Nine concrete mixtures with different values of yield stress and plastic viscosity were tested in a concrete truck. Workability is a vital property of concrete and related with compaction as well as strength. Pdf study of workability of fresh concrete using high. The temperature and relative humidity also affect the result. It is used conveniently as a control test and gives an indication of the uniformity of the concrete from batch to. Workability of concrete factors affecting workability of. Fresh concrete consistency workability rheology cone penetration. Strictly, it is the amount of useful internal work necessary to produce 100% compaction. Factors affecting workability of concrete civil engineering. A workable concrete should possess following two requirements.
Compaction factor test of concrete for low workability concrete. Measurement of workability of fresh concrete using a. Effect of superplasticizers on workability of fresh concrete. Another similar term used to describe a freshly prepared concrete is consistency which is the. Workability depends on the batching in fine elements, quantity of water, temperature, batching in cement and so on. As the name suggests, in this test the workability of concrete is determined by examining the flowing property of concrete. Ifif meticulousmeticulous carecare isis notnot exercised,exercised, andand goodgood. Use of aggregates which are round and have smooth surfaces increases the workability. Important to the workability of fresh concrete the grading or particle size distribution of an aggregate is determined by sieve analysis. The higher the water content per cubic meter of concrete, the higher will be the fluidity of concrete, which affect the workability.
Summary of concrete workability test methods the university of. Cement and water contents in relation to maximum size of aggregates, for air. Sampling concrete mix m15 is blended according to the specified mix design in the laboratory. Workability of concrete is a broad and subjective term describing how easily freshly mixed concrete can be mixed, placed, consolidated and finished with minimal loss of homogeneity. Workability is a property that directly impacts strength, quality, appearance, and even the cost of labor for placement and finishing operations. Indeed, the slump test has remained the standard tool throughout the world for characterizing the workability of freshly mixed concrete because of the devices. Slump test suitability this method is suitable only for the concrete of high workability. Concrete workability, high performance concrete, slump, compacting factor, vebe time, viscosity. Apr 30, 2016 workability of concrete is defined as the ease and homogeneity with which a freshly mixed concrete or mortar can be mixed, placed, compacted and finished. Workability of fresh concrete by compacting factor test. Measurement of workability of fresh concrete using a mixing truck. Properties of fresh concrete with pdf file engineering. Determination of workability of fresh concrete by veebee consistometer theory.
Slump test doesnt give accurate results for the low workability of concrete when the slump is no slump, if it has a slump less than 2 cm and a vebe time longer than 5 sec. Workability is the ability of a fresh plastic concrete mix to fill the formmold properly with the desired work pouring, pumping, spreading, tamping, vibration and without reducing the concrete s quality. Workability of concrete factors affecting workability. Workability of concrete is the property of freshly mixed concrete which determines the ease and homogeneity with which it can be mixed, placed, consolidated and finished as defined by aci standard 116r90 aci 1990b. It is not a suitable method for very wet or very dry concrete. The slump value of a superplasticized concrete may also be affected on account of other admixtures used concurrently in concrete such as airentraining agent, fly ash, slag or silica fume. Study of workability of fresh concrete using high range. There is also the effect of type of cement or characteristics of cement on the workability of concrete. The slump test is the most common method for assessing the flow properties of fresh concrete.
Workability of concrete is defined as the ease and homogeneity with which a freshly mixed concrete or mortar can be mixed, placed, compacted and finished. Flow table test of concrete also determines the quality of concrete concerning its consistency, cohesiveness and the proneness to segregation. Let us discuss these properties of fresh concrete and tests to performed on it. Workability, in the simplest language, is the ease with which freshly prepared concrete can be transported and placed for the job and compacted to a dense mass the fresh concrete which may be expected to give the best results must possess the property of workability. Flow table test of concrete to test workability of concrete. Workability of concrete types and effects on concrete. Properties of fresh concrete workability fresh concrete is a mixture of water, cement. Workability of fresh concrete the strict definition of workability is the amount of useful internal work necessary to produce full compaction. Slump test is the most commonly used method of measuring consistency or workability of fresh concrete which can be employed either in laboratory or at the site of work. Workability is the ability of a fresh plastic concrete mix to fill the formmold properly with the desired work pouring, pumping, spreading, tamping, vibration and without reducing the concretes quality. It determines the time required for transforming, by vibration, a concrete specimen in the shape of a conical frustum into a cylinder. Since the early 20th century, the concrete industry has recognized the need to monitor concrete workability to ensure that concrete can be properly placed and can achieve adequate hardened strength.
