Identification and Comparison of Pathologies Encountered at the Level of Bio-Calcarenites Used in the Monuments of the City of Sala and Rabat in Morocco

Identification and Comparison of Pathologies Encountered at the level of Bio-Calcarenites used in the monuments of the city of Sala and Rabat in Morocco.

Global Heritage Stone Resource: The sustainable way forward General Assembly 2021

European Geosciences Union Siham BELHAJ*, Omaima Essaad Belhaj, Hanane Souidi *National School of Architecture Marrakech,Morocco ([email protected]) Abdelmalek Essaadi University,ERESEN, Tetouan, Morocco ([email protected]) Mohammadia engineering school, mohammed v university, Rabat„ Morocco

2021 1 Introduction Aims Tests & Results Conclusion

➢ Inventory on ➢ X-ray diffraction site test (RDX) ➢ Thin section Ultimate ➢ X-ray under goal of this fluorescence microscope work is to test X = -6,8330340°/ 6°49'58.9224"W identify pathologies in Bio- Y = 34,0070770° / 34°0'25.4772"N S = 7 ha calcarenite rocks used in historical sites Chellah and Borj

Adomoue X=-683231°/6°49'56.6"W Determination of: Y=34,04254°/34°02'33.0"N ➢ resistance to Determination of: H= 9m fragmentation BY ➢ Bulk Density ➢ the ➢ Compressive ➢ wear resistance strength

2021 2 Introduction Aims Tests & Results Conclusion The monument of Chellah is an enormous fortress and Merinid necropolis built on the ruins of the Roman city Sala Colonia and still includes the witnesses of these civilizations, Chellah is located on the left flank of the valley of the Wadi Bouregreg which flows into the Atlantic Ocean and which crosses both the city of Rabat and Sala, this monument has housed since the night of years different civilizations and which are the Phoenicians, the Carthaginians, the Idrissids, the Maghraouids Banou Ifren, the Almoravids and the Merinids.

Borj Sidi Benacher known as Skalla la-kdima among the slaoui. (The old Scala), in the format of a bastion built during the Marinid dynasty under the directives of Sultan Abu Yusuf Yaqub ben Abd al Haqq in front of the marabout of Sidi Benacher on the seafront of the city of Sala, the twin of Rabat.

Borj Adoumoue's squala spread over a floor of approximately 960m², consisting of a circular tower, a rectangular platform and covered rooms. The supporting structure of the Borj works consists of a rubble masonry wall with jambs, arches of the openings and dressed stone pillars. This structure supports traditional wooden floors (Gaizas) or traditional fired brick masonry domes.

2021 3 Introduction Aims Tests & Results ❑ Borj Adomoue degradation inventory Conclusion

2021 4 Introduction Aims Tests & Results ❑ Chellah degradation inventory Conclusion

2021 5 Introduction Aims Tests & Results Conclusion

A1 A1 A2 A2

A1-Under the microscope the merinid stone can be A2-Under the optical microscope, the stone of Borj Admoue described as a foraminiferous packstone, it is a limestone site is a sandy limestone characterized by shallow marine or with 30% of micrite bioclasts altered with some detrital coastal deposits with benthic para-foraminifers a percentage of contributions, in fact it consists of 10% quartz from 50 to quartz of 30% from 300 to 500 μm of sub-form - rounded, the 100 μm in diameter, the cement is micro-sparitic cement is essentially micro-sparitic (calcite grains <10 μm).

6 Introduction Aims Tests & Results Conclusion A1 1% chemical composition of merinid stone 1% 1% 0% 0% 0% 0% 0% 0% The percentage of calcium oxide is too high in the merinidA2 stone and 3% 3% CaO reaches 52% while the clay minerals represent 18%, the loss on ignition P.a.f is estimated at 30% this is due to the strong weathering. 9% SiO2 Al2O3 The alteration of the rock is approved by loss on ignition and observation Fe2O3 under an optical microscope. P2O5 52% The predominant elements in rock are oxygen, calcium and carbon. MgO 30% SrO K2O Na2O Counts D173_x2_DRX8

MnO2 Calcite Calcite 10000 distribution of chemical elements in merinid stone 0% & 2% 0% 0% 0% 1% 1% 0% 0% 0% 2% O 4% quartz 8% Ca C 2500

45% Calcite

Calcite; Quartz $-alpha Quartz Calcite;

Calcite

Calcite Calcite

Si $-alpha Quartz

Calcite

Quartz $-alpha Quartz

Calcite

Calcite Calcite

Fe $-alpha Quartz

Calcite; Quartz $-alpha Quartz Calcite;

