Rehabilitation of Al-Shawbak Castle Using El-Lajjun Bituminous Limestone Ash Mortars and Plasters.

Al-Shawbak castle mortars and plasters were characterized through physical, mechanical and chemical analysis. The studied masonry and plaster mortars have shown intensive weathering and erosion features, low compressive strength, and high absorption and disintegration behavior when soaked in water. Limy ash has been prepared from the El-Lajjun bituminous limestone by direct combustion at 950°C in an attempt to rehabilitate Al-Shawbak castle. The ash has been mixed with sand and water to prepare self cementitious mortar material that gain strength at normal ambient temperature. The laboratory tests have been selected with respect to construction needs in various remedial works in archeological sites to replace weathered and eroded masonry and plaster mortars. The limy ash mortar has similar color, chemical and mineralogical composition similar to the tested ancient mortar and plaster samples. The mortar has a higher compressive strength and resistively to disintegration under saturation conditions. The ash mortars could be used to rehabilitate various damaged archeological parts of AL-Shawbak Castle.