INITIAL & FINAL SETTING TIME OF CEMENT

Aim: To determine initial and final setting times of cement.

Apparatus: Vicat’s Apparatus with plunger, needles and stopwatch.

Procedure:

a) Initial Setting Time:

1. Prepare a neat cement paste with 0.85 times the water required to give standard consistency.

2. Start the stopwatch at the instant of addition of water. Fill the Vicat’s mould with above paste completely curve smooth off the surface the mould resting on a non-porous plate.

3. Place the test block under the rod bearing the needle. Lower the needle (G) gently in contact with surface of test block and quickly release. Allow it to penetrate into the test block. Repeat this procedure until the needle fails to piece the block for 5 to 7 mm measured from the bottom of the mould.

4. The period elapsed since adding water is the initial setting time.b) Final Setting Time:

1. The mould is prepared as for the determination of initial setting time2. The cement shall be considered as finally set, when up to applying the attachment

gently to the surface of the test block, the needle makes an impression those on where as the attachment fail to do so.

3. The time elapsed since adding water is called Final Setting time.

Observations and Calculations:1. Initial Setting Time: Weight of cement taken:

Weight of Water taken: Initial Setting Time:

2. Final Setting Time: Initial Setting Time (in hours) = Final Setting Time (in hours) =

Result:1. Initial Setting Time of given cement sample is :2. Final Setting Time of given cement sample is :

1

NORMAL CONSISTENCY OF CEMENT

Aim: To determine the normal consistency of Cement.

Apparatus:

Vicat’s Apparatus with plunger, needles and stopwatch.

Procedure:

1. Prepare a past of weighed quantity of cement with a weighed quantity of water, taking care that time of mixing is between 3 to 5 minutes and shall be compared before any signs of setting become visible the time of gauging shall be counted from the time of adding water to the dry cement, until the commencement of filling mould.

2. Fill the Vicat’s mould with paste, the mould resisting on a non – porous plate and then smooth of the surface of the paste making level with the top of mould.

3. Place the test block in the mould together with the non - porous resting plate under the plunger gently to touch the surface of the test block and quickly allowing it to sink in to the plate

4. The operation should be carried out immediately after filling the mould and at room temperature.

5. Prepare trail pastes with varying percentages of water and test as described above and measure the penetration of the needle. This test is to be carried out until the specified penetration is obtained.

Observations and Calculations:

a) Normal Consistency: Consistency is expressed as percentage of water added by weight of cement and the penetration is expressed in mm.

Weight of Cement taken:

S. No. % of water Initial Readingmm

Final Readingmm

Height not penetratedmm

Result: The Normal Consistency of given Cement sample is :

2

COMPRESSION TEST ON CONCRETE CUBES

Aim: To find the compression strength of the given concrete cubes using the Compression Testing Machine.

Apparatus:1. Compression Testing Machine.2. Concrete Cubes of size 150mm x 150mm x 150mm

Procedure:

1. Fix the upper and lower pressure plates on the lower cross – head and the lower table respectively.

2. The identification marks, size, date of casting and weight of each cube are noted down.

3. Select an appropriate measuring range using arrange adjustor knob placed to the right side of the control panel.

4. Place the specimen on the lower compression plate centrally according to the marking on the compressive plate in order to give the complete cross section of the specimen chance to participate equally in the acceptance of load.

5. Lower the movable cross – head until it touches the upper surfaces of the cube and see that the specimen is tightly held.

6. The left valve us kept in fully closed position and opens the right valve and close it after the lower table is slightly lifted up, now adjust the bad pointer to zero with the adjusting knob.

7. Turn the right control valve slowly to open position until you get a desired loading rate.

8. Keep on increase the load till specimen fails.9. The bads are noted at first crack and final crushing of the specimen the maximum

load pointer shows the maximum capacity of specimen.10. Close the right control valve, take out the broken pieces of the rest piece and then

open the left control valve of bring the piston down.11. The normal practice is to test 3 cubes of concrete from one batch. If any value

varies by more than 15% of the average strength, 3 more cubes of same batch may be tested.

Observations and Tabular Columns: Specimen No : Identification Mark : Weight (kg) : Age in Days :

Load at First Crack (KN) :Load at Crushing (KN) :Ultimate Crushing Strength (N/mm2) :Factor of Safety :

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Working Stress (N/mm2) :Ultimate Compression Strength :Working Stress: (Ultimate Compression Strength) / Factor of Safety

Result:Seven Days Compressive Strength of cube is _________ N/mm2.

