Chemical composition of building materials used in Turkey

The main goal of this work was to determine the chemical composition of building materials used in Turkey by utilizing energy dispersive X-ray fluorescence (EDXRF) spectrometry. Gas concrete, cement, sand, bricks, roofing tiles, marble, lime and gypsum materials were selected as building materials for this research. The chemical contents and their trace concentrations of the selected samples were determined. The most abundant oxides measured were generally SiO₂, Al₂O₃, CaO, MgO, Fe₂O₃, K₂O and SO₃ for all samples. While the main chemical component of gas concrete, cement, sand and marble samples were SiO₂ and CaO, brick and roofing tile mainly consisted of SiO₂ and Al₂O₃. CaO and SO₃ were major component of lime and gypsum samples, respectively. For U and Th concentrations in the samples, activities of ²²⁶Ra and ²³²Th were measured by utilizing gamma spectrometry. ANOVA and Pearson correlation analyses were performed on the studied data for statistical analysis.     

Bearing failure in stainless steel bolted connections

Although the mechanical behaviour of stainless steel and carbon steel differs significantly, design provisions for stainless steel connections in current standards are essentially based on the rules for carbon steel. For bolted connections, the design resistances in EN 1993-1-4 and the SCI/Euro Inox Design Manual for Structural Stainless Steel are based on those in EN 1993-1-8 and EN 1993-1-3 with only some minor modifications. In this paper, an investigation into the bearing behaviour of stainless steel connections between both thick and thin plates has been conducted. Numerical models for previously tested specimens in austenitic and ferritic stainless steel have been developed and validated. The validated models were then used to perform parametric studies to investigate the key variables affecting the bearing failure of bolted connections; these include edge distance e₂, end distance e₁ and plate thickness t. The investigation showed the deformation behaviour of stainless steel connections to be somewhat different from that of carbon steel connections, with stainless steel exhibiting pronounced strain hardening. However, the locations of fracture initiation obtained from the numerical models matched those observed during experimental studies of both carbon steel and stainless steel connections and this feature has been used as the basis for defining a consistent, strength based criterion of failure. The results of the parametric studies have been utilised as the basis for design provisions for bearing failure in stainless steel bolted connections that cover both the ultimate and the serviceability limit states and which are both more economic and more straightforward than the present EC3 provisions.     

CuFe2O4 as heterogeneous catalyst in degradation of p-nitrophenol with photoelectron-Fenton-like process

In this research, the heterogeneous photoelectron-Fenton-like process using copper ferrite (CuFe₂O₄) as catalyst was employed to remove p-nitrophenol (PNP). The CuFe₂O₄ catalyst was prepared by a co-precipitation process and characterised with X-ray fluorescence analysis, X-ray diffraction analysis and BET surface area. The results confirmed that CuFe₂O₄ was prepared successfully. Under the optimum conditions, namely 0.05?mol?L^?1 Na₂SO₄, the electrical potential of ?0.6?V, pH 3.0 and 0.067?g?L^?1 CuFe₂O₄, 92.8% of 0.1?mM?L^?1, the PNP removal efficiency could reach 92.8% for 0.1?mM?L^?1 PNP after 180-min treatment. This technology can be applied for the treatment of organic compounds which are not readily biodegradable.     

Microstructure,physical and mechanical properties of mortar–rubber aggregates mixtures

This work focuses on the feasibility of reusing and valorising rubber aggregates from shredded worn tyres in cement composites. Our purpose is to study the influence of both microstructures of matrix and of interfacial transition zone (ITZ) on mechanical properties of mortar–rubber aggregates mixtures. The same volume of rubber aggregates substituted volume fractions of sand. Volume ratios of rubber aggregates were ranged from 0% to 50%. Micro structural morphology of various samples was observed by means of scanning electron microscopy (SEM). The matrix porosity and the evolution of hydration products (CSH, CaOH₂, CaCO₃) were estimated for specimens that had been curing for 28 days at constant temperature and constant relative humidity. An energy dispersive X-ray analyser and X-ray diffraction were used together with SEM in order to quantify these results.     

