Workability of Concrete

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A Review on Factors Affecting Workability of Concrete

A Review on Factors Affecting Workability of Concrete

Cristian Druta (2003) carried out an experimental study on to compare the Splitting Tensile Strength and Compressive Strength values of self-compacting and normal concrete specimens and to examine the bonding between the coarse aggregate and the cement paste using the Scanning Electron Microscope. In this experiment used mineral admixes Blast Furnace Slag, Fly Ash and Silica Fume and chemical admixes Super plasticizers and Viscosity-Modifying Admixtures, It has been verified, by using the slump flow and U-tube tests, that self-compacting concrete (SCC) achieved consistency and self-compatibility under its own weight, without any external vibration or compaction. Also, because of the special admixtures used, SCC has achieved a density between 2400 and 2500 kg/m3, which was greater than that of normal concrete, 2370-2321 kg/m3.Self-compacting concrete can be obtained in such a way, by adding chemical and mineral admixtures, so that its splitting tensile and compressive strengths are higher than those of normal vibrated concrete. An average increase in compressive strength of 60% has been obtained for SCC, whereas 30% was the increase in splitting tensile strength. Also, due to the use of chemical and mineral admixtures, self-compacting concrete has shown smaller interface micro cracks than normal concrete, fact which led to a better bonding between aggregate and cement paste and to an increase in splitting tensile and compressive strengths. A measure of the better bonding was the greater percentage of the fractured aggregate in SCC (20-25%) compared to the 10% for normal concrete. [9] Subramanian and Chattopadhyay (2002) are research and development engineers at the ECC Division of Larsen & Toubro Ltd (L&T), Chennai, India. They have over 10 years of experience on development of self-compacting concrete, underwater concrete with ant wash out admixtures and proportioning of special concrete mixtures. Their research was concentrated on several trials carried out to arrive at an approximate mix proportion of self-compacting concrete, which would give the procedure for the selection of a viscosity modifying agent, a compatible super plasticizer and the determination of their dosages. The Portland cement was partially replaced with fly ash and blast furnace slag, in the same percentages as Ozawa (1989) has done before and the maximum coarse aggregate size did not Exceed. The two researchers were trying to determine different course and fine aggregate contents from those developed by Okamura. The coarse aggregate content was varied, along with water-powder (cement, fly ash and slag) ratio, being 50%, 48% and 46% of the solid volume. The U-tube trials were repeated for different water-powder ratios ranging from 0.3 to 0.7 in steps of 0.10.

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EFFECT OF CRUMB RUBBER ON WORKABILITY OF GEOPOLYMER CONCRETE

EFFECT OF CRUMB RUBBER ON WORKABILITY OF GEOPOLYMER CONCRETE

To determine the workability of concrete mix by slump test conducted by as per IS 1199-1959. The internal surface of the mould thoroughly cleaned and freed from superfluous moisture than mould placed on a smooth, horizontal, rigid and nonabsorbent surface. The mould was filled in four layers, each approximately one-quarter of the height of the mould. Each layer was tamped with twenty-five strokes of the rounded end of the tamping rod. The bottom layer tamped throughout its depth. After the top layer has been rodded, the concrete was struck off level with a trowel or the tamping rod, so that the mould is exactly filled. The mould removed from the concrete immediately by raising it slowly and carefully in a vertical direction. This allows the concrete to subside and the slump shall be measured immediately by determining the difference between the height of the mould and that of the highest point of the specimen being tested.

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Glass Waste in Concrete: Effect on Workability and Compressive Strength

Glass Waste in Concrete: Effect on Workability and Compressive Strength

Workability is property of concrete which determine ease in mixing, placing and compaction of concrete. The results of workability in terms of slump for concrete made using waste glass as cement and fine aggregate replacement are shown in table 3 and 4. The same results are given in figure 4 and 5 for visual observation and having the idea about variation pattern. It was observed that at constant dose of Superplasticizer (0.6%) workability of concrete made using waste glass as cement replacement was increased with replacement level. This increase was due to the increasing content of waste glass with is hydrophobic in nature. Resulting is more availability of water as compare to conventional concrete. It was also observed that workability of concrete made using waste glass as fine aggregate replacement was increased with replacement level up to 40% and there after reduction in slump was observed. Increase in workability may be due to the non water absorbent nature of waste glass as compare to natural sand. However decrease in slump may be due to the loss of effective water from specimen through rapid transportation caused by more voids produced by equivalent waste glass component in lieu of natural sand being heavier than the later.