Calcite

Calcite; Quartz $-alpha Quartz Calcite;

Calcite

Calcite; Quartz $-alpha Quartz Calcite;

Calcite

Quartz $-alpha Quartz Calcite; Quartz $-alpha Quartz Calcite; 37% Calcite Al 0 P 10 20 30 40 50 60 70 80 Position [°2Theta] 7 Introduction Aims Tests & Results Conclusion

1% chemical composition of Borj Admoue stone A1 1% 1% 0%0%0% 0% 0% 2% 0% 0% As shown under an optical microscope, the Bio-calcarenite stoneA2 of Borj 2% SiO2 3% 3% P.a.f Adoumoue is a sandy limestone of comparable fractions of calcium CaO oxide and silica with the presence of clay minerals characterizing the 5% 30% Al2O3 binder mortar. 8% Fe2O3 Na2O The loss on ignition is 25% attesting to significant deterioration. For the Cl distribution of chemical elements, oxygen represents 48%, calcium 15%, P2O5 20% K2O silica 14%. 25% MgO

Counts SO3 D173_x2_DRX3

3600 Quartz Calcite Calcite & distribution of chemical elements in Borj Adoumoue

1% 1600 stone Quartz quartz 2% 1% 1% 0%0%

O Quartz

3% Calcite Quartz; Quartz

3% Calcite

Calcite

Quartz

Quartz Calcite Ca Calcite

400 Quartz

Quartz Quartz

4% Quartz

Quartz Quartz; Calcite Quartz;

Si Calcite Quartz;

Quartz; Calcite Quartz; Quartz; Calcite Quartz;

7% Quartz 48% C 14% Al 0 10 20 30 40 50 60 70 80

Position [°2Theta] 15% Fe Cl 8 Introduction Aims Tests & Results Conclusion Échantillon weight in Kg Bulk density in t/m3 Compressive strength Rs NM EN 1926

➢ Hight porosity

Rs en MPa load in KN ➢ Hight wear resistance Rock-Chellah 0.4 1.63 9.4 4.1

Rock-Borj Admoue 0.4 1.61 9,4 4.0 ➢ Hight weathering minerals

Echantillon Dry density Wet density Percent absorption% Porosity% ➢ Low density

Rock-Chellah 1.7 1.86 12.7 22

Rock-Borj Admoue 1.8 1.9 13 22

➢ Retain Water

Echantillon Resistance to fragmentation Wear resistance Wear resistance Los Angles Test Micro deval test (6.3/10)% (10/14) % (10/14)% ➢ Degradations and alterations

Bio-Calcarenite marine 60.19 70 49.1

9 Introduction Aims Tests & Results Conclusion The rocks in question in the historic site of Chellah in Rabat and the monument of Borj Adomoue de Sala is the Quaternary coastal Bio-calcarenite rock with marine facies called “Pierre de Sala” or “Sandstone of Rabat” described in the work of Ben Boughaba , 2001 and Al Amrani, 2009, this rock has a density equal to 2, density equal to 1.63 t / m3 and a water absorption rate of 12.7% and porosity of 22% probably comes from the quarry by Al Brahma1 (Ben Boughaba, 2001) This rock outcrops in a dune system with intrusions of bioclasts, lenticulars and lumachelles, parallel to the Atlantic coast over a distance of 40 km with an average thickness of 21 m north of Salé, 12 m in Sidi Bouknadel and 37 m in Mehdia. This Bio-calcarenites is of high porosity, showing relatively low densities and a great capacity to retain water. The high porosity of the rock in question favors the capture and fixation of moisture by physical mechanisms: absorption, vaporization, condensation and capillary migration. Situation map of calcarenite quarries on the Kenitra Rabat axis The Bio-calcarenite rock present on the Chellah and Borj Adomoue Historical Site shows (Ben Boughaba, 2001) a low resistance to fracture and a high wear resistance of the 10/14 mm granular class of around 70 and in the 6.3 granular class / 10 mm of 49 and therefore the rock is easily worn with a high friability of the order of 60 for the granular class 10/14 mm. The high wear resistance can only be explained by the high content of weathering minerals. 2021 10 Identification and Comparison of Pathologies Encountered at the level of Bio-Calcarenites used in the monuments of the city of Sala and Rabat in Morocco. Global Heritage Stone Resource: The sustainable way forward

General Assembly 2021 THANK YOU FOR YOUR ATTENTION

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