Studies on termite hill and lime as partial replacement for cement in plastering

This study investigated the compressive strength and water absorption capacity of 50×50×50 mm mortar cubes made from mixes containing lime, termite hill and cement and sand. Two mix ratios (1:4 and 1:6) and varying binder replacements of cement with lime or termite hill amounting to 0%, 10%, 20%, 30%, 40% and 50% were used. Test results showed that the compressive strength of the mortar cubes increases with age and decreases with increasing percentage replacement of cement with lime and termite hill. However, for mix ratio 1:6, up to 20% replacement of cement with either lime or termite hill, all the mortar cubes had the same strength; subsequently, the termite hill exhibited a higher compressive strength. For mix ratio 1:4, mortar cubes made from lime/cement and termite hill/cement mixtures had the same strength at 50% replacement. Generally, water absorption is higher in mixtures containing lime (18.10% and 14.20% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level) than those containing termite hill (16.10% and 13.02% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level). Termite hills seem to be promising as a suitable, locally available housing material for plastering.     

Optimization of hydroxyl radical production using electro‐Fenton method for chemical oxygen demand reduction in diluted palm oil mill effluent

Palm oil mill effluent (POME) is a well‐known highly polluting wastewater due to its extremely high contents of organic matter, suspended solids and nutrients. In this study, we used electro‐Fenton method to treat POME by optimizing OH? generation from hydrogen peroxide (H₂O₂) under low voltage input (1.5–6.0 V). A set of electro‐Fenton system was set up using stainless steel as the anode and graphite as the cathode. Four parameters namely retention times, concentrations of H₂O₂ as well as FeSO₄ catalyst and applied voltages were studied. The results were reflected in the form of removal efficiency of chemical oxygen demand (COD). The optimum conditions to degrade organic matter in POME were found to be in 4 h retention time with the respective H₂O₂ and FeSO₄ catalyst concentrations of 0.05 and 0.10 M, and the power input of 1.5 V. Under such conditions, the maximum COD removal efficiency achieved 94%. The electro‐Fenton treatment was found to have higher efficiency than the conventional Fenton treatment. Without the electrolysis, the COD removal efficiency of the conventional Fenton treatment was only 48%.     

Development of a cementless mortar using hwangtoh binder

This paper presents the properties of a cementless mortar developed to produce eco-friendly building material without carbon dioxide emissions and with various beneficial effects. The binder, hwangtoh binder (HB), used in this mortar was developed by reaction of a very small amount of inorganic minerals and activated hwangtoh, which is rich in silica, SiO₂, and alumina, Al₂O₃. To investigate the compressive strength and shrinkage deformation of the cementless mortar using HB, HB mortar, water–HB ratio, fine aggregate–HB ratio, and the maximum size and grading of fine aggregate were selected as the main variables of test specimens classified into three groups. The test results presenting the effect of various parameters on the properties of HB mortar confirmed that the developed HB has a highly effective performance as a binder. The equations using nonlinear multiple regression analysis based on the test results are represented to assess the flow and 28-day compressive strength of HB mortar. Comparisons between predicted and measured flow and 28-day compressive strength show good agreement.     

Analysis of the mechanism of sludge ozonation by a combination of biological and chemical approaches

