Abstract
Civil engineering failures currently amount to 5 to 10 % of the total investment in new buildings and structures. These failures not only represent important cost considerations, they also have an environmental burden associated with them. Structures often deteriorate because not enough attention is given during the design stage and most standards for structural design do not cover design for service life. Designing for durability is often left to the structural designer or architect who may not have the necessary skills, and the result is all too often failure, incurring high maintenance and repair costs. Knowledge of the long-term behaviour of materials, building components and structures is the basis for avoiding these failures. Durability of engineering structures uses on the design of buildings for service life, effective maintenance and repair techniques in order to reduce the likelihood of failure. It describes the in situ performance of all the major man-made materials used in civil engineering construction - metals (steel and aluminium), concrete and wood. In addition some relatively new high-performance materials are discussed - high-performance concrete, high-performance steel and fibre-reinforced polymers (FRP). Deterioration mechanisms and the measures to counteract these, as well as subsequent maintenance and repair techniques are also considered and the latest standards on durability and repair are explained. Strategies for durability, maintenance and repair, including life cycle costing and environmental life cycle assessment methods are discussed. Finally practical case studies show how repairs can be made and the best ways of ensuring long term durability. This book is aimed at students in civil engineering, engineers, architects, contractors, plant managers, maintenance managers and inspection engineers. • Explains the reasons why structures often deteriorate before they should because of poor design • Shows how to design structures effectively for service life • Considers durability characteristics of standard and high performance construction materials.
... Issues like maintenance of structures, sustainability in design, corrosion effects, repair techniques and building waste management are an important field of research and practice among the engineering community. While the knowledge on durability design for a specified service life without unexpected maintenance and repair was available, it was often not applied by designers or contractors (Bijen, 2003). Neither durability design nor corrosion prevention were given the appropriate priority, fact that can be easily noticed while observing the existing structured environment of the past decades, especially in urban or marine and coastal regions. ...
... In the case of damage that was not predicted in the designed service life, the performance of a building material, a building element or a structure IJSI is seriously affected. As illustrated in Figure 1 (Bijen, 2003), curve a presents the designed performance in time. Curve b describes the performance versus time when the maintenance required to keep performance above the critical level has not been predicted, with the result that damage has occurred. ...
... The variables S and R can be any quantities and expressed in any units. The required durability performance in a particular environment depends on the required service life over a specified time, on the possible future use of the structure, on the planned maintenance in service and on the consequences of failure that may refer to the decrease of the (b) performance of limited-quality construction over time, corrective maintenance was necessary (Bijen, 2003) Contemporary architectural technology ...
Purpose
This study aims to discuss the causes of short-lived structuring of contemporary buildings. The life expectancy of structures may be theoretically predefined during the state of the design. This time period, known as the service life of structures, is determined by the load or the deformation level at which irreversible failures of the bearing structure may occur. On the other hand, planned obsolescence and perceived obsolescence, observed in the western world since the first half of 20th century, are currently setting an economic reality and are part of an expanded framework that, apart from architectural structures, extends to all design fields. The effects of short-lived structuring on environmental and energy terms are presented and theoretical and experimental recommendations from the literature are cited, as well as recommendations that have already been successfully applied in some countries.
Design/methodology/approach
This study aims to discuss the issues associated with short-lived structuring, durability and obsolescence of contemporary structures. For this purpose, theoretical and experimental recommendations from the literature are cited, via an extensive state of the art research.
Findings
Short-lived structuring has been a field of research during recent years. Terms such as durability are being introduced into Design Codes, while trends like perceived obsolescence and environmental impact raise issues for research. Moreover, the results of short-lived structuring are becoming more and more apparent, indicating an unsustainable reality. Issues like maintenance of structures, sustainability in design, corrosion effects, repair techniques and building waste management are an important field of research among the engineering community. In this study, the parameters affecting the lifespan of contemporary structures have been discussed.
Originality/value
The effects of short-lived structuring on environmental and energy terms are presented and theoretical and experimental recommendations from the literature are cited. The parameters studied herein concern material properties and design approach but also environmental and energy-related ones.
... The durability of wood depends largely on the environment surrounding it. Under the right conditions, wood service life has been known to exceed 500 years (Bijen, 2003). ...
... For one strain of soft-rot fungus the bamboo species were grouped into class II and class III (moderately durable), for another strain of white-rot the bamboo species were grouped into class II, class III, and class IV (little durable). Fungi require at least a water content of 22% to rot wood (Bijen, 2003). It is not known how low the moisture content needs to be to protect bamboo against fungi. ...
... Protective finishes and coatings can improve bamboo durability against fungi by protecting it from moisture (Bijen, 2003). Heat treatment is another option for treatment against biological decay. ...
The behaviour of bamboo reinforced concrete is not well understood and the methods proposed for its design suffers from problems that can result in an overly conservative design in some situations and unconservative designs in others. This investigation was carried using a combination of experimental testing and finite element modelling. It included flexural testing of bamboo reinforced beams and pull-out testing of bamboo splints. This research contributes to a limit state design method for bamboo reinforced concrete. It includes modelling bond, deflection, and cracking and it investigates how to model the flexural and shear capacities of bamboo reinforced concrete. In addition, this research investigates the credentials of bamboo as a low carbon footprint reinforcement of concrete. Corrugation is presented as a solution for the bamboo weak bond with concrete. A model is developed that can estimate the bond of corrugated bamboo at short embedment lengths based on the shear strength of bamboo and the shear-friction of concrete. A model is developed that can estimate the bond of bamboo at any embedment length using the modulus of elasticity and reinforcement area as inputs. A deflection model is presented that takes into account the effect of low modulus of elasticity of bamboo reinforcement and its weaker bond with concrete in comparison with steel. The cracking of bamboo reinforced concrete is analysed and the results are used to validate established cracking models. Equivalent serviceability to up to 1% steel-reinforced concrete can be achieved using corrugated bundled bamboo reinforcement. At higher reinforcement percentage the use of bamboo becomes less practical due to the limitation of section workability.
... The durability of wood depends largely on the environment surrounding it. Under the right conditions, wood service life has been known to exceed 500 years [17]. The biological decay of wood can be caused by fungi, insects, marine borers and bacteria [18]. ...
... Fungi require oxygen, moisture and appropriate temperatures. All of these are available for fungi to decay bamboo reinforcement; however, fungi require at least a water content of 22% to decay wood [17]. The use of a waterrepellent treatment can protect against fungi. ...
... To increase the design life of bamboo, it can be treated with preservatives or protective finishes and coatings. Preservatives are restricted to within certain concentrations in a growing number of countries because they are toxic and can contaminate the environment during usage or disposal [17]. Protective finishes and coatings improve bamboo durability by protecting it from moisture. ...
