The concrete durability has been defined by american concrete institute aci as its resistance to the weathering activities, different chemical attack, scratch and other dilapidation processes and activities. Low unit weight, low permeability, high absorption, better thermoinsulating capacity and excellent durability of lwac are its prominent characteristics. Factors affecting durability of concrete pdf free download as pdf file. Following are the factors that affect the durability of concrete. Durability of concrete, factors and cracks in concrete. Increasing aggregate size increases the strength of the concrete. Attack by a natural or industrial liquids or gases.
Durability of concrete types of durability and factors affecting. Concrete in contact or buried under nonaggressive soilground water. Nowadays opc is widely used and it is the costly ingredient in the production. Factors affecting durability of concrete surfaces transportation. Strength and durability evaluation of recycled aggregate concrete. Durability is the capacity to keep going quite a while without huge disintegration. Durability durability is the ability to last a long time without significant deterioration. This will definitely damages the concrete structure and durability will be reduced. Air voids are on obvious and easily visible example of pores in concrete. In addition to strength of concrete another factor, environmental condition or exposure condition has become an important consideration for durability. This does not mean that they do not contain interconnected network of capillaries, but these capillaries are so fine that. This objective then can be divided into more small objectives by dividing it into the experiment that will be done which are. Traditionally, durability has been addressed in asphalt mixture design and construction through a combination of the following. Durability of concrete factors affecting durability of concrete.
The objective of the research is mainly to check the factors affecting workability of concrete incorporating pfa. Quality control in concrete and durability factors. Therefore, besides building material mechanical properties and the cost, the structural designer also need to focus on the durability of reinforced concrete. Learn durability of concrete, factors affecting durability of concrete and causes of cracks in concrete in simple language with effective explanation. To have a sustainable concrete structure, durability is key. Factors affecting strength and durability of densified. In most cases, if there is any problem with the durability of a concrete structure, it is the corrosion of the steel reinforcing bars that is most likely to be the major cause. Factors affecting the choice of mix proportions compressive strength workability durability,durability decreases with increase in wc ratio higher is the aggressiveness of the environment lower should be the wc ratio strength of paste increases with cement content and decreases with air and water content studies show that, c. Factors affecting strength and durability of concrete made. Effects of reinforced concrete durability factors mainly include corrosion of steel in reinforced.
Vaysburd construction and building materials 1994 vol. To investigate the paste consistency of cement plus pfa. There are many factors that can affect the strength of concrete. Factors that affect cost estimates for concrete construction. It is utilized in the design of prestressed concrete design. Durable concrete will retain its original form, quality, and serviceability when exposed to environment. Use of inappropriate materials, poor construction practices, curing and mix designs, results in concrete structures often showing serious premature deterioration. Factors affecting concrete strength online civilforum. In all chemical and physical processes influencing durability of concrete structures, two factors are dominant. Compressive strength concrete compressive strength is proportional to the strength of cement and concrete. Factors affecting the durability of concrete bridge decks. Due to the use of inappropriate materials, poor construction practices, insufficient curing, andor improper mix designs, many structures show serious premature deterioration.
Durability and permeability of concrete 605 unit5 2. More than 80,000 crores cum of concrete are poured every year. Test results show that slump, curing, and time of finishing are the most important factors affecting the abrasion resis tance of concrete surfaces. Normally, potable water is recommended for making concrete. Durability is the key concretes durability is defined by its ability to resist weathering action and chemical attack, while maintaining the desired engineering properties. Jan 11, 2017 the concrete durability has been defined by american concrete institute aci as its resistance to the weathering activities, different chemical attack, scratch and other dilapidation processes and activities. Factors affecting durability of lightweight concrete and its. The durability of contemporary concrete is discussed in view of changed technology and performance requirements. To investigate the durability of concrete, this study examined fine aggregate composed of different. Improving durability by more careful crack control improving durability by more careful crack control nonstructural cracks. Sep 19, 2014 durability is the key concretes durability is defined by its ability to resist weathering action and chemical attack, while maintaining the desired engineering properties.
Concrete is very weak in tension, it is so weak that the tensile strength of concrete is usually ignored in the design of. Durability of concrete depends upon the following factors. This paper presents results of the durability characteristic properties of. Research on factors affecting reinforced concrete durability. Test methods like astm 1202, standard test method for electrical indication of concretes ability to resist chloride ion penetration monitor the amount of electrical charge passed through cylindrical specimens for six hours. Costs of materials and supplies and the associated shipping charges influence the cost of any concrete construction project. Kaushal kishore, materials engineer, roorkee concrete strength cement like water, aggregates and some times admixtures is one of the ingredient of concrete. The strength of concrete is affected by various factors including its ingredients, environmental factors, postprocesses or works, and so on. Strength and durability evaluation of recycled aggregate.
