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CODE & SUBJECT : DCC 2042 – CONCRETE AND

BRICWORK

TITLE : SLUMP TEST

LECTURER’S NAME : PUAN HUSNA BINTI MAT SALLEH

KELAS : DKA1B

NAME

REGISTRATION NO.

MUHAMAD AKMAL BIN MOHAMAD SHARIF

03DKA16F2030

AINUNYASMINE BINTI HASLAN

03DKA16F2023

NIRANDOAL A/L CHENG

03DKA16F2029

NUR AIDA BINTI ZAINOL ABIDIN

03DKA16F2027

OBJECTIVE

To determine the workability or consistency of concrete mix prepared at the laboratory

or the construction site during the progress of the work. Concrete slump test is carried

out from batch to batch to check the uniform quality of concrete during construction.

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THEORY

Concrete is a mixture of sand and rock or similar inert material ( aggregates ) held

together by a cementing material. Usually the cementing material is Portland cement,

but sometimes binders such as asphalt or gypsum are used, in which case the concrete

may be called asphaltic concrete or gypsum concrete.

Properties of concrete are governed not only by the properties of its ingredients (

cement, water, sand, and coarse aggregate ) but also, to a great extent, by the relative

proportions of these ingredients. The proportions must be so selected as to produce a

concrete mixture of desired workability, strength, durability, and economy.

The most common aggregates are crushed stone, although cinders, blast – furnace

slag, burned shale, crushed brick, or other materials may be used because of

availability, or to alter such characteristics of the concrete such as workability, density,

appearance, or conductivity of heat or sound.

Slump is a relative measurement in concrete consistency. It is not an indicator of quality

of the material. The slump of a mix with the same aggregate, cement and water can

vary significantly by adding an admixture. The admixture does not reduce the quality of

the material.

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EQUIPMENT / APPARATUS / ROW MATERIAL

Iron Pan

Trowel

Slump Cone

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Tamping Rod ( 12 mm Diameter)

Measuring cylinder

Base

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PROCEDURE

STEP 1: SAMPLE PREPARATION

1. The quantity of concrete produced based on ratio of 1 : 2 : 4 which means 4 pail

of course aggregate, 2 pail of fine aggregate and 1 pail of cement.

2. The aggregates were in laboratory dry condition. Adjustment was made to the

concrete mix proportion to allow for adsorption of mix water by aggregates.

1. The pan and paddles were lightly moisturized.

2. Those material were added in order;

Coarse aggregate

Fine aggregate

Cement

3. The materials were mixed with 1000ml of water until the mixed blend well.

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3. The cement was spread evenly over the aggregates and continued mixed

4. 10. For ensuring homogeneity, the material was mixed by hand

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STEP 2 : TESTING

1. Clean the internal surface of the mould and apply oil.

2. Place the mould on a smooth horizontal non- porous base plate.

3. Fill the mould with the prepared concrete mix in 3 approximately equal layers.

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4. Tamp each layer with 25 strokes of the rounded end of the tamping rod in a

uniform manner over the cross section of the mould. For the subsequent layers,

the tamping should penetrate into the underlying layer.

5. Remove the excess concrete and level the surface with a trowel.

6. Clean away the mortar or water leaked out between the mould and the base

plate.

7. Raise the mould from the concrete immediately and slowly in vertical direction.

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8. Measure the slump as the difference between the height of the mould and that of

height point of the specimen being tested.

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RESULTS

Slump for the given sample is 50mm and the shape of the concrete slump is true slump.

DISCUSSION

From the performed experiment we came to know that our mean slump value was 50mm

which describes that it is True Slump and its workability is medium.The slumped concrete

takes various shapes and according to the profile of slumped concrete, the slump is

termed as true slump, shear slump or collapse slump. If a shear or collapse slump is

achieved, a fresh sample should be taken and the test repeated. A collapse slump is an

indication that the mix is too wet. A change in slump height would demonstrate an

undesired change in the ratio of the concrete ingredients; the proportions of the

ingredients are then adjusted to keep a concrete batch consistent. This homogeneity

improves the quality and structural integrity of the cured concrete.

Only a true slump is of any use in the test. A collapse slump will generally mean that the

mix is too wet or that it is a high workability mix, for which the slump test is not

appropriate. Very dry mixes having slump 0 – 25 mm are typically used in road making,

low workability mixes having slump 10 – 40 mm are typically used for foundations with

light reinforcement, medium workability mixes with slump 50 – 90 mm, are typically

used for normal reinforced concrete placed with vibration, high workability concrete with

slump > 100 mm is typically used where reinforcing has tight spacing, and/or the

concrete has to flow a great distance.

Limitations of the slump test

The slump test is suitable for slumps of medium to high workabiity, slump in the range

of 5 – 260 mm, the test fails to determine the difference in workability in stiff mixes

which have zero slump, or for wet mixes that give a collapse slump. It is limited to

concrete formed of aggregates of less than 38 mm (1.5 inch).

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CONCLUSION

The concrete slump test measures the consistency of fresh concrete before it sets. It is

performed to check the workability of freshly made concrete, and therefore the ease

with which concrete flows. It can also be used as an indicator of an improperly mixed

batch. The test is popular due to the simplicity of apparatus used and simple procedure.

The slump test is used to ensure uniformity for different loads of concrete under field

conditions.

A separate test, known as the flow table, or slump-flow, test, is used for concrete that is

too fluid (workable) to be measured using the standard slump test, because the

concrete will not retain its shape when the cone is removed.