Investigations have shown that the principal cause of the deterioration was corrosion of reinforcing steel due to the presence of chlorides, with marine salts being the main source. The coastal and offshore structures are always in contact with seawater and there are number of physical and chemical deterioration processes takes place. The best concrete reinforcement solution for marine structures. Guide for design concrete marine structures aci 357.
The prediction of deterioration in marine concrete structures is a major challenge. For aircraft hangers, reinforced concrete shells comprising of thin circular slabs and deep edge beams provide an economical solution. Nevertheless, from the time it is formed in the tree, wood is subject to deterioration by a variety of agents. Concrete specification and maintenance strategy for marine. In marine environments, reinforcement corrosion is directly related to the chloride content in the concrete near the steel surface, which should not be greater than 0. A study on deterioration of reinforced cement concrete structures in mumbai. In marine environments, disintegration of concrete and corrosion of steel are the two main forms of deterioration. Deterioration of concrete in marine structure ijir.
Strategy for protection of marine concrete structures against. A major emphasis of the book is on the longterm performance of marine concrete structures that not only represent major infrastructure investment and provision, but are also required to operate with minimal maintenance. Marine concrete structure an overview sciencedirect topics. Specifications for marine structures in hk durability and design life of marine concrete structures factors affecting durability of marine structures conventional specifications for marine concrete durability performance of conventional marine concrete structures development of marine concrete specification durability performance of marine concrete.
Except for some criteria in aci 357r and special ized criteria in other aci guides on durability, there are no comprehensive guidelines or standards that cover the application of concrete in the marine environment for coastal marine structures. Estimation method on deterioration of marine concrete structures. In its natural state, with a ph level of around 12 concrete provides a good measure of protection to embedded reinforcement. Deterioration of concrete structures under marine conditions and their inspection and repair open pdf. The duracrete model has been tested in the field on six marine structures on the dutch coast, from which chloride profiles. A similar effect is caused by alkali aggregate reaction whereby the presence of water in concrete permits a reaction between silica in certain aggregates and the alkalis in cement. This paper describes the deterioration of reinforced concrete structures at a liquefied gassulfur plant that occurred shortly after completion of the construction. The corrosion of steel reinforcement was first observed in marine structures and chemical manufacturing plants. Deterioration of concrete in the marine environment request pdf. Structural deterioration an overview sciencedirect topics. Concrete in marine environments concrete construction. Concrete specification and maintenance strategy for marine structures ir peter leung honorary advisor to standing committee on concrete technology. Environmental deterioration of materials witelibrary home of the transactions of the wessex institute, the wit electroniclibrary provides the international scientific community with immediate and permanent access to individual. Durability of marine concrete in libya field study on five seaports abdalla o.
Durability of concrete structures an introduction pdf. Although, corrosion of steel reinforcement has been acknowledged as the principal cause of deterioration of marine concrete structures, disintegration of concrete usually accelerate the process of steel corrosion. Climate resilient concrete structures in marine environment. Because of concretes inherent protection, reinforcing steel does not corrode in the majority of concrete elements and structures. Walsh a dissertation submitted in partial fulfillment of the requirements for the degree of doctor of philosophy in civil engineering department of civil and environmental engineering college of engineering university of south florida major professor. Pdf case studies of concrete deterioration in a marine. Deterioration process on marine concrete structures marine environment chloride penetration into concrete passive film on reinforcement is lost reduction of crosssection of reinforcement corrosion of reinforcement starts degradation of structural performance of the structure introduce of corrosion cracking and spalling of concrete water oxygen. Magnesium, sulfate, and chloride ions, and dissolved co2 present in sea water, act as agents of destruction for all the hydration. The steel forms a passive layer which serves to protect it against corrosion. These factors lead to rapid deterioration of concrete and a drastically shortened lifespan. In this paper, the service life of structures exposed to aggressive environments is measured by the probability of cracking and spalling of concrete cover.