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EFFECT OF RECYCLED COARSE AGGREGATE ON WORKABILITY ON GEOPOLYMER CONCRETE

EFFECT OF RECYCLED COARSE AGGREGATE ON WORKABILITY ON GEOPOLYMER CONCRETE

Available Online at www.ijpret.com 197 replacement percentage is 50. Replacement of coarse aggregates with Recycled Coarse Aggregate will reduce the workability of Concrete. Increase in the percentage of replacement of aggregate will decrease the workability of Geopolymer concrete.

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Behaviour of a New Concrete Composition with Jaggery as Admixture

Behaviour of a New Concrete Composition with Jaggery as Admixture

Abstract: Quality of concrete is influenced by the proportion of ingredients and method of preparation in concrete production. A unique word which is used on concrete is inevitable in human life due to its properties and applications. From the ancient days lime and jiggery are used as binding materials. This review paper expressed the significance of jaggery on strength behavior of a new concrete composition. Experimentation carried out for determining strength properties of a new concrete for M20 grade nominal concrete using jaggery as admixture. Based on previous study, jaggery is an unrefined sugar product and it is easily available market; the main function of jaggery is to increase the initial setting time of concrete and it also influencing the properties of concrete. Preferably this type of admixture is used in different construction sites like deep foundations, piers and long piles. Four different percentages of admixture was chosen into the experimentation at 0, 0.25, 0.50 and 0.75% by weight of cement, finally it is accomplished that the workability of concrete is being superior with jiggery as admixture but flexural strength and shear strength of this new concrete decreased as compared with convectional M20 concrete.

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An Investigation On Mechanical Properties Of Hybrid Fiber Reinforced Concrete

An Investigation On Mechanical Properties Of Hybrid Fiber Reinforced Concrete

In this experimental investigation work is carried out using 2 types of different fibers. They are crimped steel fiber and polypropylene fiber with different mix proportion by volume of concrete is added into mix with replacement of cement by fly ash and silica fume respectively. The work for M30 grade of concrete can be designed according to IS 10262:2009 with three different proportions of fibers and with mineral admixture. The proportion of steel and polypropylene fibers are added are 1% for mono fibers i.e. SF and PPF and hybrid fiber of percentage of (0.5+0.5) % (SF+PPF) with 20% of fly ash and silica fume respectively. The objective is to determine properties of hybrid fiber reinforced concrete with and with different type of mono fibers planned as steel fiber and polypropylene fiber. To find the effect of fly ash and silica fume as replacement of cement with fixed amount of replacement of 20% respectively with different fibers on the strength of concrete. The Strength properties such as compressive strength, split tensile strength and flexural strength after 28 days of curing are studied and compared. From the investigative study the result showed that polypropylene fiber give more workability compared to steel fiber and hybrid fiber and workability of concrete improves with replacement of mineral admixture in concrete and for replacement of cement by silica fume there is good increase compared to fly ash and conventional concrete. The strength of concrete with silica fume was greater with 1% steel fiber but it had low workability. Hybrid fiber with (0.5+0.5) % content showed both better workability and strength in both the parameter with silica fume.

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LIGHT WEIGHT CONCRETE USING EXPANDED PLOYSTRENE BEADS AND PLASTIC BEADS

LIGHT WEIGHT CONCRETE USING EXPANDED PLOYSTRENE BEADS AND PLASTIC BEADS

1) WORKABILITY:- This test is the most commonly used test for determining workability of fresh concrete. This test is done to see that the concerete mixture is not too dry because it becomes difficult to handle and place very dry mixture. Workability of concrete can be measured by Vee- bee consistometer test, slump test and compaction factor test also. Vee- bee consistometer and compaction factor test can be done in laboratory and slump test is used to check workability of concrete at construction site.

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Influence of Rochelle salt on Properties of Concrete

Influence of Rochelle salt on Properties of Concrete

There are many failures of concrete structures in the recent times and upon investigation it has been concluded that if small structural disintegrities have been checked on time, the failure of those structures can be prevented. This led to very new research field viz, continuous monitoring of the structure. The study of this thesis is mainly focussed on observing the effects of Rochelle salt on properties of concrete such as workability of concrete, compressive strength of concrete and flexural strength of concrete and also to monitor the voltage output, if any, produced by concrete during loading.Different percentages of Rochelle salt will be used as admixture in concrete and the percentage of Rochelle salt at which optimal results are obtained will also be obtained during the research work of the thesis.

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Performance Of The Concrete Containing Waste Glass Powder As Partial Replacement.

Performance Of The Concrete Containing Waste Glass Powder As Partial Replacement.

