Reconstruction and Restoration of Main Facade and Wooden Ceilings of Hasan Basha Tahir Kuttab & Sabil, Cairo—Egypt

The architectural complexes of Hasan Basha Tahir were suffering from many damages and deformation in different elements as load bearing walls, arches and wooden ceiling. Ground water, salt weathering, air pollution, biological colonization and environmental aspects were the main degradation factors which caused a lot of damage and deterioration phenomena in the complexes. Horizontal and vertical cracks, salts, loss of decorations, and featured dark of the stone surface were noticed at the complexes elements. In addition, the celling of the complex was in a very bad condition; it had lost a lot of decoration elements, cracking, soot deposition, insects’ holes, and fungi growth. This research will discuss the various deterioration phenomena that have effect on the main building materials and cause the damages and discuss the general scientific methodology of the architectural and structural conservation project which was carried out.


Historical and Architectural Background
The mosque-Kutab & Sabil of Hasan Pasha Tahir belonged to Ottoman period. It was built in 1809 ad-1224 h by Hasan pasha Tahir and his brother Abdin Bey Tahir in Sayyida Zaynab. The complexes take No. 210, located in the banks of Birkat al-Fil (elephant pond 1 ), Port Said Street, Cairo.

Architecture elements of Sabil and Kuttab
The main façade it is characterized by the main entrance, which contains two mastapa and a three-pronged orthodontic arc. The entrance is topped by a marble lintel carved with the foundation text of the mosque. The facade was deformed by the earthquake. It is characterized by excessive ornamentation. It

Construction Systems
Bearing walls construction: The facade was constructed with limestone bearing   bearing the decorative elements and there on the square (right-angled) from both sides of it an installed wooden decoration which is known to the workmen as the sole and extends by a tongue between the stalactites that helps in protecting the bottom of both sides of the Baratim from the effects of air on the decorations or it may be an installed one on the Baratim angles for a decorative purpose, on both sides of it there are wooden ornaments called "the swimmer", proving the hull sides of it In addition to the decorative form, it works to fill any holes between the Baratim and wooden pallets and crocodiles ( Figure 4). Complementary elements of wooden ceilings 1) Hernaúa: Known to the workmen by that name, which is a rectangular piece of wood placed between each two Brtom when, and fixed with nails, it hides behind the walls and the rest of it which is uncoated, and maintains the distance confined between the wood beams and the others.
2) Alqtronah: Which is fixed to the bottom of wooden planks with nails, and to be perpendicular to the wall to hide the Baratim overlap in the wall, and be a liaison between the wood beams, the Izar and Hernaúaat. led to that each structural element takes an independent behavior according to its properties ( Figure 5) [1]. Seismic performance is affected to any premises with two main factors soil properties that it is building, and earthquake waves depending on soil type and shape layers and their characteristics in terms of solidity and coherence, as well as seismic performance is affected by the properties World Journal of Engineering and Technology  of the building itself, whether the underground or the tip above in terms of guiding a projected interfaces and type of construction in the building [2]. Tendencies and incline the marble column and fall off area of gravity and move the wooden pillow top of the crown. Many vertical, diagonal cracks in the walls as shown in which led to dangerous deterioration in the architectural elements like arches, gifts and threshold more cracks were found at top of the façade. The cracks at top of facade and at the end of facade are indicating to continuous wave movements. Vertical cracks generally indicate poorly bonded material that has, vertical cracks generally indicate to poorly bonded material that has lost its cohesion and is therefore weak. Black crust and soiling were coated the surfaces of Sebil and Kutab building materials resulting from atmospheric pollution from the center of Cairo ( Figure 6). The main of stone deterioration of the façade results from combination of raised groundwater level and the capillary transport of salt laden water due to the actual level of humidity and its continuous mechanism. The pressure of salt crystallization enhances the growth and development of micro and macro fractures and consequently leads to granular disintegration, scales, spalling, flaking prevail inside and breaks up stone surface and also decrease the overall strength of the stone especially in the lower parts of the walls [3].   -The wood ceiling and its decorative paintings on the Sabil and Kuttab were in a very bad condition, which created by a combination of organic and inorganic materials. It had several different deterioration marks, as; warps, twists and irregular shape dry wood used in the ceilings, to shift mostly to curly plates wrapped wooden beams as a result of changes in temperatures and humidity daily, seasonally and annually, which lead to the separation of wood panels that carry layers of color, which lost large parts of them.

The Wood Ceiling of the Sabil & Kuttab
-Spread of cracks and deep cracks between wooden panels: that comprises the ceilings as well as the proliferation of these cracks in colorful layers above those panels.
-Colored material used in decoration had an occurred chromatic as color shift phenomenon of change as a result of chemical degradation resulting from the impact of heat and humidity and air pollution and the material became darker and lost its originality and beauty.
-The ceiling had been damaged and loss of many architectural elements as a result of biological attack.
-In addition to insects attack ceilings and caused tearing wood fiber with microorganisms and turned large parts of that to weak soft wood.
-All of this type of physical damage has had a direct impact in the collapse of these ceilings, especially with the continuous movement and collapse of the walls carrying them. All deterioration aspects shown in (Figure 8, Figure 9).

Materials and Methods
Since samples had to be collected for analysis, they were taken from selected World Journal of Engineering and Technology

SEM Examination
The obtained results showed that there is a wide range of deterioration of limestone ( Figure 11

SEM-EDX Examination
EDX analysis of altered limestone (Figure 13

Mineralogical Analysis by XRD
XRD patterns of the limestone samples are given in (Figure 14), show that the sample consists essentially of calcite CaCO 3 , Quartz SiO 2 , Albite NaAlSi 3 O 8 and traces of iron oxide.