Using the practical sludge obtained from municipal sewage treatment plants, the mechanism of the sludge ozonation process was systematically investigated by a combination of biological and chemical approaches, including analysis of the changes in biological response by CFU and PCR-DGGE, bio-macromolecular activity and radical scavenging activity. The results indicated that after the sludge was exposed to ozone at less than 0.02 g O₃/g TSS, the DGGE fingerprint remained constant and there was still some enzyme activity, indicating that the sludge solubilization was the main process. At greater than 0.02 g O₃/g TSS, the bacteria began to be broken down and ozone was used to oxidize the bio-macromolecules such as proteins and DNA released from the sludge. Bacteria belonging to ‘G-Bacteria’ were able to conserve their DNA in the presence of less than 0.08 g O₃/g TSS. At levels higher than 0.10 g O₃/g TSS, the disintegration of the sludge matrix became slow and the microbes lost most of their activity, and ozone was used to transform the bio-macromolecules into small molecules. However, at levels higher than 0.14 g O₃/g TSS, the ozone failed to oxidize the sludge efficiently, because several radical scavengers such as lactic acid and SO₄²⁻ were released from the microbial cells in the sludge.     

Phase transformation and its role in stabilizing simulated lead-laden sludge in aluminum-rich ceramics

This study investigated the mechanisms of stabilizing lead-laden sludge by blending it into the production process of aluminum-rich ceramics, and quantitatively evaluated the prolonged leachability of the product phases. Sintering experiments were performed using powder mixtures of lead oxide and γ-alumina with different Pb/Al molar ratios within the temperature range of 600–1000 °C. By mixing lead oxide with γ-alumina at a Pb/Al molar ratio of 0.5, the formation of PbAl₂O₄ is initiated at 700 °C, but an effective formation was observed when the temperature was above 750 °C for a 3-h sintering time. The formation and decomposition of the intermediate phase, Pb₉Al₈O₂₁, was detected in this system within the temperature range of 800–900 °C. When the lead oxide and γ-alumina mixture was sintered with a Pb/Al molar ratio of 1:12, the PbAl₁₂O₁₉ phase was found at 950 °C and effectively formed at 1000 °C. In this system, an intermediate phase Pb₃(CO₃)₂(OH)₂ was observed at the temperature range of 700–950 °C. Over longer leaching periods, both PbAl₂O₄ and PbAl₁₂O₁₉ were superior to lead oxide in immobilizing lead. Comparing the leaching results of PbAl₂O₄ and PbAl₁₂O₁₉ demonstrated the higher intrinsic resistance of PbAl₁₂O₁₉ against acid attack. To reduce metal mobility, this study demonstrated a preferred mechanism of stabilizing lead in the aluminate structures by adding metal-bearing waste sludge to the ceramic processing of aluminum-rich products.     

Effects of stabilizers on CO2 fixation capacity in neutralization of alkali construction sludge

Construction sludge, generated from tunneling and piling, is typically in a liquid state. It can be improved via physical treatments, such as dehydration, and/or chemical treatments, using stabilizers, in order to to be recycled as construction material. To adjust the strength of sludge, chemical treatments are often preferred. However, chemical treatments frequently result in alkali leaching. Methods to reduce alkalinity by curing the alkaline sludge under CO₂ gas at a certain concentration have been proposed in Japan. In recent years, technologies that utilize CO₂ to improve the quality of cementitious material have received considerable attention in terms of carbon capture. Therefore, the effects of stabilizers on the CO₂ fixation capacity of alkaline sludge during pH neutralization were investigated in this study. Accelerated carbonation and carbonate content measurement tests were conducted to detect the CO₂ content fixed in alkaline sludge specimens treated with various stabilizers. The test results showed that the fixed maximum CO₂ content per gram of dry mass of sludge, (m_CO2)^max, increased with the calcium oxide (CaO) content of the stabilizer(s) per gram of dry sludge, C_CaO. However, the rate of increase in (m_CO2)^max with C_CaO was significantly affected by the type of stabilizer used. In the case of quicklime (QL), the ratio of (m_CO2)^max to C_CaO was approximately 0.5, whereas, in the cases of fly ash (FA) and steel slag (SS), the ratio was approximately 0.25. The ratios for biomass ash and paper sludge ash were between that for QL and that for FA and SS. Detailed analyses of the test results suggest that the CaO content per gram of stabilizer(s) in the sludge, C*_CaO, can provide an estimate of the fixed maximum amount of CO₂ per gram of stabilizer(s) in the sludge, (m*_CO2)^max. However, other factors, including the amount of water-soluble Ca, should be considered for a precise evaluation. Additionally, the experimental results showed that the decrease in pH owing to neutralization increases with the increasing C_CaO. However, the type of stabilizer did not significantly affect the relationship between the degree of CO₂ fixation and the degree of neutralization.     