The paper provides a literature review showing (i) the properties of bamboo and
how it lends itself towards its use in reinforced concrete: Bamboo has high tensile strength,
cheap, available in places where steel is not affordable, a renewable resource, and a nonpolluting
material, (ii) the limitations and the issues with using bamboo as reinforcement:
bamboo’s low modulus of elasticity, bamboo’s weak bond with concrete, its durability inside
of concrete, (iii) mechanical properties for different bamboo species: There are about 1200
bamboo species around the world with different mechanical properties, as a reinforcing
material, species with high tensile strength and high modulus of elasticity are desirable. There
are some data on the mechanical properties of few species in literature, the results vary
significantly for the same species between different researchers, and this can be attributed to
two reasons as follows: different testing methods and different properties of bamboo culms
used by different researchers, (iv) bamboo’s high tensile strength encouraged many researchers
to study its use as bending reinforcement. The results found by the different researchers varied
significantly, but generally lower than expected from using a material with bamboo tensile
strength. The researchers have presented the experimental bending strength at failure. However
what the researchers presented does not inform if the bamboo reinforcement tensile strength
has been fully utilised, and does not inform how the beams compare to steel reinforced beams.
This paper compares the bending capacity of bamboo reinforced beams to the theoretical
bending capacity of steel reinforced beams and shows that the tensile strength of bamboo is not
fully utilised when it is used as reinforcement.
... Material quality is fundamental to ensuring that structures are safe, durable, and highperforming (Ramchandra and Gehlot, 2012;Allen and Iano, 2019). High-quality materials guarantee not only the robustness and longevity of constructions but also affect long-term maintenance and repair costs (Bijen, 2003). Conversely, defective or non-compliant materials can lead to severe failures, high repair costs, and safety hazards (Higham, Challender and Watts, 2022). ...
... The 2018 Genoa Bridge collapse is a case where material quality issues and inadequate maintenance led to a failure. Corrosion problems in steel bridges, often due to insufficient protection or poor-quality steel, and material failures in residential buildings caused by manufacturing defects illustrate the serious consequences of quality issues (Bijen, 2003;Ahzahar et al., 2011). ...
Construction materials are crucial for the safety and longevity of structures, as they must withstand environmental conditions and be durable. Adherence to stringent standards and regulations is essential for materials like concrete, steel, wood, bricks, and composites. Common defects include manufacturing flaws, storage issues, non-compliance with standards, and variability in quality. To minimize quality problems, rigorous control techniques like material testing, visual inspections, performance testing, and certifications are applied. Proper finishing enhances aesthetics, durability, and performance, while surface preparation, installation, and maintenance are critical for plumbing and electrical systems.
... Pada biaya kapitalisasi, biaya bangunan melibatkan kapitalisasi biaya dimana setiap pengeluaran yang bakal terjadi dimasa depan ditransformasi menjadi nilai yang dapat ditambahkan dalam biaya langsung investasi. Secara umum, kedua pendekatan tersebut menghasilkan kesimpulan yang sama (Bijen, 2003). ...
... Tahap perhitungan biaya pemeliharaan yang diambil pada penelitian ini diadopsi dari (Bijen, 2003).Ketidakpastian pada biaya dan laju bunga yang digunakan diabaikan demi penyederhanaan perhitungan. Komponen biaya pemeliharaan dapat dilihat pada Tabel 1. Selanjutnya ditentukan besarnya biaya yang dibutuhkan untuk empat kondisi desain pelat dak yang berbeda, yaitu: (1). ...
Structural safety is mandatory for a building. It is frequent that this aspect is threatened by the emergence of problems related to structural durability. A review of the performance of structures that meet certain requirements throughout the target service life requires a study of cost optimization. The costs reviewed in practice generally are only investment costs of the construction process without calculating operational and maintenance costs. This research focuses on calculating the life cycle cost for the reinforced concrete slabs due to carbonation. Carbonation estimation is done by measuring hygro-thermal parameters with a digital instrument. Maintenance costs are calculated using a capitalized cost method. The calculation results show that the addition concrete cover thickness is an effective and economical way to prevent the deterioration of concrete slabs due to carbonation.
... Bijen [11] mentioned that the epoxy resins have low resistance to ultraviolet radiation and polyurethanes are sensitive to high-alkalinity environments. Polyurethane is obtained from isocyanates, known worldwide for their tragic association with the Bhopal disaster. ...
... 11 Cost percentage of fly ash geopolymeric mortar ingredients. ...
Premature degradation of ordinary Portland cement (OPC) concrete infrastructure is a current and serious problem with overwhelming costs amounting to several trillion dollars. The use of concrete surface treatments with waterproofing materials to prevent the access of aggressive substances is an important way of enhancing concrete durability. The most common surface treatments use polymeric resins based on epoxy, silicone (siloxane), acrylics, polyurethanes, or polymethacrylate. However, epoxy resins are not cost-efficient and have low resistance to ultraviolet radiation while polyurethanes have low resistance to chemical attack. This chapter presents results of an experimental investigation on the resistance to chemical attack (with sulfuric, hydrochloric, and nitric acid) of several materials: OPC concrete, high-performance concrete, epoxy resin, acrylic painting, and a fly ash-based geopolymeric mortar. Three types of acids with three high concentrations (10%, 20%, and 30%) were used to simulate long-term degradation. A cost analysis was also performed. The results show that the epoxy resin has the best resistance to chemical attack independently of the acid type and the acid concentration. However, the cost analysis shows that the epoxy resin-based solution is the least cost-efficient solution being 70% above the cost efficiency of the fly ash-based geopolymeric mortar.
... Bijen [11] mentioned that the epoxy resins have low resistance to ultraviolet radiation and polyurethanes are sensitive to high-alkalinity environments. Polyurethane is obtained from isocyanates, known worldwide for their tragic association with the Bhopal disaster. ...
... 11 Cost percentage of fly ash geopolymeric mortar ingredients. ...
... Bijen [11] mentioned that the epoxy resins have low resistance to ultraviolet radiation and polyurethanes are sensitive to high-alkalinity environments. Polyurethane is obtained from isocyanates, known worldwide for their tragic association with the Bhopal disaster. ...
... 11 Cost percentage of fly ash geopolymeric mortar ingredients. ...
Infrastructure rehabilitation represents a multitrillion dollar opportunity for the construction industry. In the United States alone, the rehabilitation needs are estimated to exceed 1.6 trillion dollars over the next five years. Since the majority of the existing infrastructure is concrete based, this means that concrete infrastructure rehabilitation is a hot issue. Besides, the sooner concrete deterioration is tackled, the lower are the rehabilitation costs. The majority of current commercial repair materials are not cost efficient and some even present both technical and worrying environmental limitations. This chapter provides a literature overview on concrete repair materials, highlighting current problems faced by them. The potential of alkali-activated mortars to overcome those limitations is analysed.
