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PRACTICAL CLASSES

1- Calendar and groups organisation

Week 4 Week 5 Week 6 Week 7 Week 8

18/08-22/08 25/08-29/08 01/09-05/09 08/09-12/09 15/09-19/09

Monday

11am to 1pm

Class 24

Grp 1 to 6

Wednesday

10am to 12pm

Class 1

Grp 1 to 6

Class 7

Grp 1 to 6

Class 13

Grp 1 to 6

Class 19

Grp 1 to 6

Wednesday

12pm to 2pm

Class 2

Grp 1 to 6

Class 8

Grp 1 to 6

Class 14

Grp 1 to 6

Class 20

Grp 1 to 6

Thursday

10am to 12pm

Class 3

Grp 1 to 6

Class 9

Grp 1 to 6

Class 15

Grp 1 to 6

Class 21

Grp 1 to 6

Thursday

12pm to 2pm

Class 4

Grp 1 to 6

Class 10

Grp 1 to 6

Class 16

Grp 1 to 6

Class 22

Grp 1 to 6

Friday

12pm to 2pm

Class 5

Grp 1 to 6

Class 11

Grp 1 to 6

Class 17

Grp 1 to 6

Class 23

Grp 1 to 6

Friday

2.15pm to 4.15pm

Class 6

Grp 1 to 6

Class 12

Grp 1 to 6

Class 18

Grp 1 to 6

o Each Prac. last for 2 hours

o There are 3 different practice classes, 2 groups per prac.

o All groups need to complete a section of the answer sheet page 9.

o The students need to read the Prac. before going to the laboratory.

o The students have to fill up the take 5 before doing any work.

o At the end of the session the student need to fill the results sheets and return it to the tutor.

SAFETY RULES

Non-compliance with regulations may result in the immediate exclusion of the student halls of Hands.

General rules

• Access to the room: the access to the concrete construction facilities is permitted only during the

scheduled sessions.

• You should never handle instruments if tutor or technician supervisor is not present in the room.

Basic safety rules / Personal Protection / Quality

Wear Personal Protective Equipment in needed (student equipment)

o Gloves (loaned equipment)

o Long sleeves top

o Closed/Covered shoes are required, reinforced shoes is the best

o Hears muff are required when casting concrete (loaned equipment)

Follow the instructions contained in the Protocol - Quality:

o Weigh your components neatly and carefully

o Be sure to clean equipment before and after handling

o Clean up the contaminated material

o Follow the normative protocols proposed

o Traceability: identify your specimens following the established coding

Any incident, even minor injuries have to be reported to the tutors and the technician.

Instructions in case of accident: see end of Prac safety book. In addition, the tutors show at the

beginning of the prac locations billboards containing the instructions in case of an accident.

Work environment

• Fire Safety Kits and medicine: follow the tutor and the safety technician instruction in case of

emergency, safety precautions related to the work environment and in particular the fire evacuation

plans and locations kits medicine will be presented before the prac by the tutor.

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Prac. 1: Concrete Pouring (2 groups, 1 and 2):

The letter in parentheses corresponds to the formulation of concrete implementation team.

Concrete design: in kg for 1 m3 de concrete

Compo Group Cement Water Sand Coarse Aggregate Slump

(cm) Ø10mm Ø20mm

A C1-C9-C11-C16-C17-C21-C22 225 198 743 215 998 6

B C2-C6-C7 375 211 618 212 1081 10

C C3-C8-C13 485 201 579 212 1139 10

D C4-C12-C14-C19-C24 450 254 596 215 1169 4

E C5-C10C15-C18-C20C23 335 203 645 254 1056 8

Examine the concrete mixing plan and read the prac, after complete the take 5, e.g. take 5 minutes to

find 5 possible risks in your prac and list them below:

o

o

o

o

o

Description of the prac:

Calculate the composition of the concrete to make 17 litres of concrete

• Weigh the different components (don’t forget to put plastic gloves on)

o group 1 weight the sand, cement and measure with the beakers the water

o group 2 weight the small coarse aggregate (ø10mm) and the big coarse aggregate

(ø20mm )

• Insert the aggregates in the mixer (sang and coarse aggregates) and start mixing,

• After 1 minute introduce the cement from the top

• Mix for 2 minutes

• Insert the water in the mix slowly control by eye the workability (don’t put all the water in

ones)

• Mix for 1 minute...

