Proceedings of the International rilem conference Materials, Systems and Structures in Civil Engineering 2016

89

International RILEM Conference on Materials, Systems and Structures in Civil Engineering 

Conference segment on Service Life of Cement-Based Materials and Structures 

22-24 August 2016, Technical University of Denmark, Lyngby, Denmark 

 

Figure 10: H5 Extrados Tangential prestressing effect 

2.2.3 Strains between end of prestressing and 5.2 bar abs. plateau 

On the following graph 

[Figure 11]

, experimental results are represented by a red horizontal 

line. The experimental results represented in this part are strains corrected from temperature 

effects. Experimental results take into account the effects of pressurization, but also creep and 

shrinkage effects since the end of prestressing. 

Experimental results take into account the effects of pressurization, but also creep and 

shrinkage effects since the end of prestressing. In both directions, experimental results are 

elongation strains.  

In vertical direction, strains are globally well estimated: some teams overestimate elongation 

a little, others underestimate it a little. In tangential direction, strains are globally well 

estimated. 

2.2.4 Stresses evolution results 

For this part, experimental results are not available. Teams’ results are scattered. After 

prestressing, in vertical direction, the results ranged from 3 to 12 MPa of compression taking 

all captors together. In tangential direction, the results ranged from 5 to 15 MPa of 

compression taking all captors together. At 5.2 bar abs., the results show that the wall stays in 

compression. There is a large scattering between results; some teams estimated a compression 

stress inferior to 1 MPa. Team 15 results are very strange for captor H6 IT in tangential 

direction and are not represented on the graph: they show that pressurization leads to much 

more compression (33 MPa) than prestressing. 

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90

International RILEM Conference on Materials, Systems and Structures in Civil Engineering 

Conference segment on Service Life of Cement-Based Materials and Structures 

22-24 August 2016, Technical University of Denmark, Lyngby, Denmark 

 

 

Figure 11: H5 Extrados Tangential strains between end of prestressing and 5.2 bars abs. 

 

2.2.5 Cracking state results 

Eight teams answered this topic. All the results are given in the table 

[Table 4&5]

 below, even 

if some of them are partial. 

Experimental results correspond to the results of the inspection after first pressurization test. 

In this inspection, cracks which had an opening inferior to 0.1mm were not mapped. 

 

Table 4: Inner face cracks total length 

Inner face cracks – Total length (meter) 

Team 

Team 

70 

Team 

50 

Team 

49 

Team 

37 

Team 

23 

Team 

21 

Team 

15 

Team 

14 

Experimental 

results 

Gusset 

0 1.0 0 19.32 

N/A 

0.97 4 N/A 

0 

Hatch 

area N/A 1.5  0  0.00 4.6 2.90  8  N/A 

0 

Cylindrical 

part 

0 1.2 0 6.58 

6.0 

0.79 28 N/A 

0 

Dome 

0 0.0 0 0.00 

0.0 0  8 N/A 

138.07 (precast 

slab forms) 

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91

International RILEM Conference on Materials, Systems and Structures in Civil Engineering 

Conference segment on Service Life of Cement-Based Materials and Structures 

22-24 August 2016, Technical University of Denmark, Lyngby, Denmark 

 

Table 5: Inner face cracks max opening 

Inner face cracks - max opening (millimeter) 

Team 

Team 

70 

Team 

50 

Team 

49 

Team 

37 

Team 

23 

Team 

21 

Team 

15 

Team 

14 

Experimental 

results 

Gusset 

0 0.4 0 0.061 

N/A 

0.12 

N/A 

0.015  0 

Hatch 

area 

N/A 

9.0 0  0 0.1 

0.17 

N/A 

0.04  0 

Cylindrical 

part 

0 0.4 0 0.052 

0.1 

0.12 

N/A 

0.01  0 

Dome  0 0 0 0 0 0 

N/A 

none 0.10 

 

Results (not presented in this paper) are available for outer face and for through cracks. 

Experimental results show only cracks > 0.1 mm in dome inner face, dome outer face and 

gusset outer face. Team results show cracks in hatch area outer face, gusset inner and outer 

faces and in cylindrical part inner and outer faces. All team results show no cracks in the 

dome inner face. Experimental results show that it is in this area that there are most cracks, 

but it is on the precast part of the dome: they don’t reflect the dome mechanical behavior. 

Team 50 overestimates cracks opening, other teams are close to experimental results. 

Team 37 overestimates cracks total length, especially for hatch area outer face, other teams 

globally underestimate it. 

 

2.3 Theme 3: air leakage during the pressurization test 

VeRCoRs mock-up first pressurization test has taken place from November 2nd to November 

6th 2015. The global air leakage has been measured at the end of the 5.2 bar abs. plateau. 

During the pressurization test, at the 5.2 bar abs. plateau, the containment wall has been 

sprayed in order to locate leakage faults and quantify the flow through these defects. 

The theme 3 of this benchmark consists in the prediction of air leakage during the 

pressurization test, at the end of the 5.2 bar abs. plateau. The air leakage flow is expressed in 

Nm

3

/h (Normo m

3

 per hour). The normal volume of a gas (expressed in Nm

3

) is the volume it 

occupies in normal conditions of temperature and pressure: TN = 273.15 K (0°C) and PN = 

1013.25 hPa (102 Pa). 

The global air leakage is 7.7 Nm

3

/h. Only 4.384 Nm

3

/h have been measured during the 

spraying phase of the pressurization test.  

Six teams answer to Theme 3. Their global air leakage results are given in the following table 

[Table 6] with the experimental results: 

 

Table 6: Global air leakage results 

 

Experimental  Team 14  Team 21  Team 23  Team 37  Team 49  Team 50 

Global air leakage 

(Nm

3

/h) 

7.7 42.89 

434 

834 

82.7 

4.2 

13.83 

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