... Concrete structures may degrade over time due to prolonged exposure to environmental factors, gradually compromising their performance and structural integrity. Deterioration processes that include chloride-induced corrosion, freeze-thaw cycles, and exposure to aggressive environments have been widely recorded, often resulting in brittle failures as a drastic outcome (Bijen, 2003;Krentowski, 2021;Alexander and Beushausen, 2019). It is known that the presence of cracks significantly impacts the durability of concrete. ...
This paper investigates the intrinsic ability of PVA fiber-reinforced cementitious composites to re-establish the durability properties of the uncracked state. Comparative chloride penetration tests are used as a direct measure to quantify the effect of self-healing on the chloride penetration resistance after cracking. Two different composites with cement to fly ash ratios of 1:1.5 and 1:2.0 were studied under the influence of healing periods of up to 28 days. After inducing cracks between 100 and 120 μm, samples were exposed to chlorides for 72 h and the resulting chloride penetration depth was compared to the unhealed state. Based on this procedure, a durability recovery index was proposed to quantify the material’s ability to re-establish its function as a protective layer after cracking. Results show that after 14 days of self-healing, chloride penetration through cracks was reduced between 81% and 99%. An extended healing period of 28 days leads to further reduction of the penetration depth to 84%–100%, indicating that most of the reaction takes place within the first 14 days of healing. While the stiffness recovery analysis showed that increasing cement content by 20% correlated with the formation of stronger healing products, no significant difference was found regarding crack closure.
... Hence, to achieve optimal and secure industrial design of AM component, it is necessary to thoroughly examine the impact of corrosion and HE on fatigue propeties [116]. Assesment of enduring corrosion fatigue strength of structural materials under operational conditions is a crucial challenge for design engineers [117]. The combined effects of mechanical fatigue and environmental conditions may be more detrimental than the individual impacts of each mechanism in isolation. ...
Understanding the impact of hydrogen embrittlement (HE) on the mechanical properties of additively manufactured (AM) metals is of utmost importance for industries utilizing these materials, including critical hydrogen transportation and storage applications. This comprehensive review paper explores the effects of HE on AM alloys, emphasizing the crucial role of microstructure and its influence on HE and hydrogen-induced crack initiation (HICI) and propagation processes. Recent studies indicate that the HE in AM metals may deviate from that observed in conventionally manufactured (CM) metals. The unique characteristics of AM processes may introduce additional factors that affect the complex hydrogen-materials interactions and HE. The hydrogen accumulation at phase interfaces and local reaching of the critical hydrogen concentration represents the primary reason for HICI in AM metals. The specific microstructure of AM and interfaces between phases in the microstructure present crucial factors that influence the HE of AM metals. The interface between phases, which serves as a material structure discontinuity and a location for misfit energy within the structure, can play a critical role in the drop of the HE resistance of certain materials (e.g., martensite/austenite interface in stainless steels, ferrite/perlite interface in low carbon steels, α/β interface in titanium alloys, γ′/ γ″ interface in nickel-based
alloys, etc.). Titanium and nickel alloys demonstrate comparable microstructural features concerning HE due to the laminar phase structure that develops during heat treatment and the secondary phase allotropy in both metals. However, stainless steels, such as SS316 and SS304, follow a distinct mechanism where austenite to martensite transformation predominantly governs hydrogen embrittlement. It is noteworthy that the effect of hydrogen embrittlement in additively manufactured metals seems to be less pronounced compared to CM metals. A comprehensive investigation of HE mechanisms and their interaction with microstructure according to the HELP + HEDE model can provide valuable insights into the susceptibility of AM metals to HE and HICI. This review underscores the need for continued investigation to ensure the reliable performance of AM metal components exposed to hydrogen and HE in various industrial applications. Also, it provides an in-depth understanding of hydrogen embrittlement in AM metals, providing recommendations for the design, development, and safety introduction of new additively manufactured alloys in hydrogen-based energy solutions. Finally, a
perspective on future necessary experiments for exploring the influence of porosity in AM metals on HE, hydrogen-induced crack initiation, and other hydrogen damage mechanisms, including its interaction with microstructure, is given.
... However, from a software engineering perspective, defining software sustainability as its capacity to endure is simplistic and requires greater precision if we are to engineer software systems. It is worth noting that other engineering disciplines would refer to this quality as durability (Bijen, 2003). Reframing the discussions around this might serve for clarity if the field of software engineering also adopted the same terminology (Atkins and Escudier, 2013). ...
... Construction errors dominate the cause of accidents, and it has been revealed that gross errors cause 80 to 90% of failures to buildings, bridges, and other civil engineering structures (Matousek and Schneider 1976;Lopez et al. 2010). Bijen (2003) identified that engineering failures account for as much as 10% of the total investment in new buildings and structures. Importantly, these failures are not restricted to simple direct cost considerations because they are also inextricably linked to less tangible environmental and social costs. ...
Deviations in construction have long been a debatable issue in construction projects. However, only
a few formal studies have been carried out to analyse its causes and effects. This study is focused on the
identification and quantification of various factors causing Deviations in construction of a multi-level
commercial project. It is important for a company not only to know the deviation costs, but also to identify the
most likely areas on which to focus in order to reduce these costs for the future projects. All the necessary data
and information are obtained from site records along with the revised, approved site drawings, indicating the
new change and addition or omission of specified work. The deviation factors are individually compared and
quantified. Most of the research studies have been dealing with several factors that cause deviations in the
project. The objective of this study is to identify the main cause of the cost and schedule deviation. The
approach to serve the objective is achieved by collecting data regarding “Granite cladding works” from a large
construction project in order to identify the cause of project cost and schedule deviation.
... Over the last few decades, durability of concrete structures has become a key aspect in the design of new structures and the repair of existing ones. 1,2 Many experimental studies can be found in the literature dealing with different kinds of degradation processes, such as chloride ingress, carbonation, or sulfate attack. 3,4 Sulfate attack on concrete is a complex process. ...
Sulfate attack on concrete considerably affects the lifetime of
concrete structures. The critical content of ettringite at which a
considerable decreasing of compressive strength is created in this
research. An experimental program on cement paste and concrete
was carried out. To accelerate the magnesium sulfate attack,
magnesium sulfate salt was added to the paste and concrete at
the mixing stage. A theoretical chemical method was suggested to
calculate the ultimate ettringite content. The experimental cement
paste stage, with 24 mixtures, was tested to verify the results of this
method. The ettringite content was measured using X-ray diffrac-
tion testing and compared with the theoretical method. Fifteen
concrete mixtures were tested to study the effect of accelerated
ettringite on mechanical properties and expansion. The studied
variables included, C3A contents and relative magnesium sulfate
addition. From this study, there is a good agreement between the
proposed method and experimental results. The critical ettringite
content ranges from 45 to 66 kg/m3 and depends on C3A content.
