All posts by sidbaglung

About sidbaglung

I am Siddhartha Sharma. I did my Master in civil engineering in France. Currently I am working for a Enterprise PETIT which is a affiliated company of Vinci-Construction. My running project is a office building of 13600m² area, the project is being executed by two renowned companies together Lainé Delau and PETIT with the budget of 40 000 000 Euros. The project is expected to finish in May 2014.

An introduction to Calibel

Calibel is the board made up of rockwool and plasteboard. It is a single object and it is so easy and faster to workwith. Whenever you need a desired dimension of board you just can cut it as easily as you do for plasterboard.


This product is worthy as it has the fire resistance, sound resistance and thermal resistance. This has the thermal resistance of 2.35 m².K/W.


It just can be stick with the concrete using a adhesive plaster as in the picture below.


Using this kind of product instead of using plasterboard and glasswool lot of time can be saved and also the cost.


laine de verreplaque de plaitre

Air tightness test

When the facade comes to an end a air tightness test must be done to assure that the envelope is closed. As this project is BBC & HQE it has many constraints and for example only the tolerance of 1m3 of air flow for the test done at 4 Pa for the surface of 190m². This test is done in depression. The gas is spread at exterior for the measurements and since the volume is in depression the volume of gas entered in the test room is observed from inside. Because the flow of the wind at 50Pa is noticebale this test is done starting from this point for varying pressure in the difference of 10 Pa that means at 50Pa, 40Pa, 30Pa, 20Pa and 10Pa. The result obtained is extrapolated for 4Pa as required by the french laws to find the volume of air entered in the envelope. However generally in Europe the value at 10Pa is accepted.

Below are some photos of this test.


During explanation of the procedures of test and objective:


From the test done, it is obtained 1.9m3 which is almost double then the target. So the thermal bridge has to be identified in order to treat for efficiency of the building envelope.



















A high volume of air transfer was found across the concrete bloc, concrete blocs are very weak insulator.


Also the reservations for wire are also reasons for the air circulation, so the reservations must be enclosed properly to avoid the air transfer.



As the windows covered maximum of surface areas and a remarkable air transfer is observed from wondows. A treatement has to be done for these windows and test must be done in order to obtain the objective desired (minimum : 1m3 )

Facades implantation

As the objective of project is to gain title of “high quality environmental” and “low energy consummation” there are many constraints since the conception till the end of the project. The façade in this project is of aluminium triple glasses and the blocs made by cement and glass. This facade is done in two phases. In the first phase the aluminium blocs with triple glasses layer is implanted. These blocs are fabricated in the factory and it is placed using the fixing lugs. When the airtight/watertight is done then the blocs made by cement and glass (composite ciment verre; CCV) is implanted. As I explained in the previous topics the medium of implantation of facade is bi-mâts, a motorized platform of work standing in two metallic pillars.


Phase I
In the first phase the prefabricated aluminium blocs are implanted in the fixing lugs prepared for this. The fixing lugs must be on the appropriate height and the escapement between them must be correct as the blocs are prefabricated. The position of those blocs are found by the geometrical lines drawn in the project and the need of the blocs. However a adjusting screw is integrated on the lugs for the simplicity of the adjustment.

The blocs are either implanted by the work platform, nacelle or by using crane.





These blocs are fixed with angles at corners to made airtight and watertight. The small openings are then closed by silicon. windows are then put in place and finishing touch of facades is done.



If the blocs are implanted with accuracy the second phase starts:

Phase II

For the second phase the platform is adjusted to leave enough space to implant CCV shells. These blocs are also prefabricated and implanted in the same way as aluminium blocs. First the fixing lugs are implanted with accuracy and the implantation starts.


The pillars must be isolated to avoid the thermal bridge.

Once the blocs are implanted, the adjust must be done to have the predefined spacing between them. Below are some photos before adjusting.



Once the blocs are properly fixed the curtain is fixed on the openings left for this purpose. Then the finishing touch is given to have the good finishing of the facade.

point supp de fixation


façade Garnier

façade, du pont

Impermeability(Water tightness) test

When the surface is treated for impermeability to be sure that is really impermeable a test of impermeability of water is mandatory. For this purpose the water exit are closed temporarily and the water of sufficient height is put for the test. the filled water is colored with florescence powder in order to verify if the infiltration viewed is from the the surface in test.