These structures need to be designed in such a way that can withstand various loads for example service loads, loads from ships, and loads generated by the impact of sea waves. Different materials such as concrete, stone, timber, and steel have been used for construction of marine structure. Corrosion of steel in submerged concrete structures by michael t. Guideline for service life design of structural concrete. Corrosion and deterioration of many concrete structures can be attributed to construction quality and design parameters. Corrosion of reinforcement is the main cause of deterioration of rc structures located in marine environments or subjected to deicing salts. Corrosion of reinforcing steel is the most common cause of concrete. This guideline entitled guidelines on strategic maintenance for port structures aims at providing developing countries, particularly asean countries, with assistance to appropriately maintain their various port structures such as concrete structures and steel structures. Concrete, marine environment, chloride, blast furnace slag cement, reinforcement corrosion, service life, probabilistic model 1 introduction durability of concrete structures in marine environment has been an issue for many decades, due to the perception of sea water as aggressive to concrete and reinforcement and the long.
Most present design codes do not give quantified guidance for. Krystol internal membrane kim is a hydrophilic crystalline admixture used to create permanently waterproof concrete. Pdf the longterm behaviour of concrete structures has shown that their main cause of distress is reinforcement corrosion. However, concrete structures are vulnerable to a number of factors that can cause deterioration. The deterioration of the system is commonly measured with respect to a physical parameter. Strategies for protection of marine concrete against chloride attack while this paper focus on the additional protection measures, the two most important aspects of achieving design life of concrete structures are suitable concrete quality and adequate cover. To make the students to gain the knowledge on quality of concrete, durability aspects, causes of deterioration, assessment of distressed structures, repairing of structures and demolition procedures. Concrete deterioration reinforced concrete is a very versatile construction material. So far as marine structures are concerned, reinforcement concrete needs to be a highly durable and corrosion free structural material demanding little or no maintenance.
Timber, iron and steel and concrete immersed in sea water are exposed to the action of agencies producing damage and deterioration of structures in sea water skip to main content. The following summary discusses potential causes of concrete deterioration and the factors that influence them. Deterioration process on marine concrete structures penetration of chloride into concrete penetration of clvia pores to the interior of concrete cement hydrate binds some of clchemically fredels salt c 3a. Strategy for protection of marine concrete structures. The primary purpose of waterproofing concrete marine structures is the protection of reinforc. The deterioration of reinforced concrete structures is a major problem. Methods that entail estimating concrete deterioration from weather factors in the marine environment 2 by grasping the movement of chloride ions into the concrete 3. Deterioration can result in loss of strength and unsafe conditions. With regard to salt damage to concrete structures, simple methods for dealing with the complicated process of durability can be categorized as follows. Recent experimental developments have provided a better understanding as to how biological and physicochemical processes associated with mid affects the longterm durability and mechanical properties of concrete structures. Cases of comparatively rapid deterioration have usually resulted from failure to consider and.
Guidelines on strategic maintenance for port structures. One of the most aggressive exposure conditions for concrete is the marine. Aggregates in much of the southern part of china are contaminated with gypsum. It is evident that concrete has become an indispensable component of marine structures, ensuring durability and. These 10year exposure tests have shown that the deterioration of reinforced concrete is influenced by characteristics of the concrete as well as the marine environment. Deterioration of reinforced concrete in the marine industrial. Durability of marine concrete in libya field study on five seaports xii dbmc, porto, portugal, 2011 3. Estimation method on deterioration of marine concrete. Gilani 2 abstract the construction practice of marine concrete structures is of a great concern, considering the severe. Concrete exposed to seawater effects and preventions. Corrosion of reinforcing steel and other embedded metals is the. Aalborg universitet deterioration of concrete structures.
Self healing matrix formed by the bacteria excreates calcium components to heal concrete. Concrete has had extensive use as construction material for seawalls, jetties, groins, breakwaters, bulkheads, and other structures exposed to sea water. Properly designed concrete structures are both strong and durable. While this is a positive change, often the quality and the rationale behind the testing are. Without the passive film, the steel would corrode at rates at least 1,000 times higher aci 222 2001. Oct 16, 2014 the present case sudy is about the upcoming marine structures and methods to deal with the deterioration of structures with the help of bacterial injection in concrete.