... Natural deterioration causes decreased performance in construction materials; however, it is often considered a second or forgotten topic during the design phase (Bijen, 2003). The primary tests for the durability of materials incorporating WTS are discussed, based on studies which have been carried out on the long-term life cycle. ...
Water treatment sludge (WTS) management is a growing global problem for water treatment plants (WTPs) and governments. Considering the scarcity of raw materials in many parts of the planet and unique properties of WTS, extensive research has been conducted on the application of WTS in the production of construction materials such as roof tiles, bricks, lightweight aggregates, cement, concrete and geopolymers. This paper critically reviews the progress in the application of WTS in construction materials, by synthesizing results from recent studies. Research findings have revealed that incorporation of ≤10% alum-based sludge in ceramic bricks is satisfactory with a small reduction of mechanical performance. Using the iron-based sludge, the bricks presented better mechanical strength than the reference clay-bricks. Concerning WTS application in concrete, 5% replacement of cement or sand by WTS was considered as the ideal value for the application in a variety of structural and non-structural concrete without adverse effect on concrete mechanical performance. Furthermore, this paper discusses sludge-amended concrete in terms of durability, potential leaching of toxic elements and cost, and suggests topics for future research on the sustainable management of WTS.
... Natural deterioration causes decreased performance in construction materials; however, it is often considered a second or forgotten topic during the design phase (Bijen, 2003). The primary tests for the durability of materials incorporating WTS are discussed, based on studies which have been carried out on the long-term life cycle. ...
... Natural deterioration causes decreased performance in construction materials; however, it is often considered a second or forgotten topic during the design phase (Bijen, 2003). The primary tests for the durability of materials incorporating WTS are discussed, based on studies which have been carried out on the long-term life cycle. ...
Water treatment sludge (WTS) management is a growing global problem for water treatment plants (WTPs) and governments. Considering the scarcity of raw materials in many parts of the planet and unique properties of WTS, extensive research has been conducted on the application of WTS in the production of construction materials such as roof tiles, bricks, lightweight aggregates, cement, concrete and geopolymers. This paper critically reviews the progress in the application of WTS in construction materials, by synthesizing results from recent studies. Research findings have revealed that incorporation of ≤10% alum-based sludge in ceramic bricks is satisfactory with a small reduction of mechanical performance. Using the iron-based sludge, the bricks presented better mechanical strength than the reference clay-bricks. Concerning WTS application in concrete, 5% replacement of cement or sand by WTS was considered as the ideal value for the application in a variety of structural and non-structural concrete without adverse effect on concrete mechanical performance. Furthermore, this paper discusses sludge-amended concrete in terms of durability, potential leaching of toxic elements and cost, and suggests topics for future research on the sustainable management of WTS.
... In addition, an extremely warm climate could increase a chemical attack on prestressed concrete. For example, the concentration of CO 2 will increase in a warm climate, which increases the possibility of carbonation on concrete sleepers [30][31][32][33]. It is thus necessary to account for durability that fulfils the performance requirements demanded during a sleeper's service life. ...
Railway networks are exposed to various environmental conditions. It is thus critical that infrastructure components can tolerate such effects by design. Railway sleepers are a critical safety component in ballasted track systems. Prestressed concrete is currently the most common material for railway sleepers due to its superior advantages in structural performance, low maintenance, sustainability, and construction. In practice, many prestressed concrete sleepers are installed in harsh environments that are subject to various changes in climate. Environmental conditions are, therefore, one of the most critical phenomena affecting the time-dependent behaviour of prestressed concrete sleepers. Hence, the impact of climate changes on the serviceability of railway infrastructure needs to be thoroughly investigated. Temperature and relative humidity are crucial aspects that have not been sufficiently studied so far with reference to prestressed concrete sleepers embedded in track systems. This study aims to investigate the effects of extreme climatic conditions on the performance and time-dependent behaviour of prestressed concrete sleepers using contemporary design approaches. The issue concerning the effects of climate uncertainties on creep and shrinkage is rigorously investigated on the basis of both environmental temperature and relative humidity. The outcome indicates that environmental conditions play a vital role in the time-dependent behaviour of prestressed concrete sleepers. The insights will be essential for assessing the long-term serviceability of prestressed concrete sleepers that have been installed in railway lines and are subjected to extreme environmental conditions.
... Chloride ions can penetrate from the exterior if concrete is in contact with sea water or road structure in contact with de-icing salts. They can also the present in concrete from the very beginning, e.g., when calcium chloride is applied as an accelerator or when beach sand contaminated with salt is used as a fine aggregate [10]. ...
... Chloride ions can penetrate from the exterior if concrete is in contact with sea water or road structure in contact with de-icing salts. They can also the present in concrete from the very beginning, e.g., when calcium chloride is applied as an accelerator or when beach sand contaminated with salt is used as a fine aggregate [10]. ...
A study on green concrete as well as its durability is essential to promote the sustainable development of the concrete industry. Since the majority of concrete deterioration is connected to corrosion of reinforcement due to carbonation or chloride penetration into concrete, the influence of pozzolan through them must be investigated for concrete durability. This paper mainly focuses on the experimental study of the influence of Popa volcanic natural pozzolan on carbonation and chloride penetration process. The experimental tests are made on replacement of natural pozzolan 10%, 20%, 30% instead of cement and analysis show that optimized pozzolan replacement can promote on the mechanical strength of concrete along with time than reference concrete. According to the results, in the CO2 chamber and the natural condition, it contributes negatively to carbonation because the rate of carbonation increased as the amount of pozzolan increased. However, increasing the pozzolan content led to higher resistance of the concrete in chloride ion penetration.
... The design stage of a project should be given careful attention because when this is not done deterioration will often set in easily and too early. According to Bijen (2003), this is based on the fact that designing for the service life of structures in most standards and codes of design do not cover information about materials, their long term behaviour and the building elements which could really help in dealing with this problem of structural durability. However, with the changes in temperature due to global warming, infrastructure especially road may deteriorate faster. . ...
... In that paper, the authors presented environmental corrosion rates for different parts of the metropolitan area of Salvador, including the location considered in this study, which has a high environmental factor rate of 3,231 mg Cl/m 2 /day and is situated in a zone where all exposed ferrous metals are subject to corrosion. Bijen (2003) stated that civil engineering failures not only exemplify important cost considerations but also carry an environmental burden. Structures often deteriorate because the required attention is not always present during the design stage, and most standards for structural design do not cover a lifecycle plan. ...