6) From the above experimental results, considering the strength criteria, the replacement of cement by glass powder is feasible. It is therefore proved that Glass powder can be used as alternative materials in concrete, reducing cement consumption and reducing the cost of construction. Use of industrial waste products saves the environment and conserves natural resources.

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Experimental Study on Self Compacting Concretre by Partial Replacement of Cement with Palm Oil Fuel Ash

Experimental Study on Self Compacting Concretre by Partial Replacement of Cement with Palm Oil Fuel Ash

Self-compacting concrete is a flowing concrete with high workability. To achieve flowing concrete low volume of coarse aggregates is used, but the reduction in volume of coarse aggregates require high volume of paste, i.e. cement and fine aggregates, and use of super-plasticizers. Increased volume of cement and addition of super-plasticizer leads to higher cost. The cost of cement can be reduced by using supplementary cementitious materials. Fly ash, silica fumes and Ground blast- furnace slag has been used in SCC. Malaysia has a high production rate of POFA, and previous studies have been conducted using low volume of POFA as supplementary cementitious material in SCC. This study intends to provide fresh and hardened properties of SCC using high volume of POFA, and determining its practicality.

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Experimental Study on Self Compacting Concretre by Partial Replacement of Cement with Palm Oil Fuel Ash

Experimental Study on Self Compacting Concretre by Partial Replacement of Cement with Palm Oil Fuel Ash

Demand of construction materials are increased now a days. In order to bring down this problem, we are searching for new alternate materials. In the present study, POFA , and Gypsum (SCC) has been used as an admixture to cement in concrete manufacturing and its collection and properties has been studied in phase I. An experimental study will be done to check the strength and workability parameters of POFA concrete used in our project. For normal concrete, mix design is done based on In Standard (IS) method and taking this as reference design, mix design will be carried out for replacement of POFA concrete. The test results derived from SCC concrete will be cross checked with normal concrete and end report will be furnished in phase II.

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A Review on Workability and Strength Behavior of Self Compacted Concrete

A Review on Workability and Strength Behavior of Self Compacted Concrete

Rohan S Gaurav, et al., [7] examined T-Slump test, T500mm Slump test, U-Box test, L-Box Test-Funnel test, V5min test, compressive strength and split tensile strength, water absorption test at7,14 &28 days. In this experimental work, Fine Aggregate replaced with pond ash and quarry dust by 0, 20% and 30%. And from test procedure filling ability and passing ability full filled fresh property ranges of SCC as per “The European Federation of Specialist Construction Chemicals and Concrete Systems” (EFNARC)specifications. Also, compressive strength of SCC is increases with increases of percentage of quarry dust and pond ash, split tensile strength increase with some amount of pond ash and quarry dust after its decreases. At the end of research paper conclusion is, replacement of coarse aggregate by pond ash and quarry dust up to 20% gives good result in good compressive strength and gives good split tensile strength about 3.09 N/mm 2 .

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Effect of Coconut Fiber Ash on Strength Properties of Concrete

Effect of Coconut Fiber Ash on Strength Properties of Concrete

Abstract: This research paper deals with the use of agriculture and industrial waste materials into concrete which enhance the property of concrete and make environment eco-friendly. With the increase in population the cost of cement used in construction is increasing day by day. The increase in demand of cement and need for infrastructural development there is urgent need to focus low cost alternating binding material which can be used solely or in partial replacement of cement. Agricultural waste material, in this case coconut fibre ash, which is an environmental pollutant. Coconut fibres are collected and the fibre are properly dried and burnt in the open air with a temperature range of 600 to 700 . when the fibres turned into ash. The ash was collected and made to pass through 150-micron sieve. This work presents the results of laboratory test carried out using coconut fibre ash (CFA) as a partial replacement for cement in concrete production. Concrete cubes are cast and tested at curing aging 28 days using 0, 5, 10, 15, 20 percent replacement levels. The slump test results show that the workability of the concrete decreased as the CFA content increased & the compressive strength of CFA concrete decrease with increasing the percentage of coconut fibre ash. The percentage strength gained at 28 days for 5% is 18.66 %. The optimum compressive strength of 18.66 N/mm2 was obtained at 5% replacement at 28 days of ages.

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Analysis Of Sulphate Resistance Reactive Powder Concrete With W/C Variations

Analysis Of Sulphate Resistance Reactive Powder Concrete With W/C Variations

www.ijstr.org and 0.23 that is done when soaking 28 day equal to 41.05 MPa and 56 days equal to 34.69 MPa. This is because with the w/c value increasing, the more water content to create pores in the concrete microstructure and the C-S-H compound formed due to the use of silica fume does not work optimally in closing pores from sulfate penetration. The sulfate penetrated into the concrete will react with the C-H compound and flush on the decrease in the compressive strength of the concrete. The optimum w/c value of RPC is 0.20 which produces the highest compressive strength of 71.15 MPa and has the most solid C-S-H structure with the least porosity level when compared to other w/c variations.

