Measurement of workability of fresh concrete using a. Effect of superplasticizer dosage on workability and strength characteristics of concrete. The apparatus for the vebe test is shown in figure 3. The measured slump must be within a set range, or tolerance, from the target slump. It is the concrete phase from time of mixing to end of time concrete surface finished in its final location in the structure concrete operations. Workability is the ease with which concrete can be mixed, transport,place, compacted and finished or it will be referred as ease with which we can work with the concrete. Coarseness workability consolidation a new approach. It is not a suitable method for very wet or very dry concrete. It can also be used as an indicator of an improperly mixed batch. Each and every process and materials involved in concrete mixing affects the workability of concrete. The box test evaluates the response of a concrete mixture to vibration. First, some have used this term to describe the ease with which hma can be worked by hand after being placed on the roadway.
The concrete then flows past simulated reinforcing bars and its depth in the trough is measured in two places. Concrete slump test procedure applications, types, uses and. Unworkable concrete needs more work or effort to be compacted in place, also. Nevertheless, it is not an adequate tool for assessing lowslump concrete workability. There is no test for assessing workability of metals. Based on this literature search and on feedback from government, industry, and academia, criteria for an improved workability test device were developed. What is workability of concrete and what are tests is generally performed at site for its determination. But still, for very stiff and dry concrete, this test is often considered to be a good indicator of workability. It is the most common method for measuring the workability of freshly mixed concrete. This test is performed to check the consistency of freshly made concrete.
Compaction factor test is designed in such a way that it can be used only in laboratory but in some cases, it can be used for field concrete tests. Two other common workability tests are the compaction factor test and the flow table test. Even with the increase in knowledge of concrete rheology, the slump test remains the predominately used test method for measuring concrete workability. Jan 05, 20 after the general description of each category, the test methods are described and critiqued. Increase in temperature brings down strength values and increases ductility.
The use of highly fluid concretes, the rheology of which cannot be suitably characterized with the slump test astm c 143 alone, has resulted in the emergence of many new methods for characterizing the flow of freshly mixed concrete. The past researchers have been underscored the use of chemical admixtures imparts. Water content will have important influences on the workability in given volume of concrete. The cone is placed with the wide end down onto a level, nonabsorptive. Standard test method for the slump of hydraulic cement concrete.
High workability concrete for bored pile construction. Due to the low workability of slipform concrete mixtures, the science of rheology is not strictly applicable for such concrete. Workability can be measured by the concrete slump test, a simple measure of the plasticity of a fresh batch of concrete following the astm c 143 or en 123502 test standards. Then curing of inplaced concrete starts 610 hours after casting. Workability of concrete slump test for example, reinforced concrete construction with high percentage of steel reinforcement, it will be difficult to compact the concrete with vibrators or other equipment. Inspect all materials used in the construction of concrete work at their source, on the job, or both. This research sought to identify an effective field test method for measuring the workability of concrete in general and of highmicrofines concrete in particular. Concrete mix design one of the ultimate aims of studying the various properties of the materials of concrete, plastic concrete and hardened concrete, is to enable a concrete technologist to design a concrete mix for a particular strength and durability. In the compaction factor test, a given volume of concrete undergoes free fall from one hopper to the second, and then into a cylindrical container see figure 4. Properties of fresh concrete with pdf file engineering. A novel workability test method vibrating kelly ball or vkelly test that would quantitatively assess the responsiveness of a dry concrete mixture to vibration, as is desired of a mixture.
Concrete slump test is carried out from batch to batch to check the uniform quality of concrete during construction. Tests for workability of concrete at construction site and its values. The concrete slump test measures the consistency of fresh concrete before it sets. In this test samples of fresh concrete is taken in a metallic cone and compacted by a specified vibrator to an ultimate shape of a flat cylindrical mass. Slump test is the most commonly used method of measuring consistency of concrete which can be employed either in laboratory or at site of work. A simple test to determine workability of asphalt concrete progress report dongre workability test dwt raj dongre dongre laboratory services inc. Various tests for workability of concrete at construction sites 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. As strain rate is increased ductility comes down and workability decreases and vice versa. May 15, 2018 this video animation, animated video explains the procedure for determination of concrete slump test. Ray brown introduction the term workability has been used to describe several properties related to the construction of hot mix asphalt hma. To the contrary, the advent of new socalled highperformance concrete. Concrete that is stiff or dry may be difficult to handle, place, compact, and finish and, if not constructed properly, will not be as strong or durable when finally hardened.