Due to the climate and the proximity to the sea, the environment of the city of Salvador creates a condition very unfavorable to the metallic components of every order before oxidation processes that may develop. In this context, the structures require a special condition maintenance, aiming not only extend the life of the building, but also ensure the structural safety. The wooden structures are attractive option for environments such as the conditions of inspection and maintenance are easier to be performed and are less costly. This paper describes the design of a timber used to replace another metal that collapsed. The collapsed structure was situated in environmental conditions of high level of aggressiveness, being distant about 100 meters from the seaside. The original had a metal structure nearby area of 300 m 2 and collapsed in May 2013, after 07 years of use, completely destroying the superstructure and reinforced concrete columns. The builders called to rebuild the coverage chosen by the use of wooden structure, whose design solutions constitute the basis for this discussion.
... According to Solatiyan et al. [27], if the resulting stress is greater than the intrinsic tensile strength of reinforced concrete, a crack will occur. Moreover, if low temperature continues, the cracks will develop considerably [28]. High temperature also can have an influence on the performance of concrete. ...
For modern infrastructures, structural concrete has been widely adopted for various components and structures such as railway stations, platforms, walkways, railway bridges, tunnelling, concrete sleepers, concrete foundation of overhead wiring structures, etc. These infrastructures are subject to various changes of time, operation, and environment. Environmental conditions are a considerably influential factor to life cycle and durability of concrete structures. This study aims at identifying the influence of climate change on the performance and durability of concrete structures using statistical regression analysis of a number of pertinent experimental and field data. The study into the influence of elevated temperature on compressive strength and splitting tensile strength also has been carried out using experimental data on the basis of environmental temperature and relative humidity, as well as CO2 concentration to the concrete carbonation and steel corrosion rates. The results indicate that environmental temperature, CO2 concentration, and a certain range of relative humidity play an important role in the concrete carbonation rates. Temperature and relative humidity affect the rate of steel corrosion as well. In addition, it is found that there exists a nearly direct correlation between the environmental temperature and the concrete carbonation rates, as well as the corrosion rate of steel embedded in concrete from 25 °C to 60 °C, and a nearly inverse proportion between the environmental relative humidity and the concrete carbonization from 48.75% to 105%. Indeed, the results exhibit that even in extreme natural high temperature, the capacity of compressive strength and splitting tensile strength is not affected significantly.
... Steel is used for a significant number of components that compose the main frame and body of rail car bodies. Its life cycle and deterioration must be identified prior to recycling, as shown in Figure 4 [23]. The production of the steel involves a large number of preparation activities. ...
... This results from their high resistance to atmospheric conditions. Depending on the type of fibres and the matrix, FRP elements may be resistant both to acids and bases [3]. This allows to construct bridge structures in aggressive environments, where traditional structures fail. ...
The paper presents development of concept of prefabricated composite decks evolved by the consortium implementing the PANTURA research project co-financed by the European Commission. In the Research and Development Department of Mostostal Warszawa S.A., prototype panels have been manufactured using epoxy resin reinforced with fibres (glass and carbon) and foam cores. The sandwich panels have been made by using the infusion process. The paper confirms that it is possible to use this method to produce bridge deck panels as well as presents the problems encountered and experiences gained in the course of manufacturing prototype models of them.
... Steel is used for a significant number of components that compose the main frame and body of rail car bodies. Its life cycle and deterioration must be identified prior to recycling, as shown in Figure 4 [23]. The production of the steel involves a large number of preparation activities. ...
The railway industry is one of the most important sectors driving growth of regional economies worldwide. The industry has long dealt with both infrastructure and rolling stock. Many of these have reached the end of their lives. This paper highlights the rail policy for managing end-of-life rail vehicles. Initially when manufacturing rolling stock, different materials are considered in design and manufacture such as steel, aluminum, copper, polymers, glass. Based on the high economic and carbon costs of these materials, it is worthwhile to reuse or recycle them after their end-of-life cycle. In this study, three types of trains have been evaluated for comparison: freight, passenger and high speed. The material breakdowns from rail vehicles are evaluated for feasible applications in terms of reusing or recycling train components. We consider every material, taking into account the process of production, remaining life, advantages, disadvantages and potential threats derived from using such residual materials. The key aspects are risks and uncertainty associated with chemical and physical processes, corrosion and its varieties, oxidation, impact on the environment, release of toxicity, and pollution to the soil. These negative effects can indeed harm people, children, and assets in the vicinity. This paper therefore highlights the possibilities of recycling residual materials derived from rolling stock waste and any danger to the environment and the community, so that hazardous waste management can be put in place at the right time. Such insight will better shape sustainability policy for rolling stock procurement in the future.
... Degradation can, for instance, be caused by wear, fatigue, creep, and corrosion and can, to a certain extent, be influenced by the design of the product and its components (Goel and Singh 1997). Durability is a physical property of a product, and design for durability has been researched quite extensively (see, e.g., Keoleian and Menery 1993;Bijen 2006;Vezzoli and Manzini 2008). ...
In a circular economy (CE), the economic and environmental value of materials is preserved for as long as possible by keeping them in the economic system, either by lengthening the life of the products formed from them or by looping them back in the system to be reused. The notion of waste no longer exists in a CE, because products and materials are, in principle, reused and cycled indefinitely. Taking this description as a starting point, the article asks which guiding principles, design strategies, and methods are required for circular product design and to what extent these differ from the principles, strategies, and methods of eco-design. The article argues that there is a fundamental distinction to be made between eco-design and circular product design and proceeds to develop, based on an extensive literature review, a set of new concepts and definitions, starting from a redefinition of product lifetime and introducing new terms such as presource and recovery horizon. The article then takes Walter Stahel's Inertia Principle as the guiding principle in circular product design and develops a typology of approaches for Design for Product Integrity, with a focus on tangible durable consumer products. The newly developed typology contributes to a deeper understanding of the CE as a concept and informs the discussion on the role of product design in a CE.
... Currently, 5 to 10% of the amount of the total investment in new buildings and structures is lost by civil engineering failures (Bijen 2003). These failures result in significant cost considerations, and also have an associated environmental damage. ...
The durability of buildings which depends on the nature of the supervisory system used in their construction is an important feature of the construction industry. This article tries to draw the readers' attention to the effect of untrained and unprofessional building supervisors and their unethical performance on the durability of buildings.
... The largest industry in the world is covered by civil infrastructure and has about 10% share in the GDP [1] . As a result, technical textiles for this market may govern an important turnover. ...
The MULTITEXCO project aims at characterizing and demonstrating the latest achievements in technical textiles for their applicability in the construction sector. This will support the SMEs involved in the construction sector to fully exploit the new generation of multifunctional technical textiles. The project is focusing on applications of smart textiles in 1/ roadwork and embankments, 2/ structure retrofitting and 3/ fabrics for tensile structures. For each field of application a demonstrator is exemplifying the use and reliability of novel, smart multifunctional fabrics. Especially for this contribution, attention will be paid to the application of such smart fabrics in tensile structures.
