gebreken_0.pdf (accessed on 19 January 2022).
  11. Popov, B.N. Chapter 7—Pitting and Crevice Corrosion. In Corrosion Engineering; Popov, B.N., Ed.; Elsevier: Amsterdam, The Netherlands, 2015; pp. 289–325.
  12. Ferreira, J.; Duarte Pinheiro, M.; de Brito, J. Economic and environmental savings of structural buildings refurbishment with demolition and reconstruction—A Portuguese benchmarking. J. Build. Eng. 2015, 3, 114–126.
  13. Gaspar, P.L.; Santos, A.L. Embodied energy on refurbishment vs. demolition: A southern Europe case study. Energy Build. 2015, 87, 386–394.
  14. Wittocx, L.; Buyle, M.; Audenaert, A.; Seuntjens, O.; Renne, N.; Craeye, B. Revamping corrosion damaged reinforced concrete balconies: Life cycle assessment and life cycle cost of life-extending repair methods. J. Build. Eng. 2022, 52, 24.
  15. Polder, R.B.; Peelen, W.H.A. 25 years of experience with cathodic protection of steel in concrete in the Netherlands. In Durability of Reinforced Concrete from Composition to Protection: Selected Papers of the 6th International RILEM PhD Workshop Held in Delft, The Netherlands, July 4–5, 2013; Andrade, C., Gulikers, J., Polder, R., Eds.; Springer International Publishing: Cham, Switzerland, 2015; pp. 69–75.
  16. Qu, F.; Li, W.; Dong, W.; Tam, V.W.Y.; Yu, T. Durability deterioration of concrete under marine environment from material to structure: A critical review. J. Build. Eng. 2021, 35, 102074.
  17. Polder, R.B. Cathodic protection of reinforced concrete structures in the Netherlands—Experience and developments. Heron 1998, 43, 3–14.
  18. Bertolini, L.; Bolzoni, F.; Pedeferri, P.; Lazzari, L.; Pastore, T. Cathodic protection and cathodic preventionin concrete: Principles and applications. J. Appl. Electrochem. 1998, 28, 1321–1331.
  19. Ribeiro, I.; Peças, P.; Silva, A.; Henriques, E. Life cycle engineering methodology applied to material selection, a fender case study. J. Clean Prod. 2008, 16, 1887–1899.
  20. Wang, J.H. 23–Lifecycle cost and performance analysis for repair of concrete tunnels. In Eco-Efficient Repair and Rehabilitation of Concrete Infrastructures; Pacheco-Torgal, F., Melchers, R.E., Shi, X., Belie, N.D., Tittelboom, K.V., Sáez, A., Eds.; Woodhead Publishing: Sawston, UK, 2018; pp. 637–672.
  21. ISO 14040:2006; Environmental Management-Life Cycle Assessment-Principles and Frameworks. International Organisation for Standardization: Geneva, Switzerland, 2006.
  22. Moins, B.; France, C.; Van den bergh, W.; Audenaert, A. Implementing life cycle cost analysis in road engineering: A critical review on methodological framework choices. Renew. Sust. Energ. Rev. 2020, 133, 110284.
  23. Life Cycle Cost Analysis Primer; U.S. Department of Transportation: Washington, DC, USA, 2002.
  24. Matos, J.; Solgaard, A.; Linneberg, P.; Sanchez Silva, M.; Strauss, A.; Stipanovic, I.; Casas, J.; Masovic, S.; Caprani, C.; Novak, D. Life cycle cost management of concrete structures. In Proceedings of the IABSE Conference—Engineering the Past, to Meet the Needs of the Future, Copenhagen, Denmark, 25–28 June 2018; pp. 25–27.
  25. Hájek, P.; Fiala, C.; Kynčlová, M. Life cycle assessments of concrete structures—A step towards environmental savings. Struct. Concr. 2011, 12, 13–22.
