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About this project:
The Cabinet, headed by Dr. Mostafa Madbouly, agreed, during the government's meeting,, through video conferencing technology, to activate the provisions of Law No. 17 of 2019 matter of reconciliation in some building violations, and legalizing their conditions to support the recovery of state rights, through several controls This includes submitting a reconciliation application, within the period specified by law, with all required documents and fees attached to it.
Including an engineering technical report confirming that the violation occurred before the law came into effect, that is, before April 2019, by testing a sample of concrete to evaluate the age of the concrete building.
Scope:
- CARBONATION TEST:
Carbonation of concrete is a process by which Carbon di Oxide from the air penetrates into the concrete and reacts with calcium hydro-oxide to form calcium carbonates. Conversion of Ca(OH)2 into CaCO3 by action of CO2 by itself is not reactive. In the presence of moisture, CO2 changes into dilute carbonic acid which attacks the reinforcement and also reduces alkalinity of concrete. In this test Phenolphthalein solution is used as indicator.
This test is most commonly carried out by spraying the indicator on freshly exposed surfaces of concrete extracted from the structure.
Carbonation depth is accessed by using a solution of phenolphthalein indicator that appears pink in contact with alkaline concrete with pH value in excess of 9 when the concrete is not carbonized.
Colourless at lower levels of pH value when concrete is carbonated and the protective layer gets destroyed and the steel is exposed to corrosion.
The age of the concrete is estimated based on the following formula:
y=7.2/(R² (4.6x-1.76)²) C²
Where
Y is age of building in years.
X is water – to – cement ratio.
C is carbonation depth.
R is a constant (R= αβ).
R varies depending on the surface coating on the concrete (β) and whether the concrete has been in external or internal service (α). This formula is contained in the Japanese Construction Ministry publication “Engineering for improving the durability of reinforced concrete structure.” α is 1.7 for indoor concrete and 1.0 for outdoor concrete. β values are shown in table 5.2.
TABLE 5.2 VALUES OF β
| Finished condition |
Indoor |
Outdoor |
| No layer |
1.7 |
1.0 |
| Plaster |
0.79 |
|
| Mortar – Plaster |
0.41 |
|
| Mortar |
0.29 |
0.28 |
| Mortar – Paint |
0.15 |
|
| Tiles |
0.21 |
0.07 |
| Paint |
0.57 |
0.8 |
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