With low wc ratio the permeability decreases to such a level that these concretes are impervious to water. Efflorescence in concrete occurs due to moisture, which will converts salts into soluble solutions and when it evaporates salts become crystallized on the concrete surface. Factors affecting durability of concrete pdf durability of concrete concrete durability has been defined by the american concrete institute as its resistance to weathering action, chemical nditions, become a critical factor for crack prevention in mass concrete. The volumetric changes of concrete structures due to the loss of moisture by evaporation is known as concrete shrinkage or shrinkage of concrete. These are known as capillary pores with a width ranging between 0. Durability of concrete factor affecting durable concrete gharpedia. What are properties of hardened concretegoverning factors.
Some of the commonly used scms are flyash, silica fume and metakaoline. Factors affecting strength and durability of concrete made with various cements k. Lightweight aggregate concrete lwac has been used extensively for structural applications for many years. The water used in concrete mix also affects the durability of concrete.
Table 3 specification for marine concrete in port works design manual 4. Durability of reinforced concrete structures,theory vs practice. The durability of cement is defined as its ability to resist weathering action, chemical attack, abrasion, or any other process of deterioration. Factors affecting durability of concrete aggregate. What are those factors, lets find outmaterial costs. Reinforced concrete is widely used in building structures. What is concrete shrinkage and what are the factors. A solid material helps the earth by saving assets and decreasing squanders and the. However, due to its corrosion, deterioration loss is more and more outstanding.
Different concretes require different degrees of durability depending on the exposure environment and properties desired. Factors affecting the durability of concrete and the benefits. And the chloride attack is a major durability problem affecting concrete structures in the marine and island environment 9 11. Pdf physical and chemical characteristics affecting the. Sep 16, 20 compressive strength of concrete varies from 10nmm2 to 500nmm2 for ultra high strength concrete 20008000 psi. Factors affecting strength of concrete the constructor. Testing concrete mix to predict durability construction canada. Jan 05, 2015 durability and permeability of concrete 1. Durability is defined as the capability of concrete to resist weathering action, chemical attack and abrasion while maintaining its desired engineering properties. It is generally true that concrete structures need.
What are the factors affecting the durability of concrete. Unharden concreting getting wet is a severe issue in terms of the durability of concrete and continuous periodic wetting and drying due to the rain is not considered as a very highrisk factor affecting durability of concrete. Pdf durability of concrete structures researchgate. Review of factors affecting the durability of repointing mortars for older masonry a h p maurenbrecher 1, k trischuk 2, m z rousseau 3 abstract the selection of repointing mortars for older masonry in the canadian climate is a subject of debate. Durability of concrete factor affecting durable concrete. Mix must be designed to ensure cohesion and prevent segregation and bleeding. It is a timedependent deformation which reduces the volume of concrete without. Durability of concrete, factors and cracks in concrete youtube. When it comes to concrete durability, engineers should not rely solely on specifying a minimum compressive strength, maximum watercement ratio, minimum cementitious content and air entrainment.
Measuring the durability of concrete to determine its longevity in. Durability and permeability of concrete linkedin slideshare. Repointing mortars should be durable, practical in application e. Factors affecting durability of concrete aggregate research. Durability of concrete factors affecting durability of. Critical factors affecting asphalt concrete durability. Ip this investigation examined variables influencing the 28day com pressive strength and socycle salt scaling loss of concretes made with 18 type 10 cements. This is the main dimension of the material which a design engineer is concerned of. The results at 90 days age indicate that joint finish, mix proportions and sand type are significant factors affecting durability. This is a global problem that annually costs public and private sectors worldwide billions of dollars. For asphalt concrete mixtures, durability refers to the ability of the mixture to resist deterioration as it ages. Factors affecting durability of concrete 27th january 2010 14th march 2016 concrete durability has been defined by the american concrete institute as its resistance to weathering action, chemical attack, abrasion and other degradation processes. The definition of lightweight concrete in other counties might slightly be different, for instance, according to norway code the concrete is assumed to be lightweight concrete if its saturated surface dry density is equal or greater than 1800 kgm 3 and its compression strength should not surpass 85 mpa lightweight concrete is produced by blending cement, water, fine aggregate, and.
Traditional concrete is a composite, which is made of aggregate, portland cement and water. It normally refers to the duration or life span of troublefree performance. Durability of concrete may be defined as the ability of concrete to resist weathering action, che. In the united states, quality work resulting in dense impervious concrete was an appropriate response while the use of blastfurnace slag cements met with favor in several european countries. Introduction concrete the man made rock is the most widely used construction material. Pdf factors affecting the quality of concrete containing. Accordingly cement alone is not a building material, it is the concrete which is a. Effectiveness of a densification process to create strong and durable bonding in densified products such as pellets, briquettes, and cubes can be determined by testing the strength i. Pdf the durability of reinforced concrete is influenced by those physical characteristics of concrete that control the diffusion of gases, such as. Following are the factors affecting durability of concrete. Strength and durability evaluation of recycled aggregate concrete sherif yehia, kareem helal, anaam abusharkh, amani zaher, and hiba istaitiyeh received october 9, 2014, accepted april 6, 2015, published online may 14, 2015 abstract. The addition of scm to concrete reduces the heat of hydration and extends the service life in structures by improving both long term durability and strength. Jan 14, 2018 learn durability of concrete, factors affecting durability of concrete and causes of cracks in concrete in simple language with effective explanation.