Higher workability concretes are easier to place and handle but obtaining higher workability by increasing water content decreases strength and durability. The use of highly fluid concretes, the rheology of which cannot be suitably characterized with the slump test astm c 143 1 alone, has resulted in the emer. It is vital, therefore, that the consistency of the mix be such that the concrete can be transported, placed, and finished sufficiently early enough to attain the expected strength and durability. Workability of concrete is a broad and subjective term describing how easily freshly mixed concrete can be mixed, placed, consolidated, and finished with minimal loss of homogeneity. Procedure to determine workability of fresh concrete by slump test. The report discusses the factors affecting the performance of fresh concrete and provides a better understanding of the issues related to the design of workable concrete, from no flow zeroslump to flow like a liquid selfconsolidating concrete. Design and construction of garden combining small aquarium miniatures from cement, bricks and old duration. Slump test compaction factor test veebee consistometer test 1. The useful internal work is a physical property of concrete and is the work or energy required to overcome the internal friction between the individual particles of the mixture. Compaction factor test of concrete for low workability. Slump test is used to determine the workability of fresh concrete.
The potential strength and durability of concrete of a given mix proportion is very dependent on the degree of its compaction. Oct 29, 2015 different test methods for workability measurement depending upon the water cement ratio in the concrete mix, the workability may be determined by the following three methods. Workability is a property that directly impacts strength, quality, appearance, and. The fresh concrete is usually considered as a nonnewtonian fluid since it is a mixture of aggregate, cement and water.
Fresh concrete should be capable of spreading uniformly without inducing any segregation of the aggregates. Estimating concrete workability based on slump test with least. Workability can be defined as the property of fresh concrete which describes the ease and homogeneity of the concrete to be mixed, fully compacted and finished. Mar 25, 2018 design and construction of garden combining small aquarium miniatures from cement, bricks and old duration. This is the most important property of fresh concrete. Process of manufacture of concreteprocess of manufacture of concrete itit isis interestinginteresting toto notenote thatthat thethe ingredientsingredients ofof goodgood concreteconcrete andand badbad concreteconcrete areare thethe same. Unworkable concrete needs more work or effort to be compacted in place, also. Coarseness workability consolidation a new approach. Workability of concrete types and effects on concrete strength. Abstract this study is directed to evaluate the ability of using cone penetration test as a.
What are the factors affecting workability of concrete. Workability is a property of raw or fresh concrete mixture. Fresh concrete is generally considered low workability no. Procedure to determine workability of fresh concrete by compacting factor test. There are many supplementary materials used for improving quality of fresh concrete. Workability of concrete is measured in terms of the ease of mixing and placing of concrete. Common workability tests are the slump test, compaction factor test, flow test, vebe test, and other field tests like the kelly ball test, and the ktester probe. Properties of fresh concrete controls long term behavior of the concrete.
Concrete is said to be workable when it is easily placed and compacted homogeneously i. It is important to perform some tests on fresh concrete in order to have desired long term results. The main objective of this study is to evaluate the workability of fresh portland cement concrete while it is still in the mixing truck by determining fundamental rheological parameters plastic viscosity and yield stress. Enhancement of workability of cementpoor concrete by. Workability is the ability of a fresh plastic concrete mix to fill the formmold properly with the desired work vibration and without reducing the concrete s quality. Factors affecting workability of concrete a concrete is said to be workable if it is easily transported, placed, compacted and finished without any segregation.
Pdf report of rilem technical committee tc145 wsm workability of special concrete mixes find, read and cite all the research you need on. Apr 04, 2014 factors affecting workability of concrete a concrete is said to be workable if it is easily transported, placed, compacted and finished without any segregation. Properties of fresh concrete include workability, air content, temperature and setting time. The compacting factor test is performed to find out the workability of concrete. The factors that affect the workability of concrete are given below. To assess the workability of concrete using compaction factor test apparatus compaction factor apparatus trowels hand scoop 15.