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SLUMP CONE TEST

Aim:To determine the workability of given fresh concrete mix by slump cone test.

Apparatus:1. Slump Cone2. Trowel3. Tamping Rod

Procedure:1. Place the fresh concrete mix in the clean slump cone in four equal layers, tamping

each layer 25 times with the tamping rod in a uniform manner over the cross – section. For the second and subsequent layers, the rod should be penetrate in to the under laying layer, during each tamping.

2. Strike off the top of cement concrete flush with the mould with a trowel so that it is exactly filled.

3. Remove the metal cone by raising it slowly and carefully in a vertical direction.4. As soon as the concrete settlement stops, measure the subsidence of concrete in

mm. This subsidence is SLUMP.

Observations and Calculations:

1. Weight of Cement: kg2. Weight of Sand: kg3. Weight of Aggregate: kg4. w/c ratio:

Tabulations:S. NO. w/c ratio Amount of

Water (ml)Initial Reading(cm)

Final Reading(cm)

Slump(cm)

Result:The workability of fresh concrete by slump cone test is studied.

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FLOW TABLE TEST

Aim:To determine the flow of mortar at different water cement ratio’s.

Apparatus:

1. Flow table with mould2. trowel3. Measuring cylinder of 250 cc.4. Mixing Pan5. Scale.

Procedure:

1. 200 gms of given sample of cement was taken in to mixing pan and 600 gms of sand added and mixed for one minute.

2. Water added at ratio ingredients is mixed till color was obtained mixing about 5min.

3. Flow mould was placed on the flow table and mould was filled with mortar in 3 equal layers.

4. The mortar was striked off at the top so as to leave the mould filled completely and the table around the mould was cleaned.

5. The mould was steadily removed by lifting it upwards.6. The handle was rotated 15 times the rate of one rotation per second so as to raise

and drop the table.7. Percentage of flow calculated as: (Final Dia - Initial Dia) / Initial Dia * 1008. The experiment was repeated with water cement ratio from 0.3 to 1.1 in steps.

Observations: 1. Weight of sand taken: Gms. 2. Weight of Cement taken: Gms.

Tabular Columns:S. NO. Water

Cement Ratio

Initial Dia(mm)

Final Dia(mm)

Difference(mm)

% of flow

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Specimen Calculations:

1. Observation No. :2. Water Cement Ratio :3. Initial Dia :4. Final Dia :5. Difference :

% of flow in mortar: (Final Dia - Initial Dia) / Initial Dia * 100

Model Graph:

Result:

The percentage of flow of mortar at w/c ratio ____ is ________.

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BULKING OF SAND BY VOLUME METHOD

Aim:To determine the bulking of fine aggregates and to draw curve between water content and bulking.

Apparatus:1. Balance2. Cylindrical container of 250 ml capacity.3. Metal plate4. Steel Rule5. Owen6. Graduated Cylinder7. Beaker

Procedure:

1. Put sufficient quantity of over dried sand loosely in to the container to about two thirds of the full level of top of sand.

2. Push the steel rule vertically down through the sand out the middle to the bottom and measure the height of sand.

3. Empty the container on to a clean metal tray with out loss of sand.4. Add one percent of water by weight of sand and mix thoroughly by haul.5. Put back the loose sand in to the container with out tamping it.6. Smooth and level the top surface of the moist sand and measure the depth (h) at the

middle with the steel rule.7. Repeat the above procedure with 2,3,4,5 % of moisture of the sample. Fill the bulking

at max and starts dropping automatically to zero.8. Every time a different sample should be used.

Observations and Calculations:

1. Weight of empty container : Gms2. Weight of container with oven dried sand: Gms.3. Weight of Sand: Gms.4. Weight of dry sand: Gms.Tabulations:

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% of water ad by wt. of sand (%)

Ht. of moist sand

h’ (cm)

% of bulking sand

(h’ – h)/h * 100

Model Graph:

Result:

Maximum % of Bulking of Sand is ______ % at water content of ______ %.

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SPECIFIC GRAVITY OF COARSE AGGREGATES

Aim:To determine the specific gravity of coarse aggregates.

Apparatus:1. Container2. Weighing Balance.