Unit i maintenance and repair strategies 9 maintenance, repair and rehabilitation, facets of maintenance, importance of. Next prev concrete durability and repair technology. Climate resilient concrete structures in marine environment of bangladesh page 2 the views in this document are those of the authors and they do not necessarily reflect the views of the research for community access partnership recap, or cardno emerging markets uk ltd. Pdf a study on deterioration of reinforced cement concrete. The action of microorganisms on concrete structures can be classified according to their effects on concrete surfaces, concrete matrices, and on cracking and crack growth amann et al. Guideline for service life design of structural concrete a. The present case sudy is about the upcoming marine structures and methods to deal with the deterioration of structures with the help of bacterial injection in concrete. The deterioration of reinforced concrete structures not only depends on the microstructure of the concrete but also on severe exposure conditions in a particular environment. So, concrete structures effected by seawater requires special attention. Concrete can deteriorate for a variety of reasons, and concrete damage is often the result of a combination of factors. Deterioration of concrete structures under marine conditions and their inspection and repair authors.
If you look at the deterioration of concrete as one of the important event, which is. Deterioration process on marine concrete structures. These has been dealt with by chindaprasirt et al 4. Climate resilient concrete structures in marine environment of bangladesh page 2 the views in this document are those of the authors and they do not necessarily reflect the views of the research for community access partnership recap, or cardno emerging markets uk ltd for whom the document was prepared. Corrosion of steel in submerged concrete structures. The concrete structures built in marine conditions are always exposed to seawater either directly or indirectly. Without correct mixing, design, placement, and curing, the durability of concrete can be impaired. Rock, sand, concrete, and steel are some of the conventional materials used in marine applications. Case studies of concrete deterioration in a marine.
Welcome to the lecture 4 on module 3 of ocean structures and materials, a virtual classroom under the. Service life prediction of reinforced concrete structures. Types of marine structures construction details and uses. Once the ph level of concrete falls to 910, the passive layer is disrupted leading to. When critical concentration of free cl accumulates. There are enough evidences to show that a wide variety of organisms can cause concrete deterioration table 1. Materials and methods for corrosion control of reinforced. Deterioration of reinforced concrete in the marine. Deterioration of concrete structures under marine conditions and their inspection and repair.
Deterioration of concrete structures thoftchristensen, palle publication date. Feb 01, 2002 case studies of concrete deterioration in a marine environment in portugal case studies of concrete deterioration in a marine environment in portugal costa, antonio. In coastal areas where corrosion is imminent for the construction of marine structures like platform, quay walls, watchtowers and. Mar 10, 2014 organisms play a significant role in the deterioration of concrete. Design, durability and performance comprehensively examines structures located in, under, or in close proximity to the sea. Over the past 20 years, corrosion testing on concrete structures has been used increasingly for monitoring deterioration as well as for defining the areas in need of repair. Where mass concrete is relatively free to expand in all. While this is a positive change, often the quality and the rationale behind the testing are not sufficiently well defined. Strategy for new marine structures preventive maintenance strategy 1. Case studies of concrete deterioration in a marine environment in portugal. Chapter 5 environmental deterioration of concrete wit press.
Because not only japan but also many countries are plagued by aged. For example, this strategy may apply to structures of longer life than the intended service period by using concrete structures with reinforcing bars of anticorrosion steel for example, stainless steel or epoxycoated steel. Repair terminology causes of concrete deterioration. The prediction of deterioration in marine concrete structures is a major challenge that will still require much research input. Damage to concrete structures with gypsumcontaminated aggregate occurs frequently. A typical example is the prediction of combined transport and deterioration mechanisms in both cracked and uncracked concretes. In order to delay the ingress of chlorides, such structures require the use of thick, dense concrete covers and strict crack width limitations. Durability of marine concrete in libya field study on. Therefore, in this study, the effects of using different quantities of gypsumcontaminated aggregate on the expansion and compressive strength of concrete were investigated over a period of one year. Durability of marine concrete in libya field study on five. Case studies of concrete deterioration in a marine environment in portugal article pdf available in cement and concrete composites 241. A wide range of marine concrete structure types has been presented in this chapter, covering the range of techniques that have been commonly used since the start of port and coastal construction in south africa and abroad.
367 493 214 738 337 1048 353 1285 867 431 603 1184 1154 1237 359 465 1478 978 388 366 1151 1478 749 1160 1056 113 441 558 823 1150 390 252 1138 708 735 1023 1160 1179 600