Durability of reinforced concrete structures,theory vs. This means that the concrete kept at higher temperature will gain strength more quickly than a similar concrete kept at a lower temperature. In addition, both cement type and joint finish interact with sand type. Factors affecting bond between repairing concrete and concrete substrate magda i.
Factors affecting workability of concrete a concrete is said to be workable if it is easily transported, placed, compacted and finished without any segregation. Concrete usually has two varieties of pores, which establish extend of permeability. How the cement type affects the concrete strength and durability. Concrete durability testing kryton international inc. Concrete surfaces sheltered from severe rain or freezing whilst wet. The definition of lightweight concrete in other counties might slightly be different, for instance, according to norway code the concrete is assumed to be lightweight concrete if its saturated surface dry density is equal or greater than 1800 kgm 3 and its compression strength should not surpass 85 mpa. Impairs watertightness of concrete cover to steel and provides an access for aggressive chemicals, affecting durability of concrete. Factors affecting the durability of concrete repair. The ability of concrete to withstand the conditions for which it is designed without deterioration for a long period of years is known as durability. Concrete is very weak in tension, it is so weak that the tensile strength of concrete is usually ignored in the design of reinforced concrete structures. What are the main factors affecting the durability of concrete in. Workability is a property of freshly mixed concrete, and a concrete is a mixture of ce. May, 2018 the strength of concrete is affected by various factors including its ingredients, environmental factors, postprocesses or works, and so on. Low permeability and shrinkage are two performance characteristics of concrete that can.
Concrete surfaces with poor durability have been a problem on some highways in. According to a formula, when the watercement ratio equal, concrete produced by high. Raveling and surface initiated cracking are the primary distresses associated with durability issues. Moisture present in the atmosphere will also affects durability of concrete structures. The rapid chloride permeability rcp test is an electrical test used to estimate the durability of concrete. Factors affecting durability of concrete pdf composite material. Carbonation begins at the concrete surface and slowly penetrates deeper, typically at a rate of about. As the professional manufacturer of concrete mixers and concrete batching plants, we will tell you some factors that affect the quality of concrete. Strength and durability properties of cement mortar and concrete depends upon envionmental condition if cement species are in sea water than ions of salt may replace the calcium or silicate ion. If cement is reduced, then at fixed wc ratio the workability will be reduced leading to inadequate compaction. Durability of concrete types of durability and factors. Most of the general factors affecting concrete durability are captured above but with sea water, attack of chloride and sulphate, including the exposure condition.
The relative quantities of cement, aggregates and water mixed together, control the properties of concrete in wet state as well as in hardened state. Factors affecting durability of concrete pdf composite. The importance of the factors affecting concrete shrinkage. The importance of the factors affecting concrete shrinkage 1 purpose this paper summarises the research on the causes creating shrinkage strains in concrete and thus the likelihood of shrinkage cracking, illustrates the conflicting requirements in the selection of concrete properties and attributes and provides information on the relevance. Testing concrete mix to predict durability construction.
What is concrete strength and what are the factors. Impact of wc ratio on durability there is a tremendous change in the micro structure of concrete made with highwc ratio and lowwc ratio. If the temperature increases the reaction also increases. Water should be free and clean from oils, acids, alkalies, sugar, salts organic materials etc. It appears, therefore, that other factors must be considered as affecting abrasion resistance, and compressive strength alone cannot be used as a criterion for durable concrete. Permeability of concrete factors affecting permeability. Concrete is the most commonused construction material in the modern world. Concrete surfaces protected against weather or aggressive conditions,except those situated in coastal area. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design. If concrete is impervious, or in other words, its permeability is not high then acidic agents and corrosive agents cannot infiltrate and attack it. Factors affecting durability of lightweight concrete and.
Pdf physical and chemical characteristics affecting the durability. Durability aspects of standard concrete m vijaya sekhar reddy1, i v ramana reddy2, k madan mohan reddy3 and c m ravi kumar4 in todays competitive environment it is becoming important to reduce the construction cost in one or other way. The rate of hydration reaction is temperature dependent. Effect of silt fines on the durability properties of concrete. This paper discusses the suitability of producing concrete with 100 % recycled aggregate to meet durability and. Many factors can influence that life span, however poor concrete practices and lowquality materials can cut those lifespans by decades. The mixing of these materials in specified proportions produces concrete.
Rain effect the water cement ratio of the area exposed to wetting. Factors affecting bond between repairing con crete and. Voids in concrete can be filled with air or with water. Factors affecting the durability of concrete and the.
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