Lab manual of concrete technology sanjay ghodawat group of. Concrete slump test generally concrete slump value is used to find the workability, which indicates watercement ratio, but there are various factors. Concrete is an artificial stone which is obtained after hardening the homogenous mixtures of cement, water, aggregates and sometime admixture andor additive to modify the fresh and hardened concrete. The workability of a concrete mix changes with time due to the hydration of the cement, and loss of moisture.
Slump is normally measured by filling an abrams cone with a sample from a fresh batch of 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. 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. Batch one established the reference slump value for the kistner mix using the standard astm cone test. The concrete technology notes pdf ct notes pdf book starts with the topics covering portland cement, mineral and chemical admixtures, classification of aggregate, factors affecting workability, water cement ratio, compression tests, factors in the choice of mix proportions, light weight aggregates, workability etc. Compaction of concrete is, therefore, a twostage process figure 1. It is more precise and sensitive than the slump test and is particularly useful for concrete mixes of very low workability and normally used when concrete is to be compacted by vibration. Place the slump cone in the sheet metal pot of the consistometer and fill it with fresh concrete as described in the slump test. The use of chemical admixtures in concrete is a common solution to achieve full compaction particularly where reinforcement congestion and shortage of skilled workers. 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. A slump test can be used to measure the workability of concrete. The test devices described in the patent documents listed in table 6 typically only. This test is in use in europe and by some state departments of transportation but does not currently have an astm test method developed.
As the name suggests, in this test the workability of concrete is determined by examining the flowing property of concrete. We hope this blog post on concrete workability and its related test methods has been helpful. Move the glass disc attached to the swivel arm and place it just on top of the. Compaction factor test workability of concrete the. This video animation, animated video explains the procedure for determination of workability by compaction factor test. Chapter 9 standard test procedures tests on concrete may 2001 page 9. We need enough workability to make the concrete place able by the paver but not too. Coarseness workability consolidation a new approach daniel cook, ashkanghaeezadeh, tyler ley, p.
Sep 04, 20 workability of concrete compacting factor test nctel. Tests on concrete workability tests slump cone test, compaction factor test. Vee bee testdefinition and procedure workability of. Slump test is used to determine the workability of fresh concrete. The water content was adjusted to compensate for the dry gravel and sand used in the lab. Workability is a property of raw or fresh concrete mixture. Uniformity of the concrete regarding workability and quality aspects can be assessed from batch to batch by observing the nature in which the concrete slumps. Workability in concrete defines its capacity to be placed, consolidated, and finished without harmful segregation or bleeding. This test requires filling a truncated cone with concrete, removing the cone and measuring the distance the concrete slumps. Followings are the factors affect the workability of concrete. Workability of concrete is a complex property of concrete. 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. Slump test compaction factor test veebee consistometer test 1. The factors that affect the workability of concrete are given below.
Veebee consistometer test, flow table test, strength tests compressive strength. What are the difference between tender and contract documents. Tests on concrete concrete slump test, compression test for. Standing committee on concrete technology annual concrete seminar 2007. As it is important to ensure the concrete mixture suits the specification of materials required that is able to be shaped into desired parts for construction for freshly made concrete, several tests are conducted to determine the workability of concrete. Workability of concrete factors affecting workability of. The slump test is carried out on fresh concrete to determine its workability, which is the ease of placing, consolidating, and finishing freshly mixed concrete. It is performed to check the workability of freshly made concrete, and therefore the ease with which concrete flows.
Workability is a complex property of concrete which is defined as the ease with which it can be mixed, transported and placed in position within a homogenous state. Workability of concrete is mainly affected by consistency i. Finding the workability of concrete involves various parameters as workability depends upon stability, mobility, compactibility, placeability and finishability of concrete. The test is popular due to the simplicity of apparatus used and simple procedure. 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 without segregation and bleeding. Determination of workability test for concrete civil engineering animated videos, civil. Factors that influence the workability of concrete are listed. Properties of highworkability concrete with recycled concrete aggregate by testing o100. 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. Workability is defined as the extent to which a material be. Factors affecting the workability of concrete are materials such as water content, cement concrete, sand and aggregate properties such as size, shape, grading, mix design ratio and use of admixtures. The slump test, astm c143, standard test method for slump of hydrauliccement. Summary of concrete workability test methods the university of.