Workability is a property of freshly mixed concrete, and a concrete is a mixture of ce. Fresh concrete is generally considered low workability no slump, if it has a slump less than 2 cm and a vebe time longer than 5 sec. This video animation, animated video explains the procedure for determination of workability by compaction factor test. The apparatus used for doing slump test are slump cone and tamping rod. It does not measure all factors contributing to workability, nor it is always representative of.
Astm defines it as that property determining the effort required to manipulate a freshly mixed quantity of concrete with. It is easy to work with a highly workable concrete as it can be easily mixed, transported, placed and compacted. The slump test is the most widelyused method of measuring the workability of fresh. Feb 01, 2005 the main objective of this study is to evaluate the workability of fresh portland cement concrete while it is still in the mixing truck by determining fundamental rheological parameters plastic viscosity and yield stress. One of the problems found in workability is occurence of segregation depending on wc ratio. Slump test doesnt give accurate results for the low workability of concrete when the slump is jan 25, 2017 objective. Study of workability of fresh concrete using high range water. Due to this all the properties of concrete, whether in fresh. Highly workable concrete can easily be mixed, placed and transported. For high strength concrete, as low wc is to be maintained, the workability should be achieved by use of admixtures, such as water reducers and airentrainers. All the materials and processes involved in producing concrete affect the workability of concrete.
Workability of concrete and compaction factor test. Watercement ratio is one of the most important factor which influence the concrete workability. Workability is one of the physical parameters of concrete which affects the strength and durability as well as the cost of labor and appearance of the finished product. Evaluation of consistency properties of freshly mixed concrete. Pdf study of workability of fresh concrete using high range.
Concrete, paste content, workability, talc, void volume. Common workability tests are the slump test, compaction factor test, flow test, vebe test, and other field tests like the kelly ball test, and the k. Properties of concrete workability, setting, bleeding. To achieve this, a slump test, compacting factor test and. This study describes the performance of concrete in fresh state, intended for sealing deep bore. A myriad of test procedures for determining workability have been developed for research, mix proportioning, and field use. Workability is most often assessed through the slump test aashto t 119, with a desired range in slump for eot concrete often specified between 50 and 150 mm 2 to 6 in. To determine the workability of concrete by using veebee consistometer as per is. Following are the important properties of fresh concrete. In simple words, workability means the ease of placement and workable concrete means the concrete which can be placed and can be compacted easily without any segregation. It is the amount of work required to place concrete and to compact it thoroughly workability of concrete increases with the addition of water but it reduces the strength and as such it is not a very desirable way of increasing the workability. Pdf workability is one of the physical parameters of concrete which affects strength and durability as well as cost of labour and appearance of.
Workability is the ability of a fresh plastic concrete mix to fill the formmold properly with the desired work vibration and without reducing the concretes quality. The ability of fresh concrete to fill the various shaped form is called workability of concrete. Workability depends on water content, aggregate shape and size distribution, cementitious content and age level of hydration and can. Some of these, like fly ash, improve workability and some of these like steel or synthetic fibers decrease workability. High workability will cause segregation in concrete. The ease with which the concrete ingredients can be mixed, transported, placed, compacted, and finished with minimum homogeneity loss. Workability of concrete civil engineering community.
The fresh concrete which may be expected to give the best results must possess the property of workability. Therefore it consists of a stiff mass that has to be compacted by means of pressure combined with vibration, rolling andor extrusion. Pdf predicting the workability of fresh concrete using simple. Different test methods for workability measurement depending upon the water cement ratio in the concrete mix, the workability may be determined by the following three methods. Water content will have important influences on the workability in given volume of concrete. The main issue in working with fresh concrete is the workability during filling of formwork. Fresh concrete stiffens with time and loss workability though it is not exactly settling or getting strength at all. Higher the watercement ratio, higher will be the water content per volume of concrete and concrete will be more workable.
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