Treatment of a sanitary landfill leachate using combined solar photo-Fenton and biological immobilized biomass reactor at a pilot scale

A solar photo-Fenton process combined with a biological nitrification and denitrification system is proposed for the decontamination of a landfill leachate in a pilot plant using photocatalytic (4.16 m² of Compound Parabolic Collectors - CPCs) and biological systems (immobilized biomass reactor). The optimum iron concentration for the photo-Fenton reaction of the leachate is 60 mg Fe²⁺ L⁻¹. The organic carbon degradation follows a first-order reaction kinetics (k = 0.020 L kJ_UV⁻¹, r₀ = 12.5 mg kJ_UV⁻¹) with a H₂O₂ consumption rate of 3.0 mmol H₂O₂ kJ_UV⁻¹. Complete removal of ammonium, nitrates and nitrites of the photo-pre-treated leachate was achieved by biological denitrification and nitrification, after previous neutralization/sedimentation of iron sludge (40 mL of iron sludge per liter of photo-treated leachate after 3 h of sedimentation). The optimum C/N ratio obtained for the denitrification reaction was 2.8 mg CH₃OH per mg N-NO₃⁻, consuming 7.9 g/8.2 mL of commercial methanol per liter of leachate. The maximum nitrification rate obtained was 68 mg N-NH₄⁺ per day, consuming 33 mmol (1.3 g) of NaOH per liter during nitrification and 27.5 mmol of H₂SO₄ per liter during denitrification. The optimal phototreatment energy estimated to reach a biodegradable effluent, considering Zahn-Wellens, respirometry and biological oxidation tests, at pilot plant scale, is 29.2 kJ_UV L⁻¹ (3.3 h of photo-Fenton at a constant solar UV power of 30 W m⁻²), consuming 90 mM of H₂O₂ when used in excess, which means almost 57% mineralization of the leachate, 57% reduction of polyphenols concentration and 86% reduction of aromatic content.     

Characterization of the heterotrophic biomass and the endogenous residue of activated sludge

The activated sludge process generates an endogenous residue (X_E) as a result of heterotrophic biomass decay (X_H). A literature review yielded limited information on the differences between X_E and X_H in terms of chemical composition and content of extracellular polymeric substances (EPS). The objective of this project was to characterize the chemical composition (x, y, z, a, b and c in C_xH_yO_zN_aP_bS_c) of the endogenous and the active fractions and EPS of activated sludge from well designed experiments. To isolate X_H and X_E in this study, activated sludge was generated in a 200 L pilot-scale aerobic membrane bioreactor (MBR) fed with a soluble and completely biodegradable synthetic influent of sodium acetate as the sole carbon source. This influent, which contained no influent unbiodegradable organic or inorganic particulate matter, allowed the generation of a sludge composed essentially of two fractions: heterotrophic biomass X_H and an endogenous residue X_E, the nitrifying biomass being negligible. The endogenous decay rate and the active biomass fraction of the MBR sludge were determined in 21-day aerobic digestion batch tests by monitoring the VSS and OUR responses. Fractions of X_H and X_E were respectively 68% and 32% in run 1 (MBR at 5.2 day SRT) and 59% and 41% in run 2 (MBR at 10.4 day SRT). The endogenous residue was isolated by subjecting the MBR sludge to prolonged aerobic batch digestion for 3 weeks, and was characterized in terms of (a) elemental analysis for carbon, nitrogen, phosphorus and sulphur; and (b) content of EPS. The MBR sludge was characterized using the same procedures (a and b). Knowing the proportions of X_H and X_E in this sludge, it was possible to characterize X_H by back calculation. Results from this investigation showed that the endogenous residue had a chemical composition different from that of the active biomass with a lower content of inorganic matter (1:4.2), of nitrogen (1:2.9), of phosphorus (1:5.3) and of sulphur (1:3.2) but a similar content of carbon (1:0.98). Based on these elemental analyses, chemical composition formulae for X_H and X_E were determined as CH_1.240O_0.375N_0.200P_0.0172S_0.0070 and CH_1.248O_0.492N_0.068P_0.0032S_0.0016, respectively. Data from EPS analyses also confirmed this difference in structure between X_E and X_H with an EPS content of 11-17% in X_Eversus 26-40% in X_H.     