Physical and Mechanical Tests of Limestone Results
The physical properties detected that the limestone of the facade is characterized by medium porosity (5.46%), water absorption rate (2.38%) and its consequent ability to absorb water with salt solution and this is the main cause of deterioration. The bulk density of the samples gives (2.29 gm/cm 3 ) ( Table 1)      kg/cm 2 ) Dry and 175 kg/cm 2 Wet (Table 1). The changes of physical and mechanical properties of the stone were a result of weathering.

Grouting Type & Soil Type
From the Results of test, we can classify to clay soil in top and sandy soil below it World Journal of Engineering and Technology ( Figure 15), from this identification we can use grouting with this spil without pressure all most

Characterization of the Wooden Ceiling and Its Decoration
The decorative motifs of wooden ceiling wear applied as follows: the wood panels were covered with ground layer and painted with paint layer with pigments.

Ground Layer Results
The elemental composition analysis carried by EDS of ground layer ( Figure   16

Paint Layer
Chemical of the pigments have been determined by SEM-EDS analysis, the

Fournier Transforms Infrared Spectroscopy (FTIR) Analysis
The aim of this study is to identify organic binders in used as an intermediary.
Sample from the red pigment was analyzed to identify the binders used with these pigments. The results were compared with standard samples of both animal glue and Arabic gum. Results showed that the tested samples have a high proportion of animal glue (Figure 17).

Mechanical Properties of Wood Results
This part is aimed to outline and discuss the measured mechanical properties of the wood samples the wood celling. Compressive strength (Figure 18(a)), tensile strength ( Figure 18(b)) and shear strength (Figure 18(c)) are presented in Table 2.

■ Decomposition of wooden ceilings
-The different elements of the ceilings were deconstructed as one unit with carful and assembled according to the technical specifications, after recording their sectors and the structural system for them on drawings with a suitable scale to restore the object to its original after restoration and reinforcement.
-Make a layer of foam panels on top of the decorated ceiling. World Journal of Engineering and Technology   -Installation of wooden beams (8 × 6) inch down and top of the ceiling perpendicular to the direction of the ceiling sections and are connected by Stainless nails. ■ Reconstruction of wood ceiling -The flat ceilings consist of a group of wood beams based on the walls according to the distance between the walls and then come a vertical layer of wood panels (Figure 19).
-In the reconstruction, wooden beams added on the walls so that they can distribute loads along the wall (Figure 20).
-Construction filling layers and the necessary tendencies for water drainage.
■ Cleaning -Mechanical cleaning: This method is implemented by using multiple types of Brushes with soft hairs to remove dust and use medical and metal scalpels edges to remove salts and dust layered roofs colored glue. It was also using electrical appliances that push or pull to dust and damage output. And these stages must be done very carefully so as not to cause damage to photographic layers.    -Microscopic analysis results showed that most of the wood panels and the overlying colored layers in a severe case of weakness and incoherence. To strengthen these panels and those layers chemically using modern chemical polymers that are suitable for such cases has been tested many polymers such as polymerized vinyl acetate, caltone and area gal all which were Acrylic polymers, but they did not give good results ( Figure 22). -Experience has shown that this Polymer resists the effects of heat and humidity and does not change color over time has proven that microorganisms can devour thin protective made this colorful substrates and wood panels prior to that was a former exterminator for limiting the gravity of these objects to this solution during treatment.

Reconstruction of Facade of Sabil & Kuttab
The dismantling and reconstruction operations were an exceptional solution to the extreme necessity, especially with the structural and architectural deterioration due to the various soil problems on which the building was built. Therefore, all measures and precautions were taken to ensure that the components that were decomposed according to their Original location. The Reconstruction process was carried out as follows.

■ Disassembly & reassembly
-Conduct an integrated and scientific study to determine the current status of the interface elements.
-The numbering system for each piece is determined exactly the exact position and sign this numbering on drawings, and the classification tables for the numbered pieces were made (Figure 23).
-The monitoring work was carried out by a surveying system to determine the directions and to monitor the elevations necessary to ensure that the pieces were reconstructed in their original positions and directions.
-Determine the relationships between the numbered pieces and recording on drawing works to ensure the reconstruction process [4]. World Journal of Engineering and Technology  Considering the central pressure forces are the main loads applied to these columns so as to ensure that stress stresses are among the permissible values World Journal of Engineering and Technology for carrying buildings, also the wooden pillow was replaced which are usually a middle stage between the leg of arch and crown of column for the importance of its structural role in the reduction of loads and absorption of vibrations ( Figure 25). ■ The arch is the ceiling-mounted element that is distributed to the load from the ceiling on columns and side bearing walls to reach the bearing soil. Depending on the shape of the arch in resistance to pressure stresses generated by the horizontal ceiling loads applied to the arch, supporting the end of arches to provide stability and horizontal push resistance. Because the crown was separated from the shaft cylinder, an iron-beam was attached between the end of the upper column and the crown, to making the largest points to resist horizontal forces. ■ A final finishes and repointing using soft mortar according to original chemical composition and enhanced in its properties as shown in Table 3.

Conclusion
The architectural complex of Hassan Pasha Taher is characterized by overlapping between the architectural and human functions and must be restored to play its role in the development of the surrounding society, so this paper refers to considering the function of the building after restoration, structural interference in building elements and the difficulty of structural separation between elements. The paper concerned the necessity of improving the materials used in

Conflicts of Interest
The author declares no conflicts of interest regarding the publication of this paper.