Cement and concrete technology eciv 3341 second semester 20092010. 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. Compaction factor test of concrete for low workability concrete. In this case, the workability of concrete should be such that the concrete flows to each and every part of the member. Vee bee consistometer test workability of concrete test. The slump test is done to make sure a concrete mix is workable. Pdf report of rilem technical committee tc145 wsm workability of special concrete mixes. Procedure for workability test of concrete vee bee test these are the various steps involved in vee bee test procedure. Another similar term used to describe a freshly prepared concrete is consistency which is the. Use of aggregates which are round and have smooth surfaces increases the workability. Highly workable concrete can easily be mixed, placed and transported. Factors affecting workability of concrete civil engineering. The concrete mix design cmd for qcqa superstructure concrete must produce a workable concrete mixture having properties that will not exceed the maximum andor minimum values defined in the special provision. The compacting factor test has been developed at the road research laboratory in united kingdom.
The compacting factor test is performed to find out the workability of concrete. Additional information on workability and quality of concrete can be obtained by observing the manner in which concrete slumps. Flow table test of concrete to test workability of concrete. Workability of concrete is measured in terms of the ease of mixing and placing of concrete. Each entry for a test method is presented in a standard format, namely. Workability test methods for selfcompacting concrete.
However, the concept of rheological behavior may still be considered useful. See chapter 3 concrete testing workability is affected by. Workability of concrete compacting factor test youtube. Due to this all the properties of concrete, whether in fresh.
Slump test simplest and crudest test fill concrete into frustum of a steel cone in three layers. Calculations to determine moving averages for sandequivalent test a4. Concrete workability, high performance concrete, slump, compacting factor, vebe. Obtain samples for strength tests by the same procedure as for slump or air test. The slump is carried out as per procedures mentioned in astm c143 in the united states, is. Modern concrete production systems have not eliminated the need to monitor concrete workability in the field. Slump test doesnt give accurate results for the low workability of concrete when the slump is workability of concrete a concrete is said to be workable if it is easily transported, placed, compacted and finished without any segregation.
First the aggregate particles are set in motion and slump to fill the form giving a level top surface. All the materials and processes involved in producing concrete affect the workability of concrete. The apparatus used for doing slump test are slump cone and tamping rod. Apr 26, 2018 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 without segregation and bleeding. Mar 24, 2020 slump test procedure is performed to check the workability of concrete. Throughout australia, boral has established concrete testing laboratories staffed by qualified and experienced. Concrete is said to be workable when it is easily placed and compacted homogeneously i. Sampling concrete mix m15 is blended according to the specified mix design in the laboratory. It is important to recognise the two stages in the compaction process because, with vibration.
They comprise batching, mixing, transporting, placing, compacting, surface finishing. Strictly, it is the amount of useful internal work necessary to produce 100% compaction. Compaction of concrete finishing of concrete workability definition. Procedure to determine workability of fresh concrete by slump test. Workability will be fairly improved as the temperature of working is higher. Consistency is a general term to indicate the degree of fluidity or the degree of mobility. To assess the workability of concrete using compaction factor test apparatus compaction factor apparatus trowels hand scoop 15. The higher the water content per cubic meter of concrete, the higher will be the fluidity of concrete, which affect the workability. The compacting factor test is designed primarily for use in the laboratory but it can also be used in the field.
Pdf effect of superplasticizer dosage on workability and. Mix the concrete at agitating speed for all revolutions over 150. Concrete slump test for workability procedure and results. Flow table test of concrete also determines the quality of concrete concerning its consistency, cohesiveness and the proneness to segregation. The slump test is the most widely used test for measuring concrete workability. Pdf properties of highworkability concrete with recycled.
Concrete technology notes pdf ct notes pdf eduhub sw. Slump test suitability this method is suitable only for the concrete of high workability. Calculations to determine moving averages for 112 x 34 in. What are the factors affecting workability of concrete. A synthesis of more than 61 existing test methods for workability characterization found that available devices vary widely in their. Determining the consistency of concrete as 1012, part 3 the slump test.
Workability of concrete and compaction factor test. Tests include slump test, slump test, vb test and compacting factor test. Concrete slump test or slump cone test is to determine the workability or consistency of concrete mix prepared at the laboratory or the construction site during the progress of the work. Physical requirement of aggregates as per european standards pdf.
589 1500 694 1337 731 1018 1461 171 130 226 244 1079 831 1009 103 172 1266 207 31 1504 188 296 1018 1279 1504 379 1314 1143 1326 723 1068 71 396 1482 625 1021 938 436 769 129