Add of florescence for the test:

This water remains for some day and then the control of impermeable is done. In the control the company who treated the surface is present along with the construction company and the member of sub-contractors for garden etc.

If the infiltration is observed then the sub-contractor company who treated the impermeability finds the area of infiltration and it treats the surface.





Then retest is done in the same way with the another florescence color to verify the infiltration. If the surface is impermeable the verbal process of receiving support is delivered to the executing company by the sub-contractor who treats the surface.

Neuilly - Plan mise en eau

click here for the sample of process verbal of support reception

Making of a “Garden”

In this topic I am going to describe how the modern garden is made when there exist a building compartiment underneath. For the plane garden there must be no problem for the level of soil. But in this project we have a discontinous surface as in picture below.


I’l talk later ways to overcome this uncontinuous surface. In order to make the garden firt we applied the DELTERAXX just above the concrete surface already treated for impermeability, this material permits infiltration of water from on side (top) and is impermeable the other side (bottom). The water can go down and flow to the exit point.



Then extruded polystyrene (polystyrène extrudé ) is put on to gain the height of the soil which is quite expensive for quality soil as in the photos:


It is then covered by thin layer partly permeable to leave only the water to infiltrate and to resist the solid materials this is geotextile materials.


Knowing the exact position of plant the two bed of iron bars are kept just below the plant in order to fix the plant with the ground.

image (1)

When all these prepartion are made, the soil is put from above to an predefined height.


In order to hold the trees properly welded two layers of iron bars (square) of dimension 2mX2m are posed where there are plants. Then the plants are planted.



jardin 1



In the construction field when the structural works comes to an end many other works comes in action simultaneously. The main thing among those is impermeability (air-tightness/water-tightness) of the entire structure. It is important because the interior works can be started only when the structure is air-tightness. Otherwise in the extreme cold the materials like plasterboard gets ruined as it cannot resist to low temperature and moisture.

In this project the impermeability is done by bituminous waterproofing which is the mixture of Asphalt and vapor barrier. This starts with a thin layer of enamel (varnish : eng; vernis :fr) of around 2mm thick. This helps to make the good contact between the concrete floor and the the vapor barrier, some millimeter thick bituminous product: elastophrène.

1,vernis Fig: enamel (vernis) , 1st layer

DSCN0951Fig: bituminous product, 2nd layer

When this is done an for the raised concrete structures like for solar pannels etc isolation is done by the rockwool and a layer of elastophrene as shown in the figure.

3,isolant sur relevés 20131119_15420320131119_154230


Till this stage on the floor two layers are already put on. This is followed by the isolation. The structure must be isolated otherwise condensation can take place inside the structure and it can damage the materials. Condensation takes place if there is high difference of temperature in short distance and lack of waterproofing materials. So to avoid calculation is done by taking account of thermal resistance of each materials. In this case of impermeability, a product called EFIGREEN A is used which has the resistance (R) of  4.40m²K/W. As it is width (e) of 0.120m, thermal conductance of this material is, lembda = e/r = 0.027 W/mK.


This value obtained is of the good materials that are currently used in market for low energy consuming buildings.

2, pare vapeur et isolantFig: isolation (EFIGREEN A) , 3rd layer

Once the isolation is on place this is again covered by thin bituminous product called elastophrène.


Fig: Elastophrene , 4th layer

The 25mm of hot asphalt is then poured from above. The impermeability obtained is of the mixed properties of Asphalt and elastophrene.

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Once the asphalt is poured a good finishing is required in the upraised concrete structures and on the edge of the structure as to avoid water penetration. This is done by the same bituminous product as show in the figure.


This will minimize the risk of water penetration in the isolation and in the building. The water penetration cause a big damage as it rest there till winter and it can turn into glace where the volume goes high and many fissures may create on the surface which is sufficient to damage the whole impermeability.

But in some areas impermeability is done without isolation. That means a layer of elastophrene is put just above the layer of enamel and asphalt is poured on. This can be done where there is no risk of condensation. That means if the zone just below is non heated zone like parking, there is no risk of condensation and isolation is not mandatory. In this project this is done in the area of future garden(in fig.) because the level below is parking (non-heated area)

20131218_113709                     20131218_115111


Canadian well/puits canadien(FR)

Canadian well is a geothermal well system which uses earth temperature to heat or to cool a house. Canadian well is known as puits Canadien or also puits provençal in french. The main principal of the canadian well is to absorb earth temperature during summer and supply fresh air to the house and supply the relatively hot air in winter.