... In that paper, the authors presented environmental corrosion rates for different parts of the metropolitan area of Salvador, including the location considered in this study, which has a high environmental factor rate of 3,231 mg Cl/m 2 /day and is situated in a zone where all exposed ferrous metals are subject to corrosion. Bijen (2003) stated that civil engineering failures not only exemplify important cost considerations but also carry an environmental burden. Structures often deteriorate because the required attention is not always present during the design stage, and most standards for structural design do not cover a lifecycle plan. ...
This paper describes the challenges and solutions for the design and implementation of a timber structure to replace a collapsed steel structure. Wood was chosen as the structure material because it is suited for environments with high salinity and, in this context, for reducing maintenance costs. One of the most important challenges of this project was that the beam should have a long span and the wood should be able to attain the ultimate limit state and serviceability given the dimensions in the project. The entire roof was supported only by four columns, which forced the side and frontal beams to exceed span lengths of 18 m without intermediate supports. A mathematical computational model was constructed using the FEM to obtain the loads on the structural elements. During the implementation process, many parts were implemented differently from the original design, which needed to be reinforced. It is important to emphasize that the design of a wooden structure requires not only knowledge but also creativity to overcome the challenges posed by the distinctive needs of detailing and difficulty that carpenters have in reading the specific plans.
... The largest industry in the world is covered by civil infrastructure and has about 10% share in the GDP [1] . As a result, technical textiles for this market may govern an important turnover. ...
The MULTITEXCO project aims at characterizing and demonstrating the latest achievements in technical textiles for their applicability in the construction sector. This will support the SMEs involved in the construction sector to fully exploit the new generation of multifunctional technical textiles. The project is focusing on applications of smart textiles in 1/ roadwork and embankments, 2/ structure retrofitting and 3/ fabrics for tensile structures. For each field of application a demonstrator is exemplifying the use and reliability of novel, smart multifunctional fabrics. Especially for this contribution, attention will be paid to the application of such smart fabrics in tensile structures.
... Design errors dominate the cause of accidents, and it has been revealed that gross errors cause 80 to 90% of failures to buildings, bridges, and other civil engineering structures (Matousek and Schneider 1976; Lopez et al. 2010). Bijen (2003) identified that engineering failures account for as much as 10% of the total investment in new buildings and structures. Importantly, these failures are not restricted to simple direct cost considerations because they are also inextricably linked to less tangible environmental and social costs. ...
... Hansson [3] prepared a study where he looked at over 127 failures cases and their modes of timber structures collapse, and concluded that the most common cause for failure (41.5%), is related to weakness in the project definition or mistakes on the strength of the design, followed by poor principles during assembly (14.1%), on-site alterations (12.5%), and insufficient data regarding the various environmental facets (11.4%). In total, about half of the failures are caused by the designer, and about one fourth of them are caused by personnel at the building site. ...
... They can also incur more cost that adds a project's value around 14.2% [6][7][8]. Design errors are a serious threat to construction projects [5,[9][10][11]. Besides, the use of technology is limited in construction development in Cambodia because of inadequate human resources and limited education system. This is a reason that the occurrence of design errors cannot be effectively controlled and can greatly affect the construction process. ...
... In summary, the most common surface treatments use polymeric resins based on epoxy, silicone (siloxane), acrylics, chlorinated rubber, polyurethanes or polymethacrylate. Bijen (2000) mentioned that the epoxy resins have low resistance to ultraviolet radiation and polyurethanes are sensitive to high alkalinity environments. Polyurethane is obtained from the isocyanates, known worldwide for its tragic association with the Bhopal disaster. ...
This article presents results of an experimental investigation on the resistance to chemical attack (with sulphuric, hydrochloric and nitric acid) of several materials: OPC concrete, high-performance concrete, epoxy resin, acrylic painting and a fly ash-based geopolymeric mortar). Three types of acids with three high concentrations (10, 20 and 30%) were used to simulate long-term degradation. A cost analysis was also performed. The results show that the epoxy resin has the best resistance to chemical attack independently of the acid type and the acid concentration. However, the cost analysis shows that the epoxy resin-based solution is the least cost-efficient solution being 70% above the cost efficiency of the fly ash-based geopolymeric mortar.
... Recently Brenna et al [10] study The efficiency of four commercial concrete coatings (a polymer modified cementitious mortar and three elastomeric coatings) against chloride-induced corrosion concluding that the polymer containing mortar shows the best effect on delay chlorides penetration in concrete.In summary the most common surface treatments use polymeric resins based on epoxy, silicone (siloxane), acrylics, chlorinated rubber, polyurethanes or polymethacrylate. Bijen [11] mentioned that the epoxy resins have low resistance to ultraviolet radiation and polyurethanes are sensitive to high alkalinity environments. Polyurethane is obtained from the isocyanates, known worldwide for its tragic association with the Bhopal disaster. ...
The construction industry is responsible for high energy and raw materials consumption. Thus, it is important to minimize the high energy consumption by taking advantage of renewable energy sources and reusing industrial waste, decreasing the extraction of natural materials. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing to the thermal comfort and reduction of the use of heating and cooling equipment, using only the energy supplied by the sun. The simultaneous incorporation of PCM and fly ash (FA) can reduce the energetic consumption and the amount of materials landfilled. However, the addition of these materials in mortars modifies its characteristics. The main purpose of this study was the production and characterization in the fresh and hardened state of mortars with incorporation of different contents of PCM and FA. The binders studied were aerial lime, hydraulic lime, gypsum and cement. The proportion of PCM studied was 0%, 20%, 40% and 60% of the mass of the sand. The content of fly ash added to the mortars was 0%, 20%, 40% and 60% of the mass of the binder. It was possible to observe that the incorporation of PCM and fly ash in mortars caused differences in properties such as workability, microstructure, water absorption, compressive strength, flexural strength and adhesion.
... They can also incur more cost that adds a project's value around 14.2% [6][7][8]. Design errors are a serious threat to construction projects [5,[9][10][11]. Besides, the use of technology is limited in construction development in Cambodia because of inadequate human resources and limited education system. This is a reason that the occurrence of design errors cannot be effectively controlled and can greatly affect the construction process. ...
Design errors are unavoidable in any construction projects and can negatively affect cost, schedule and safety performance. The different types of design drawings may have various levels of design errors due to many factors such as unclear overview of the designs, lack of coordination process, and human mistakes. Civil engineers, both designers and contractors, have limited understanding of the importance of design errors that occur in construction phases. This paper attempts to evaluate the impact level of groups of design errors in structural and other building components and also the impact level of their cases which occur in building construction projects in Cambodia. Respondents were asked to provide the impact score for design errors based on the five-point Likert scale, ranked from 1-negligible to 5-disastrous. The average impact score was determined in order to rank the impact of design errors. As a result, design errors in structural and mechanical works are found as the first group to be focused due to its impact, followed by design errors in structural and plumbing works. The top three cases under the group of design errors in structural and mechanical works are those in reinforced concrete walls and lift systems, footing and lift systems, and slab and HVAC systems. These results are significant for engineers to be aware of the possible high impact of design errors, and also to determine which group of design errors should be considered first. Further studies should look at the combination of such occurrence and impact of design errors in order to efficiently identify the most critical and significant design errors in terms of not only their impact, but also their occurrence in building construction projects.