珊瑚砂浆的力学性能与微观结构特征

研究了珊瑚砂-水泥砂浆(珊瑚砂浆)的力学性能,以及复合矿物掺和料对珊瑚砂浆的改性作用,并与标准砂浆进行对比.采用扫描电子显微镜-能量弥散X射线谱(SEM-EDS)、X射线衍射(XRD)和傅里叶变换红外光谱(FTIR),对砂浆力学性能、体积稳定性和水化作用的微观机理进行了研究.结果表明:珊瑚砂浆的力学强度低于标准砂浆,加入复合矿物掺和料后可改善水泥石基体及界面过渡区的微观结构,提高珊瑚砂浆的力学性能,使其28d抗压强度较标准砂浆提高了2.1%;珊瑚砂凹凸不平的表面能与硬化水泥浆体形成紧密的啮合状态,有助于提高砂浆的体积稳定性;珊瑚砂的内养护作用使砂浆的力学性能和抵抗收缩能力得到了提高;粉煤灰和矿粉的微集料填充作用和火山灰效应,提高了珊瑚砂浆的力学性能和抗氯离子扩散能力;珊瑚砂持续释放出的Ca^2+、Mg^2+参与了水泥的水化反应,有助于生成更多的水化产物.     

Recovery of boric and phosphoric acid residues from wastewater

Residues obtained from boric and phosphoric acid factories cause some undesired environmental problems. B2O3 in sludge and reactor waste causes serious environmental problem. Recovery of B₂O₃ and P₂O₅ are important processes in the prevention of water pollution and the utilization of waste mud. Both residues include mainly borogypsum, phosphogypsum and impurities. In order to recover B₂O₃, Li, P2O5, F and other water‐soluble constituents, the residues were extracted at different temperatures with water, and by lime milk. P₂O₅ and F remove completely from wastes by washing with milk of lime. 47% of B₂O₃ is removed by extracting with hot water.     

Effectiveness of different oxidizing agents for removing sodium dodecylbenzenesulphonate in aqueous systems

The present study investigates the efficacy of various oxidizing treatments (ClO⁻, ClO₂, KMnO₄, O₃, O₃/H₂O₂, O₃/activated carbon) to remove from waters sodium dodecylbenzenesulphonate (SDBS), considered as model surfactant. Results obtained show that the use of ClO⁻ and ClO₂ does not cause appreciable SDBS degradation. Additionally, in the case of ClO⁻, trihalomethanes are generated, increasing system toxicity. Because the reaction kinetics between SDBS and KMnO₄ is very slow, a decrease in contaminant concentration is not observed, even at very acid pH values. SDBS reactivity with ozone is very low, with a kinetic constant (kO3) of 3.68 M⁻¹ s⁻¹, but its reactivity with HO radicals is very high (k_OH = 1.16 × 10¹⁰ M⁻¹ s⁻¹), therefore O₃/H₂O₂ and O₃/activated carbon, which can also generate HO, appear as promising advanced oxidation processes to remove this contaminant from waters. The method based on ozone and activated carbon was the only process studied that produced both an increase in SDBS removal rate (due to the generation of HO radicals in the O₃-PAC or O₃-GAC interaction) and a considerable reduction in the concentration of dissolved organic carbon in the system due to the PAC adsorbent properties.     