Procedure:

1. A container was taken it was weighed by using weighing balance as ‘w1’. Now the container was filled with coarse aggregate by ¾ of total coarse aggregate of the container with aggregate was weighted as ‘w2’.

2. Container with aggregates was filled by water and is weighted as ‘w3’.3. Then the container was clean and filled completely with water and weighted as

‘w4’.4. Then he same process was repeated for another two times.5. the average Specific Gravity gives the Specific Gravity of Coarse Aggregates, the

specific gravity was calculated using formula:

S = (w2 – w1) / (w2 – w1) – (w3 – w4)

Observations and Calculations:

Descriptions: Wt. (in Gms)

1. Wt of container w1 = 2. Wt. of container + aggregates w2 = 3. Wt of container + aggregates + water w3 = 4. Wt. of container + water w4 =

5. Specific Gravity of Coarse Aggregates:

S = (w2 – w1) / (w2 – w1) – (w3 – w4)

6. Wt. of Dry aggregates w4 =

10

7. Wt. of aggregates w3 =

% of water absorption: (w3 – w4) / w4 * 100

Result:1. the Average Specific Gravity of Coarse Aggregates is :2. The Retained Water Absorption of Aggregates is :

AGGREGATE IMPACT VALUE TEST Aim:To determine the Impact Value of road Aggregates.

Apparatus:1. Testing Machine2. Cylindrical Steel Cup3. Metal Hammer4. Cylindrical Metal5. Balance6. Tamping rod

Procedure:Test Sample: It consists of aggregates sized 10 mm to 12.5 mm. The aggregates size should be dried by heating at 1000C – 110 0C for a period of 4 hours and cooled.

1. Since the material through 12.5 mm and 10 mm sieves. The aggregates passing through 12.5 mm sieve and retained on 10mm sieve comprises the test material.

2. Pour the test aggregates to fill about just 1/3 rd depth of measuring cylinder.3. Compact the material by giving 25 gentle blows with the rounded end of tamping

tool.4. Add to more layers in similar manner, so that cylinder is filled.5. Strike off the surplus aggregate.6. Determine the net weight of aggregates to the nearest gram (w1).7. Bring the impact machine to rest with out wedging or packing up on the level

plate, lock or floor. So that it is rigid and hammer guide columns are vertical.8. Fix the cup firmly in position on the base of machine and place whole of the test

sample in it and compact by giving 25 gentle strokes with tamping rod.9. Raise the hammer until its lower face is 380 mm above surface of aggregate

sample in the cup and allow it to fall freely on the aggregate sample. Give 15 such blows at an interval of not less than one second but successive of all.

10. Remove the crushed aggregate from the cup and sieve it through 2.36 mm sieves until no further significant amount passed in one minute. Weigh the fraction passing the sieve to an accuracy of 1gm (w2). Also weigh the fraction retained in the sieve.

The mean of two observations, rounded to nearest whole number is separated as the “Aggregate Impact Value”.

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Observations: Sample 1 Sample 2

1. Total Wt. of dry sample taken (w1 Gms) :2. Wt. of portion passing 2.36 mm sieve (w2 Gms) :

Aggregate Impact Value: (w2 * 100) / w1

Aggregate Impact Mean Value:

Aggregate Impact Value Conclusion

10% Exceptionally Strong

10 – 20 % Strong

20 – 35 % Satisfactory for road surface

> 35% Weak for road surface

Result:Aggregate Impact Value for the given aggregate sample is _______ %.

Conclusion:The average aggregate impact value is ________ %. According to IRC the given

aggregate impact value which is between 20 – 35% which is satisfactory for road surface. Therefore, the given aggregates can be _____________________________.

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COMPACTION FACTOR TEST

Aim: To determine the workability of concrete mix of given proportion by Compaction

Factor Test.

Apparatus:

1. Compaction Factor apparatus.2. trowel3. Graduated cylinder of 1000 ml.4. Weighing Machine5. Tamping rod6. Iron Tray to mix concrete.