  26. Vieira, D.R.; Calmon, J.L.; Coelho, F.Z. Life cycle assessment (LCA) applied to the manufacturing of common and ecological concrete: A review. Constr. Build. Mater. 2016, 124, 656–666.
  27. Andrade, C.; Izquierdo, D. Benchmarking through an algorithm of repair methods of reinforcement corrosion: The repair index method. Cem. Concr. Compos. 2005, 27, 727–733.
  28. Carlsson Reich, M. Economic assessment of municipal waste management systems—case studies using a combination of life cycle assessment (LCA) and life cycle costing (LCC). J. Clean Prod. 2005, 13, 253–263.
  29. Hoogmartens, R.; Van Passel, S.; Van Acker, K.; Dubois, M. Bridging the gap between LCA, LCC and CBA as sustainability assessment tools. Environ. Impact Assess. Rev. 2014, 48, 27–33.
  30. Miah, J.H.; Koh, S.C.L.; Stone, D. A hybridised framework combining integrated methods for environmental Life Cycle Assessment and Life Cycle Costing. J. Clean Prod. 2017, 168, 846–866.
  31. Buyle, M.; Braet, J.; Audenaert, A. Life cycle assessment in the construction sector: A review. Renew. Sust. Energ. Rev. 2013, 26, 379–388.
  32. Janjua, S.Y.; Sarker, P.K.; Biswas, W.K. Impact of service life on the environmental performance of buildings. Buildings 2019, 9, 9.
  33. Morales, M.F.D.; Passuello, A.; Kirchheim, A.P.; Ries, R.J. Monte Carlo parameters in modeling service life: Influence on life cycle assessment. J. Build. Eng. 2021, 44, 103232.
  34. Grant, A.; Ries, R. Impact of building service life models on life cycle assessment. Build. Res. Inf. 2013, 41, 168–186.
  35. Val, D.; Chernin, L. Service life performance of reinforced concrete structures in corrosive environments. In Life Cycle Civil Engineering; CRC Press: Boca Raton, FL, USA, 2008; pp. 267–272.
  36. Palacios-Munoz, B.; Peuportier, B.; Gracia-Villa, L.; López-Mesa, B. Sustainability assessment of refurbishment vs. new constructions by means of LCA and durability-based estimations of buildings lifespans: A new approach. Build. Environ. 2019, 160, 10.
  37. Vilches, A.; Garcia-Martinez, A.; Sanchez-Montañes, B. Life cycle assessment (LCA) of building refurbishment: A literature review. Energy Build. 2017, 135, 286–301.
  38. Turk, J.; Cotič, Z.; Mladenovič, A.; Šajna, A. Environmental evaluation of green concretes versus conventional concrete by means of LCA. Waste Manag. 2015, 45, 194–205.
  39. Van den Heede, P.; De Belie, N. Environmental impact and life cycle assessment (LCA) of traditional and ‘green’ concretes: Literature review and theoretical calculations. Cem. Concr. Compos. 2012, 34, 431–442.
  40. Rohden, A.B.; Garcez, M.R. Increasing the sustainability potential of a reinforced concrete building through design strategies: Case study. Case Stud. Constr. Mater. 2018, 9, e00174.
  41. Ahmed, I.M.; Tsavdaridis, K.D. Life cycle assessment (LCA) and cost (LCC) studies of lightweight composite flooring systems. J. Build. Eng. 2018, 20, 624–633.
  42. Eurostat. Glossary: Country Codes. Available online: https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Glossary:Country_codes (accessed on 8 July 2022).
  43. Scope, C.; Vogel, M.; Guenther, E. Greener, cheaper, or more sustainable: Reviewing sustainability assessments of maintenance strategies of concrete structures. Sustain. Prod. Consum. 2021, 26, 838–858.
  44. Farahani, A. Life Cycle Cost GA optimization of repaired reinforced concrete structures located in a marine environment. SCCE 2019, 3, 41–50.