... Bijen [11] mentioned that the epoxy resins have low resistance to ultraviolet radiation and polyurethanes are sensitive to high alkalinity environments. Polyurethane is obtained from the isocyanates, known worldwide for its tragic association with the Bhopal disaster. ...
Premature degradation of ordinary Portland cement (OPC) concrete infrastructures is a current and serious problem with overwhelming costs amounting to several trillion dollars. The use of concrete surface treatments with waterproofing materials to prevent the access of aggressive substances is an important way of enhancing concrete durability. The most common surface treatments use polymeric resins based on epoxy, silicone (siloxane), acrylics, polyurethanes or polymethacrylate. However, epoxy resins have low resistance to ultraviolet radiation while polyurethanes are sensitive to high alkalinity environments. Geopolymers constitute a group of materials with high resistance to chemical attack that could also be used for coating of concrete infrastructures exposed to harsh chemical environments.This article presents results of an experimental investigation on the resistance to chemical attack (by sulfuric and nitric acid) of several materials: OPC concrete, high performance concrete (HPC), epoxy resin, acrylic painting and a fly ash based geopolymeric mortar. Two types of acids, each with high concentrations of 10%, 20% and 30%, were used to simulate long term degradation by chemical attack. The results show that the epoxy resin had the best resistance to chemical attack, irrespective of the acid type and acid concentration.
... The design, construction, maintenance and repair of civil infrastructure is the largest industry in the world representing approximately 10% of world GDP [1].Technical textiles designed for this market can therefore attribute to an important turnover. Textile materials are used in construction in both ground and building structures. ...
Abstract The overall objective of the MULTITEXCO project is to scientifically and technologically characterize the latest achievements within the technical textile sector for the development of Guidelines and Pre-normative research, enabling future standards at EU level. These will support the SMEs involved in the construction sector to fully exploit the new generation of multifunctional technical textiles. MULTITEXCO is focusing on key developments in smart textiles for 1/ roadwork and embankments, 2/ structure retrofitting and 3/ fabrics for tensile structures. For each field of application a demonstrator is exemplifying the use and reliability of novel, smart multifunctional fabrics for the construction sector. In this contribution we will show examples for all three application areas, such as for example the use of textile integrated sensors for tensile architecture applications, sensor embedded soil reinforcing fabrics and meshes for masonry retrofitting.
... The most common polymers used in the manufacture of pre-mix PCCs include (Bijen, 2003) j acrylic polymers -acrylic polyesters (PAE) j styrene-acrylic copolymers (SAE) j styrene-butadiene copolymers (SB) j polyvinyl acetate (PVA) j vinyl acetate copolymers: polyethylene vinyl acetate (PEVA) and vinyl ester of versatic acid (VEOVA). ...
The paper deals with test results of the influence of Penicillium chrysogenum and Cladosporium herbarum fungi on the mechanical and sorption properties of cement mortars CEM I and the mortars modified by polymers. The corrosion processes were identified by chemical oxygen demand (COD) analysis, by the aid of a scanning microscope with an X-ray microanalyser and by mercury porosimetry. The results presented show a high concentration of the fungi in the mortars, especially in the materials modified by polysiloxane and acrylic polymers. The presence of the fungi greatly influences the useful properties of cement materials. The high growth of these microorganisms significantly influences the mass moisture and absorbability as well as flexural strength, which is strictly connected with these properties. The actions of the filamentous fungi resulted in two opposing processes: the unsealing of the structure and deposition of corrosion products.
... Design errors dominate the cause of accidents, and it has been revealed that gross errors cause 80 to 90% of failures to buildings, bridges, and other civil engineering structures (Matousek and Schneider 1976;Lopez et al. 2010). Bijen (2003) identified that engineering failures account for as much as 10% of the total investment in new buildings and structures. Importantly, these failures are not restricted to simple direct cost considerations because they are also inextricably linked to less tangible environmental and social costs. ...
Design errors can adversely influence project performance and can contribute to failures, accidents, and loss of life. Although there has been a considerable amount of research that has examined design error causation, little is known about design error costs. With increasing emphasis placed on the use of nontraditional forms of procurement methods as a result of various government reports and the advent of Building Information Modelling there is a general perception that design error costs will be significantly less than those projects procured by traditional means. By using a questionnaire survey, estimates for design error costs were obtained from 139 projects. The mean direct and indirect costs for design errors were revealed to be 6.85 and 7.36% of contract value, respectively. Design error costs were found not to significantly vary with procurement method and project type used. Although the research provides invaluable insights into practitioners' perceptions of design errors costs, their actual costs remain relatively unexplored. DOI: 10.1061/(ASCE)CO.1943-7862.0000454. (C) 2012 American Society of Civil Engineers.
... The most common surface treatments use polymeric resins based on epoxy, silicone (siloxane), acrylics, polyurethanes or polymethacrylate . Bijen [29] mentioned that the epoxy resins have low resistance to ultraviolet radiation and polyurethanes are sensitive to high alkalinity environments. On the other hand although some waterproof materials are effective for a particular transport mechanism (diffusion, capillarity, permeability) cannot be for another. ...
Background
Concrete is a widely utilized material in construction worldwide. However, concrete performance could be damaged under aggressive environments, therefore, many concrete structures may require repair and frequent maintenance.
Objective
The aim of this study is to develop reinforced Self-Consolidating Repair Mortars (SCRMs) incorporating silica fume and polypropylene fibers.
Methods
This research aimed to study the effect of silica fume as an alternative supplementary cementitious material (SCM) on the performance of fiber reinforced self-consolidating repair mortars (SCRMs). For this purpose, five SCRMs mixes incorporating 0%, 5%, 10%, 15%, and 20% of silica fume as partial cement replacement were prepared. Testing included slump flow, flow time, and unit weight, air-dry unit weight, compressive and flexural strengths, dynamic modulus of elasticity and water absorption.
Results
The results indicated that the substitution of cement by 15% of silica fume improves the flexural strength and slightly reduce the compressive strength of the fiber-reinforced repair mortar. The lowest values of total shrinkage, water capillary absorption, and sorptivity were observed for repair mortars containing 10% silica fume. In addition, bonding results between repair mortars containing silica fume and old concrete substrate investigated by the bond flexural strength test showed good interlocking, justifying the effectiveness of these produced mortars.