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A Review Paper on Recycle Aggregate in Concrete

A Review Paper on Recycle Aggregate in Concrete

Untreated RCA can be applicable as many type of general bulk fill, sub-basement, bank protection, road construction, embankment, noise barriers and also treated RCA can be applicable to new concrete, for shoulders, pavement, side walls, median barriers, gutter and curbs, and foundation dam, bridges. It is also useful in structural grade concrete, lean concrete, base of soil cement pavement, bituminous concrete etc. Numerous remarkable researches have been gone through to prove that recycle coarse aggregate (RCA) could be dependable alternative as aggregate in concrete production. As widely submitted, recycled aggregates are suitable for non-structural concrete implementation and also can be implemented in making of normal structure concrete.

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Performance Assessment of Construction Chemical in Building Construction

Performance Assessment of Construction Chemical in Building Construction

Several distinct types of water reducers are available based on different chemicals although they purport to have a similar function in concrete. They are all organic compounds of high molecular weight, some being synthetic and others derived from natural products.

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An Experimental Study of Flexural Strength of Concrete Beam Reinforced with Fiber Reinforced Polymer

An Experimental Study of Flexural Strength of Concrete Beam Reinforced with Fiber Reinforced Polymer

FRP composites can be manufactured on site using the wet lay-up process in which a dry fabric, made of carbon or glass, is impregnated with epoxy and bonded to prepared concrete substrate. Once cured, the FRP becomes an integral part of the structural element, acting as an externally bonded reinforcing system. FRP composites can also be prefabricated in a manufacturing facility in which the material is pultruded to create different shapes that can be used for strengthening applications, such as rods, bars and plates.

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sand with other materials in concrete production. Such materials have included laterite and quarry dust. Formed as a result of weathering of basalt under humid, tropic condition; laterite is a mixture of clayey iron and aluminum oxides and hydroxides [4] and it is abundantly available in tropical regions including Nigeria. Concrete containing laterites are termed laterized concrete [5]. Research on properties of laterized concrete has yielded positive results. Udoeyo et al [6] investigated properties of concrete with partial and complete replacement of sand with laterite and observed that the workability of the resulting concrete was directly proportional to the percentage of laterite while compressive strength, split tensile strength, flexural strength and water absorption were inversely proportional to the level of sand replacement with laterite. It was however concluded that laterized concrete with 0 to 40% laterite content produces compressive strength of up to 20MPa. Ettu et al [7] studied the suitability of using laterite as the sole fine aggregate in concrete production using several mix proportions. It was reported that a reasonable number of mix compositions produced laterized concrete that met the minimum compressive strength of 25MPa for reinforced concrete as specified by BS 8110: 1997. It

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COMPAIRING STRENGTH OF CONCRETE BY REPLACING SAND WITH THE CRUSHER DUST

COMPAIRING STRENGTH OF CONCRETE BY REPLACING SAND WITH THE CRUSHER DUST

37 All along India, we have been using natural sand. The volume of concrete manufactured in India has not been much, when compared to some advanced countries. The infrastructure development such as express highway projects, power projects and industrial developments have started now. Availability of natural sand is getting depleted and also it is becoming costly. Concrete industry now will have to go for crushed sand or what is called manufactured sand. So far, crushed sand has not been used much in India for the reason that ordinarily crushed sand is flaky. Badly graded rough textured and hence result in production of harsh concrete for the given design parameters. We have been not using super plasticizer widely in our concreting operations to improve the workability of harsh mix. For the last about 4 to 5 years the old methods of manufacturing ordinary crushed sand have been replaced by modern crushers specially designed for producing, cubical, comparatively smooth textured, well graded sand, good enough to replace natural sand.

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Experimental Investigation of Ceramic Waste Concrete using Magnetized Water 

Experimental Investigation of Ceramic Waste Concrete using Magnetized Water 

It is shown in Figures 2 & 3 that the compressive strength of concrete increases with the usage of magnetized water, and this increase in the strength is due to cluster concept of water and also memory of water concept. But when water is exposed to magnetized field, it is observed that the number of water molecules decreases to a smaller amount. As the more water is available for hydration, the more number of cement particles are hydrated, and this result in better quality and density of hydration products of cement. This increase in hydration may lead to increase in the compressive strength of the concrete. This effect results to increase in efficiency of cement used in concrete.

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