  45. Polder, R.B.; Leegwater, G.; Worm, D.; Courage, W. Service life and life cycle cost modelling of cathodic protection systems for concrete structures. Cem. Concr. Compos. 2014, 47, 69–74.
  46. Krishnan, N.; Kamde, D.K.; Veedu, Z.D.; Pillai, R.G.; Shah, D.; Velayudham, R. Long-term performance and life cycle cost benefits of cathodic protection of concrete structures using galvanic anodes. J. Build. Eng. 2021, 42, 102467.
  47. Lee, H.; Lee, H.-S.; Suraneni, P.; Singh, J.K.; Mandal, S. Prediction of service life and evaluation of probabilistic Life cycle Cost for surface-repaired carbonated concrete. J. Mater. Civ. Eng. 2020, 32, 04020297.
  48. Kumar, R.; Gardoni, P. Renewal theory-based life cycle analysis of deteriorating engineering systems. Struct. Saf. 2014, 50, 94–102.
  49. Lepech, M.D.; Geiker, M.; Stang, H. Probabilistic design and management of environmentally sustainable repair and rehabilitation of reinforced concrete structures. Cem. Concr. Compos. 2014, 47, 19–31.
  50. Årskog, V.; Fossdal, S.; Gjørv, O. Life cycle assessment of repair and maintenance systems for concrete structures. In Proceedings of the Int. Workshop on Sustainable Development and Concrete Technology, Beijing, China, 20–21 May 2004; pp. 193–200.
  51. Chiu, C.-K.; Noguchi, T.; Kanematsu, M. Effects of maintenance strategies on the life cycle performance and cost of a deteriorating RC building with high-seismic hazard. J. Adv. Concr. Technol. 2010, 8, 157–170.
  52. Xie, H.-B.; Wu, W.-J.; Wang, Y.-F. Life-time reliability based optimization of bridge maintenance strategy considering LCA and LCC. J. Clean Prod. 2018, 176, 36–45.
  53. Navarro, I.J.; Martí, J.V.; Yepes, V. Reliability-based maintenance optimization of corrosion preventive designs under a life cycle perspective. Environ. Impact Assess. Rev. 2019, 74, 23–34.
  54. Cadenazzi, T.; Lee, H.; Suraneni, P.; Nolan, S.; Nanni, A. Evaluation of probabilistic and deterministic life cycle cost analyses for concrete bridges exposed to chlorides. Clean Eng. Tech. 2021, 4, 100247.
  55. Shen, L.; Soliman, M.; Ahmed, S.A. A probabilistic framework for life cycle cost analysis of bridge decks constructed with different reinforcement alternatives. Eng. Struct. 2021, 245, 112879.
  56. Safi, M.; Sundquist, H.; Karoumi, R. Cost-efficient procurement of bridge infrastructures by incorporating life cycle cost analysis with bridge management systems. J. Bridge Eng. 2015, 20, 04014083.
  57. Ghodoosi, F.; Abu-Samra, S.; Zeynalian, M.; Zayed, T. Maintenance cost optimization for bridge structures using system reliability analysis and genetic algorithms. J. Constr. Eng. Manag. 2018, 144, 04017116.
  58. Polder, R.; Pan, Y.; Courage, W.; Peelen, W.H. Preliminary study of life cycle cost of preventive measures and repair options for corrosion in concrete infrastructure corrosion in concrete infrastructure. Heron 2016, 61, 1–13.
  59. Islam, S.; Kishi, T. Effects of cover properties and repair methods on LCC estimation of reinforced concrete structure. Internet J. Soc. Soc. Manag. Syst. 2010, 6, 1–8.
  60. Frangopol, D.M.; Soliman, M. Life cycle of structural systems: Recent achievements and future directions. Struct. Infrastruct. Eng. 2016, 12, 1–20.
  61. Van den Heede, P.; De Belie, N.; Pittau, F.; Habert, G.; Mignon, A. Life cycle assessment of Self-Healing Engineered Cementitious Composite (SH-ECC) used for the rehabilitation of bridges. In Proceedings of the 6th International Symposium on Life cycle Civil Engineering (IALCCE), Ghent, Belgium, 28–31 October 2018; pp. 2269–2275.