This phenomena is shown in the figure below:


puit canadien

The VMC pipes are used to absorb the earth temperature. Earth has the temperature of a range 12-14°c only at some depth. So as to absorb this temperature  pipes must be at least 1.2m.

Puits-canadien tuyau

However this principal can be used for big house using the parallel pipes to absorb maximum earth temperature as shown in the figure below:

Puits-canadien tuyau

How it works:

In summer it absorbs the earth temperature of around 12°c in order to diffuse fresh air to house. In winter the exterior temperature is either negative or far less than 12° and this system is highly efficient as it brings the air negative temperature to 12°c.  As the average temperature for comfort in France is 19°C we don’t need to install big heaters to heat the air of 12°c to 19°c. The free earth energy is absorbed and the consumption of expensive electricity is thus reduced. This system is very useful for the people who have allergy to dust.


In order to absorb maximum earth temperature the pipes must be at least below 1.2m as I said before and the length of the pipes usually used is 40m anyway the longer is better. The air velocity must be very low (2.5m/sec) and the diameter of tube  between 15cm and  60cm. The slope of pipes must be less than 2% to assure the best air flow and the radius of curvature less than 50cm.

The best position of end of the tube can be your garden to absorb a fresh air by the tube as shown in figure:

puits-canadien entree

Security in the construction

Records show that there is high risk in civil engineering projects. Many accidents happen day by day and many people die. To minimize the number of accidents in this field one has to work in security.

After the success of a day of  security last year, vinci-construction decided to celebrate for a week (21/10/2013 – 28/10/2013) this year. Vinci construction aims of descending its frequency rate from 12 to 5 till the next year. In this week before starting the work everybody is asked to present in the gathering and interaction is made on different topics between workers and the managers. And different proposition are made to improve the efficiency of materials used, ways to minimize risk etc.  The main objective of this gathering is to minimize the accident of any type.


To work in security one has to be equipped with individual protection equipments. Individual protection equipments means a security shoes with a metallic toe to protect feet, a safety helmet, glasses, a security jacket, ear protection set and gloves.



In each project of Vinci construction a zone is separated for the circulation inside the project area which is called a “red carpet”. Either the whole circulation is colored in red or the two red parallel lines so as to emphasize the circulation zone. The red color was chosen as it matches with the logo and it is clearly visible. A red carpet is the zone where stocking is strictly prohibited; the public are not allowed to enter the site.


The working place must be surround by security railing otherwise they are not allowed to work.



Realizing the importance of security in the construction projects. Vinci-Construction set it’s slogan “if you don’t choose to work in security you don’t work with us“. Which is very purposeful and which has unique objective that everybody is expected to return his home as he came in morning.

How is building made safe to fire?

Building is always exposed to fire risk. Fire may occur due to electrical malfunction, leakage of combustible materials, daily use of fire etc. Keeping this risk in mind today’s buildings are designed to tackle those problems. Structures are designed with degree of quantitative classification like ½ hour, 3/4 hour, 1h, 1h1/2, 2h, 3h, 4h, 6h etc. This means the structure can hold that much time in order to evacuate the zone. The building norms impose constrain on fire safety. For example EUROCODE (Code of construction for Europe) divides the structure in different types like Residential building, public access building, High building, Installation classified for environmental protection, Basic nuclear installation etc and impose constraints accordingly.

The main aim of the code is to avoid propagation to avoid destructive fire , to facilitate evacuation and to facilitate easy exit to save live. To do so, the building is divided in compartments and each compartment has to have the safety exit. And because when on fire, the electricity is not available autonomy fire exit signals will help to evacuate the zone.

Eurocode also defines the types of construction materials like materials for ceiling (M3 , combustible medium inflammable; fire reaction 21 MJ/m²), wall materials(M2, combustible less inflammable, fire reaction 2 MJ/m²) and similarly for floor materials (M3, incombustible) . To avoid spread of fire in whole structure a fire protection product is applied in the outer surface of concrete as in picture.

product                             fire protection


As I talked above a fire resisting door is mandatory in the corridor which contains metal plate so as to block the fire propagation as in picture.

fire door


In the project I am working for it has more than that. It has a fire sprinkler system. It is a system of an active fire protection consisting of a water supply system which pumps water in case of fire alarm. The water will be stored on the roof and used when necessary. It works on the same way as in irrigation system.

Sprinkler                 firefightingwater


sprin res