• Mix and add water until reaching the consistency targeted,

• Measure the slump cone (3 equal layers, 25 blows per layer)

If the slump is ok (+ or – 20mm from the target) start making the samples, if it’s to low put the

concrete back in the mixer and add some more water

• As soon as the slump is right empty the mixer

• One group needs to Measure the density

o Weight 2 empty moulds

o Fill them in half, then vibrate the samples,

o Complete the other half them vibrate them again,

o Smooth the surface with a trowel.

o Clean the surface of the mould as much as possible then with cloth

o Weight the full samples again, calculate the density and record it in the page 7 table

• Cast concrete samples:

o Pour concrete half way in the standard mould and vibrates it using the vibration table

o Pour the second layer of concrete, and vibrate it again

o Smooth and finish the sample with the trowel

o Clean with a wet coth the outside of the moulds avoid the surface (water is the best way

to remove fresh concrete).

o Label them (see NB below)

o 6 cylindrical specimens need to be done, 2 by 2, 3 per group

o Clean with water all tools used for the mixing

• Complete the answer sheet:

NB: To identify samples write down on a piece of paper and put under every moulds, the class (Cx)-

the formulation’s letter – the week number (Wx)- the day (example: C1-A-W4-We)

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Prac. 2: Aggregates arrangement:

Examine prac area, read the prac and after complete the take 5, e.g. take 5 minutes to find 5 possible

risks in your prac and list them below:

o

o

o

o

o

Data: densities: sand: 2.6 t/m3 (S), small coarse aggregates: 2.6 t/m

3 (a), cement: 3.1 t/m

3.

Work involved:

Measure the a bulk densities of sand-aggregates mixtures following (percentage by weight):

o Group 3 measure : 0% S-100% a, 20% S-80% a, 40% S-60% a

o Group 4 measure : 0% a-100% S, 20% a-80% S, 40% a-60% S

o To do so, each group have a cylinder, a compaction tool, a hammer and a scale

i. Fill up the cylinder in half

ii. Compact it

1. With the hammer hit gently the surface of the cylinder (outside)

2. From the top with the compactor

iii. Fill it up to the top, repeat previous steps

iv. The cylinder need to be exactly full

v. Finally weight it.

o When the measurement are done share your results with the other group.

Calculate the real densities of each of these mixtures

o recall:

1/real of the mix of aggregates=X/real for A + Y/real for B

With:

- X proportion of A

- Y proportion de B

Deduce the intergranular porosity of the mixes

Plot the points on a graph (recall: Intergranular porosity p=1-bulk/real) (page 8)

Measure with a 1 litre container the bulk density of cement.

For the mix that have the lower porosity, calculated the volume of cement that can be

introduce into a volume of 1 m3 of the granular mixture considering that the cement fills all of

the intergranular porosity.

Measure the bulk density of the most compact sand-small coarse aggregate-cement mix.

Calculate the actual density of the mixture and deduce the intergranular porosity.

How much water would fill the residual porosity? Calculate the proportion of each constituent

of the mix as compact as possible (small coarse aggregates, sand, cement and water) to a

volume of 1 cubic meter. Compare this formulation to the one given in prac one.

Complete the answer sheet with the results obtained page 7.

Return the results to the tutor

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Prac. 3: Test the concrete 2 groups:

Work involved:

During this session, students must perform compressive strength tests on specimens on the hardened

concrete indicated by the table below.

Week 4 Week 5 Week 6 Week 7 Week 8

18/08-22/08 25/08-29/08 01/09-05/09 08/09-12/09 15/09-19/09

Monday

11am to 1pm

Group 5

C22-A-W7-Fr

Group 6 C23-E-W7-Fr

Wednesday

10am to 12pm

Group 5 C0-E-W3-Th C1-A-W4-We C11-A-W5-Fr C17-A-W6-Fr

Group 6 C0-C-W3-Th C6-B-W4-Fr C12-D-W5-Fr C14-D-W6-We

Wednesday

12pm to 2pm

Group 5 C0-A-W3-Fr C2-B-W4-We C12-D-W5-Fr C18-E-W6-Fr

Group 6 C0-B-W3-Fr C4-D-W4-Th C10-E-W5-Th C16-A-W6-Th

Thursday

10am to 12pm

Group 5 C0-C-W3-Th C3-C-W4-Th C3-C-W4-Th C0-C-W3-Th

Group 6 C0-A-W3-Fr C7-B-W5-We C13-C-W6-We C9-A-W5-Th

Thursday

12pm to 2pm

Group 5 C0-E-W3-Th C4-D-W4-Th C14-D-W6-We C0-E-W3-Th

Group 6 C0-B-W3-Fr C8-C-W5-We C13-C-W6-We C15-E-W6-Th

Friday

12pm to 2pm

Group 5 C1-A-W4-We C5-E-W4-Fr C5-E-W4-Fr C0-A-W3-Fr

Group 6 C0-D-W2-Fr C4-A-W5-Th C14-D-W6-We C0-B-W3-Fr

Friday

2.15pm to 4.15pm

Group 5 C0-D-W2-Fr C7-B-W5-We C6-B-W4-Fr

Group 6 C1-B-W4-We C10-E-W5-Th C0-D-W2-Fr

Compression tests timetable

Complete the take 5, e.g. take 5 minutes to find 5 possible risks in your pract:

o

o

o

o

o

Take out of the curing bath the designed samples, 6 samples 3 per group, refer to the table