  62. Habert, G.; Denarié, E.; Šajna, A.; Rossi, P. Lowering the global warming impact of bridge rehabilitations by using Ultra High Performance Fibre Reinforced Concretes. Cem. Concr. Compos. 2013, 38, 1–11.
  63. Hajiesmaeili, A.; Pittau, F.; Denarié, E.; Habert, G. Life Cycle Analysis of strengthening existing RC structures with R-PE-UHPFRC. Sustainability 2019, 11, 6923.
  64. Navarro, I.J.; Yepes, V.; Martí, J.V.; González-Vidosa, F. Life cycle impact assessment of corrosion preventive designs applied to prestressed concrete bridge decks. J. Clean Prod. 2018, 196, 698–713.
  65. Zirps, M.; Lepech, M.; Savage, S.; Michel, A.; Stang, H.; Geiker, M. Probabilistic design of sustainable reinforced concrete infrastructure repairs using sipmath. Front. Built Environ. 2020, 6, 72.
  66. Lepech, M.; Geiker, M.R.; Stang, H. Probabilistic design framework for sustainable repair and rehabilitation of civil infrastructure. In Proceedings of the Fib Symposium 2011, Prague, Czech Republic, 8–10 June 2011; pp. 1029–1032.
  67. Choi, K.; Lee, H.W.; Mao, Z.; Lavy, S.; Ryoo, B.Y. Environmental, economic, and social implications of highway concrete rehabilitation alternatives. J. Constr. Eng. Manag. 2016, 142, 04015079.
  68. Wang, H. 25—Life cycle analysis of repair of concrete pavements. In Eco-Efficient Repair and Rehabilitation of Concrete Infrastructures; Pacheco-Torgal, F., Melchers, R.E., Shi, X., Belie, N.D., Tittelboom, K.V., Sáez, A., Eds.; Woodhead Publishing: Sawston, UK, 2018; pp. 723–738.
  69. Menna Barreto, M.F.F.; Timm, J.F.G.; Passuello, A.; Dal Molin, D.C.C.; Masuero, J.R. Life cycle costs and impacts of massive slabs with varying concrete cover. Clean Eng. Tech. 2021, 5, 100256.
  70. Binder, F. Life cycle costs of selected concrete repair methods demonstrated on chloride contaminated columns. In Proceedings of the 11th International Probabilistic Workshop, Brno, Czech Republic, 6–8 November 2013.
  71. Palacios-Munoz, B.; Gracia-Villa, L.; Zabalza-Bribián, I.; López-Mesa, B. Simplified structural design and LCA of reinforced concrete beams strengthening techniques. Eng. Struct. 2018, 174, 418–432.
  72. Walraven, J.; van der Horst, A. FIB Model Code for Concrete Structures 2010; Internation Federation for Structural Concrete (fib): Lausanne, Switzerland, 2013.
  73. Monteiro, A.V.; Gonçalves, A. Probabilistic assessment of the depassivation limit state of reinforced concrete structures based on inspection results. J. Build. Eng. 2022, 49, 104063.
  74. Taffesea, W.Z.; Sistonen, E. Service Life Prediction of Repaired Structures Using Concrete Recasting Method: State-of-the-Art. Procedia Eng. 2013, 57, 1138–1144.
  75. De la Fuente, D.; Castano, J.; Morcillo, M. Long-term atmospheric corrosion of zinc. Corros. Sci. 2007, 49, 1420–1436.
  76. Thomas, S.; Birbilis, N.; Venkatraman, M.; Cole, I. Corrosion of zinc as a function of pH. Corrosion 2012, 68, 015009-1–015009-9.
  77. Vera, R.; Guerrero, F.; Delgado, D.; Araya, R. Atmospheric corrosion of galvanized steel and precipitation runoff from zinc in a marine environment. J. Braz. Chem. Soc. 2013, 24, 449–458.