Procedure:

1. Grease the inner surface of the hopper and cylinders.2. Fasten the hopper trap doors.3. Find the weight of empty cylinder (w1 kg).4. Take 2.5 kg of cement, 5 kg of sand and mix them thoroughly.5. Fill the upper hopper with freshly mixed concrete gently and carefully with trowel

with out compacting.6. Remove the excess of concrete above the top of the cylinder by a trowel.7. Level up the mix and weigh the cylinder filled with fully compacted concrete (w3

kg).8. Repeat the procedure with water cement ratio of 0.6, 0.65……9. Add 10 kg of 20 mm coarse aggregate to the above mix and add water of 0.55 water

cement ratio by weight to the mix and prepare a homogeneous concrete mix.Observations and Calculations:

Weight of Empty Cylinder w1 = kg.

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S. No. w/c ratio Wt. of partially compacted concrete

Wt. of fully compacted concrete

Compaction factor

Model Graph:

Result:The workability of concrete mix is observed by conducting the compaction factor test.

The maximum compaction factor value is ______ obtained at w/c ratio ______.

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COMPASS SURVEYAim:

To determine the distance between two inaccessible points using compass.

Apparatus:1. Compass with tripod stand.2. Plumb bob3. Tape4. Ranging Rod

Procedure:

1. Select the base line of known distance say AB and set the instrument at station A and set up centre of the instrument accurately.

2. Sight to point P and note down the bearing of AP, sight to point Q and note down bearing as AQ. Similarly sight to point B and note down bearing as AB.

3. Shift the instrument to the point B. Take back sight to A and note down the bearing of BA.

4. Similarly note down the bearings from P and Q ( QP and BQ).5. Calculate the entire angle from the observed bearings.6. Compute distance between two inaccessible points PQ using Sine and Cosine

Rules.

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Instrument at Sight to Bearing

A

P Q B

B

P Q A

Observation and Calculations:

Calculations:

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Result:The distance between two inaccessible points is _________ m.

PLANE TABLE SURVEY RADIATION METHOD

Aim:To calculate area enclosed between the given points using Radiation Method.

Instruments Used:1. Plane Table2. Alidade3. Plumbing Fork4. Plumb bob5. Spirit Level6. Compass

Procedure:1. Select the table at “T” level and transfer the point to the sheet by means of

plumbing fork. Thus setting point “t” represents “T” camp the table.2. Keep the alidades touching T and sight to A draw the ray along. The fiducial edge

of the alidade. Similarly sight different points B, C, D, E etc… and draw the corresponding rays a pin may be inserted at “t” and the alidade may be kept touching the pin with sighting the points.

3. Measure TA, TB, TC, TD, TE etc… in the field and plot their distance to same scale along the corresponding rays, thus getting a, b, c, d, e…

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Diagram:

Calculations:

S = (A+B+C) / 2 A1 = √S(S-A)(S-B)(S-C)

Similarly A2A3A4A5 are to be calculated and final area is found out.

Result:Total Area of ABCD:

A = A1+A2+A3+A4

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TACHEOMETRIC SURVEY:WHEN THE LINE OF SIGHT IS IN

DEPRESSION POSITION, BUT STAFF IS HELD VERTICALLY BY USING STADIA HAIR METHOD.

Aim:To conduct tacheometric survey and find the

1. Distance between instrument and staff stations.2. Reduced Level of Staff Station.

Instruments Used:1. Transit Theodolite2. Levelling Staff3. Arrows4. Tripod Stand.

Procedure:1. Set up the tacheometer at some intermediate point between Benchmark and

instrument station and take back sight at BM and a foresight at the instrument station. Determine the R.L. of instrument station.

2. Set up the tacheometer at the at the instrument station, centre and level it with respect to plate bubble and altitude bubble. Take observation at the BM by holding a levelling staff at the BM.

3. Determine the height on instrument. Orient the tacheometer to the staff station an take 3 readings ton the levelling staff with tacheometer inclined at an angle to horizontal sight.

4. Record the observations clearly in that field book.5. From the field book, calculation the distance the instrument station and R.L of the

station.

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Formula:1. For calculation of distance between the instrument station and RL of station Q:

D = KScos2θ + C cosθFor calculation R.L. of staff station Q: R.L. of Q = R.L. of P + H.I. – Dc – Staff Reading at C. or

R.L. of Q = R.L. of P + H.I. – Dtanθ– Staff Reading at C.

Result:The tacheometer survey was conducted and

1. Distance of Instrument and Staff Stations:2. R.L. of Staff Station:

Instrument Station P

Sight to Staff reading Vertical angle

Distance H.I. R.L. of staff stationTop Middle Bottom

P B.M.

20

Q

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