Leave the sample superficially drying

Measure their length and diameters and weight them to deduce their density

Measure the compressive strength performance of each samples (the tutor will make the

demonstration)

Descriptive tests every step in details and explain why we are taking that much precautions

(compressive strength break).

Observe the compressive strength curve

o Explain every stages

o Extract the data from the computer for your report (bring a usb key)

Analyses the broken samples (take pictures),

o Observe the shape of the sample after the test

o How the cracks went through the sample, give an explanation

Complete the answer sheet page 9 and return the sheet to the tutor.

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2- Work requested

Warning: the practical sessions are compulsory: any unjustified absence will be penalized on the

Prac Class (PC) mark.

During the Prac.: perform the manipulations required in accordance with the safety regulations set by

the tutors.

At the end of the session PC:

o Clean the tools/equipment

o Clean the room,

o Gather the materials used during PC,

o Completed the result sheet page 10 and 11 return it to the tutor.

Tests results sheet:

These reports will be given to Tutor at the end of the PC. They will summarize the experiences made

during the session by presenting particular Prac results. They should be properly presented.

Final report:

o It is due 2 weeks after your practical class session

o All Prac results will be gathered and updated on LMS every weeks

o An interpretation of all groups’ results is needed.

o A detailed presentation of the PC performed is needed,

o An explanation of the other PC not performed need to be sum up and the main

scientific concept behind each Prac need to be presented.

o Results of all groups have to be plot and accompanied by an interpretation of the

trends.

o The marks will mainly consider the interpretations and comments from students.

o The final report will necessarily follows the following plan:

- Presentation of the practical class performed,

- Presentation of results obtained, explanations of trends and comparison of

the results obtained by the other groups.

- Summary of the 2 other prac

- Interpretation of the results obtain by all the other groups,

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3- Guide lines for the assignment

1. Guidelines

The report will necessarily follow the following plan:

o Prac. performed

o Other prac.

In the report should include:

o The objectives of manipulations;

o The procedure followed during the prac;

o The measurement results in table form;

o The measurement results as graphs;

o Discussion, comparison and interpretation of results;

o The conclusions.

Be noted:

o The care taken along the prac and on the report is marked;

o The quality measures; calculations (eg averages and standard deviations) need to be

presented

o The rigorous reasoning and interpretations and conclusions of the scientific quality is

required

2. Few additional guidance

(absorption coefficient = 2% for sand and 1% for the coarse aggregates).

o Determine Water effective reports / mass of cement (W / C) for each mixes designs.

o From the strength (KN), calculate the stresses (MPa) and discuss the results.

o From the observation of the surface and the inside of the tested sample comment and

correlate those observation to the strength of the samples.

o To compare your experimental results you can use

- Formula Bolomey (Tutorial on formulation).

- In the absence of other information, take the coefficient K = 0.5

- Calculate the strength using the tutorial and compare with the experimental

results

- For the same mixture and the same maturity, why the compressive strength of

cylindrical specimens are different.

When possible, for each formulation, discuss and draw curve of resistance versus time.

When possible, for each maturity, draw and discuss the strengths depending on the

formulation (compaction aggregate quality or quantity of water...)

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Results sheet (to return to the tutor at the end of the session) Prac 1: Concretes Date: Class and group N˚ :

Mixing date :

Composition Slump (cm) Water added in the mix (kg) Density (kg/m3) Water efficient (L)

Prac 2: Aggregates arrangement

Date: Class and group N˚ :

0% S% a-100 20% S-80% a 40% S-60% a 40% a-60% S 20% a-80% S 0% a% S-100 Cement

Bulk density

Real density

o Intergranular porosity:

o Optimum amount of cement in the most compact mix:

o Optimal composition of 1cubic meter of concrete:

Optimum composition (kg) Cement Water Sand Coarse aggregate

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0 10 20 30 40 50 60 70 80 90 100

a % 100% Sand

100% small coarse aggregates (a)

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Prac 3: Compressive strength Date: Class and group N˚ :

Test date : Time of curing days:

Cylindrical samples

Compression (KN et MPa)