  78. Appendix, J. The atmospheric corrosion chemistry of zinc. In Atmospheric Corrosion; Leygraf, C., Odnevall Wallinder, I., Tidblad, J., Graedel, T., Eds.; Wiley: New York, NY, USA, 2016; pp. 348–359.
  79. Santana, J.; Fernández-Pérez, B.; Morales, J.; Vasconcelos, H.; Souto, R.; González, S. Characterization of the corrosion products formed on zinc in archipelagic subtropical environments. Int. J. Electrochem. Sci. 2012, 7, 12730–12741. Available online: http://www.electrochemsci.org/papers/vol12737/71212730.pdf (accessed on 10 July 2022).
  80. Kamde, D.K.; Manickam, K.; Pillai, R.G.; Sergi, G. Long-term performance of galvanic anodes for the protection of steel reinforced concrete structures. J. Build. Eng. 2021, 42, 103049.
  81. Sagues, A.A.; Dugarte, M. Galvanic Point Anodes for Extending the Service Life of Patched Areas upon Reinforced Concrete Bridge Members. Report BD544-09, University of South Florida, USA, 2009. Available online: https://rosap.ntl.bts.gov/view/dot/16963 (accessed on 19 January 2022).
  82. Diotti, A.; Plizzari, G.; Sorlini, S. Leaching behaviour of construction and demolition wastes and recycled aggregates: Statistical analysis applied to the release of contaminants. Appl. Sci. 2021, 11, 6265.
  83. Del Rey, I.; Ayuso, J.; Galvín, A.; Jiménez, J.R.; López, M.; García-Garrido, M. Analysis of chromium and sulphate origins in construction recycled materials based on leaching test results. Waste Manag. 2015, 46, 278–286.
  84. Galvín, A.P.; Ayuso, J.; García, I.; Jiménez, J.R.; Gutiérrez, F. The effect of compaction on the leaching and pollutant emission time of recycled aggregates from construction and demolition waste. J. Clean Prod. 2014, 83, 294–304.
  85. Nurhanim, A.; Norli, I.; Morad, N.; Khalil, H. Leaching behavior of construction and demolition waste (concrete and gypsum). IJEE 2016, 7, 203–211.
  86. Chen, J.; Tinjum, J.M.; Edil, T.B. Leaching of alkaline substances and heavy metals from recycled concrete aggregate used as unbound base course. TRR 2013, 2349, 81–90.
  87. Trung, Z.H.; Kukurugya, F.; Takacova, Z.; Orac, D.; Laubertova, M.; Miskufova, A.; Havlik, T. Acidic leaching both of zinc and iron from basic oxygen furnace sludge. J. Hazard. Mater. 2011, 192, 1100–1107.
  88. Havlik, T.; Kukurugya, F.; Orac, D.; Parilak, L. Acidic leaching of EAF steelmaking dust. World Metall. ERZMETALL 2012, 65, 48–56.
  89. Havlik, T.; Kukurugya, F.; Orac, D.; Vindt, T.; Miskufova, A.; Takacova, Z. Leaching of zinc and iron from blast furnace dust in sulphuric acid solutions. Metall 2012, 66, 267–270.
  90. Kara De Maeijer, P.; Craeye, B.; Blom, J.; Bervoets, L. Crumb rubber in concrete—the barriers for application in the construction industry. Infrastructures 2021, 6, 116.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
Upload a video for this entry
Information
Subjects: Construction & Building Technology
Contributors MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :
Neel Renne
,
Patricia Kara De Maeijer
,
Bart Craeye
,
Matthias Buyle
,
Amaryllis Audenaert
View Times: 700
Entry Collection: Environmental Sciences
Revisions: 6 times (View History)
Update Date: 21 Oct 2022
Table of Contents
    1000/1000
    Hot Most Recent
    Video Production Service
    Feedback