Conclusion
The results reveal that structural repair mortars containing 10 and 15% silica fume conform with the performance requirements of class R4 materials (European Standard EN 1504-3) and could be used in repair applications.
The development of efficient weigh-in-motion and wheel defect detection methods with high accuracy estimation procedures from track measurements is one of the major subjects that draw the attention of both the railway industry and scientific researchers. This information triggers a warning in the administration system when a train is overloaded or operating under abnormal conditions. The main novel aspect of this study is to define a methodology to obtain weigh the train in motion and allows the identification of a wheel flat using a wayside monitoring system. To achieve this, two approaches were proposed to obtain an estimation of the wheel static load as well as distinguish the healthy wheel from the defective one in order to allow the system to activate the necessary alerts. A wide range of numerical simulations based on a train-track interaction model has been performed for different train speeds. From the obtained results, it is evident that the proposed approaches are capable tools and cost-effective methods to estimate the wheel static load as well as an abnormal condition of rolling stock.
The study investigated the effects of temperature on strength of concrete produced in Anambra State, Nigeria. The study is an experimental research. Concrete were produced at different temperature within the study area. Cement, aggregates (fine and coarse) and water were used in mixing concrete. Dangote Cement was used for all the concrete produced. The fine aggregates used was obtained from River Sand (Onitsha), coarse aggregate is crushed stones from Nkwelle Ezunaka and water used for the concrete mixing is fit for drinking. These concrete produced were tested in the laboratory (Anambra State Material Testing Laboratory) for workability and compressive strength and the result obtained were presented in simple tables and graphs. The study found out that there is great variation in strength of concrete produced at different temperatures. The average compressive strength at 27.6 0 C is 14.83N/mm 2. At temperatures above 30 0 C, the strength of concrete tends to diminish/reduce. Compressive strength of concrete at 33.85 0 C and 35.1 0 C was 11.6N/mm 2 and 11.1N/mm 2 respectively. Also, the result of the slump value ranges from 48.4mm-103.5mm (indicating that all the concrete mix is workable). The graph in Figure 3 indicates that concrete produced in early hours of the day yielded the highest compressive strength (28 th day) while as temperature increases, the compressive strength of concrete diminishes. The study was concluded by recommending that the best time for concrete production is in the morning when atmospheric temperature is still below 30 0 C within the study area. From the results of the study, it can be clearly noticed that with increase in temperature, there is there is significant increase slump of concrete mix as well as decrease in crushing load and compressive strength of concrete.
Mechanical, durability and microstructure properties of fiber reinforced
self-compacting concrete (FRSCC) were investigated in the scope of this study.
Flexural and compressive performance were determined as mechanical properties.
Microstructural analyses were performed on the specimens that were exposed to the
freeze – thaw (F-T) effect.
The effects of fifty percent (wt.) ground granulated blast furnace slag
replacement, two different types of steel fiber (macro and micro) and air entraining
admixture on mechanical performance and F-T durability were studied. Dosage of
steel fiber was forty kilograms per cubic meter and hybrid usage of macro and micro
fibers were also studied. Fresh state test results showed that GGBFS has an
improvement effect on rheological properties. Steel fibers affected fresh state
performance adversely and this negative effect gets more important with an
increasing of fiber aspect ratio. Steel fiber usage generally improved mechanical
properties. GGBFS replacement exhibited better mechanical performance than only
cement binder usage at later ages. Steel micro fibred self-compacting concrete
exhibited deflection softening but macro fiber usage caused deflection hardening
behavior under flexural loading. Morever steel fibers changed fracture behavior of
plain concrete completely and fracture energy values of FRSCC were from twenty to
ninety times of plain self-compacting concrete (SCC) specimens. The best
performance from the point of fracture energy was exhibited by macro fiber usage.
All SCC and FRSCC series showed satisfactory F-T resistance. High amount of
GGBFS as an industrial by-product can be used in SCC without important
mechanical loss due to F-T cycles.
The use of existing mathematical models - deterministic: Life-365, Chlodif, and probabilistic: DuraCrete - in the analysis of life span of reinforced-concrete structures exposed to the action of chlorides, as based on physical model of chloride transport in concrete, are presented. The analysis of chloride content, conducted at the Krk Bridge, is presented in the experimental part of the paper. Results obtained by deterministic and probabilistic approaches are compared, and steps for further development of modelling procedures are proposed.
This chapter discusses the pathology, durability and rehabilitation of concrete and also the conservation of renders in ancient buildings. The importance of cracks for the reduction of concrete durability is analyzed, followed by a description of the degradation mechanisms for this construction material. Measures to prevent the degradation of concrete are reviewed, including surface treatments and the use of electrochemical treatments to protect the steel reinforcement against corrosion. Regarding the renders in ancient buildings, particular attention is given to the crystallization of soluble salts. For these materials, the identification of its constituents and the requirements of conservation mortars are addressed.
Corrosion and mechanically damaged bridge pilings in Florida coastal waters have, since the 1940's, been repaired and rehabilitated by jacketing; that is, by 1) removing loose concrete, 2) placing a formwork about the damaged zone (usually from mean low water to a height of several meters), and 3) filling the annulus with mortar or concrete. However, removal of jackets from pilings of two bridges that were being rehabilitated revealed that reinforcement corrosion was often severe and structural integrity reduced. Consequently, a condition assessment of jacketed pilings on 19 representative bridges was performed. This involved a visual condition assessment followed by removal of a portion of the jacket and characterization of the underlying condition. The pre and post-inspection conditions were quantified using a Numerical Condition Rating (NCR) with the difference between the two values (ΔNCR) being taken as a measure of the extent to which piling damage was obscured by the jacket. Influences of jacket age, jacket type, pile reinforcement type (prestressed versus conventional), and piling pre-jacketed condition were evaluated. A mechanism for the deterioration is proposed, and a recommendation was made that jacketing be discontinued as a stand-alone piling repair/rehabilitation strategy.
• INTRODUCTION
• FIELD SURVEY AND CONDITION ASSESSMENT
• DETERIORATION MODEL FOR JACKETED PILINGS
• CONCLUSIONS
• ACKNOWLEDGEMENTS
• REFERENCES
The Dutch Ministry of Transport, Public Works and Water Management commissioned INTRON to investigate the cause of the cracking of high-solids epoxy-based coating systems in The Netherlands. Several subjects were addressed: shrinkage caused by evaporating compounds; temperature movements; stresses from restrained deformation; locations where stresses were highest; and measures to avoid further problems. It was found that cracking is caused by stresses from restrained shrinkage as a result of the evaporation of compounds during a stage in which the coating system already had become fairly rigid. Stresses were highest in areas where transitions in coating thickness occurred and changes were seen in the geometry of the structure.