Stabilization of heavy metals in sludge ceramsite

This paper attempts to investigate the stabilization behaviours of heavy metals in ceramsite made from wastewater treatment sludge (WWTS) and drinking-water treatment sludge (DWTS). Leaching tests were conducted to find out the effects of sintering temperature, (Fe₂O₃ + CaO + MgO)/(SiO₂ + Al₂O₃) (defined as F/SA ratios), pH, and oxidative condition. Results show that sintering exhibits good binding capacity for Cd, Cr, Cu, and Pb in ceramsite and leaching contents of heavy metals will not change above 1000 °C. The main crystalline phases in ceramsite sintered at 1000 °C are kyanite, quartz, Na-Ca feldspars, sillimanite, and enstatite. The main compounds of heavy metals are crocoite, chrome oxide, cadmium silicate, and copper oxide. Leaching contents of Cd, Cu, and Pb increase as the F/SA ratios increase. Heavy metals in ceramsite with variation of F/SA ratios are also in same steady forms, which prove that stronger chemical bonds are formed between these heavy metals and the components. Leaching contents of heavy metals decrease as pH increases and increase as H₂O₂ concentration increases. The results indicate that when subjected to rigorous leaching conditions, the crystalline structures still exhibit good chemical binding capacity for heavy metals. In conclusion, it is environmentally safe to use ceramsite in civil and construction fields.     

The adsorption of bovine serum albumin by activated sludge

The rapid removal, from suspension, of between 2–% of bovine serum albumin (BSA) by BSA acclimated activated sludge was attributed to adsorption. The extent of adsorption varied with the substrate to biomass (s/b) ratio. The concentration of BSA adsorped was influenced by both the concentration of BSA and the concentration of activated sludge. The experimental data did not conform to the calssical adsorption equations of Langmuir (J. Am. chem. Soc.40, 1361–1403, 918) or Freundlich (Colloid and Capillary Chemistry, Methuen, London, 1926) but to a newly developed equation, the activated sludge adsorption equation (ASAE). This new equation was tested and proven by experimental data and by data obtained independently by Banerji et al. (J. Wat. Pollut. Control Fed.40, 161–173, 1968) who investigated starch removal by activated sludge. Following the development of the ASAE, it was found possible to express both the concentration of BSA adsorbed per unit weight activated sludge (m) and the concentration of BSA in equilibrium per unit weight activated sludge (C/b) as a function of the concentration of BSA added to the system per unit weight adsorbent (C_t). Thus adsorption could be expressed as a function of the substrate to biomass (s/b) ratio.     

Photocatalytic Destruction of Fulvic Acids by Various Oxidants in a Reactor with Immobilized TiO<Subscript>2</Subscript>

Comparison of the efficiency of photocatalytic oxidation of aqueous solution of fulvic acids (TOC₀—15.9–17.1 mg/dm³, pH0 6 ± 0.1) by oxygen of the air, hydrogen peroxide and ozone in a reactor containing a wide-porous ceramic block with immobilized TiO₂ with the variation of the concentration of H₂O₂, feed rate of O₃ and temperature showed advantages of photocatalytic ozonization and expediency of its use for deep destruction of natural organic substances in water. The maximum degree of destruction in photocatalytic systems O₂/TiO₂/UV, H₂O₂/TiO₂/UV and O₃/TiO₂/UV constituted respectively 41, 73 and 90% for TOC for 5, 4 and 3 h.     

Soil properties, foundation stability, groundwater conditions, characteristics of building stones and mortar used in construction and proposed measures for restoration at the site of ancient Ayla in a Qaba, Jordan

Ancient Ayla in Aqaba, Jordan was destroyed during a major earthquake incident that occurred in Aqaba in 1067 AD. The Gulf of Aqaba is a seismically active region. The latest strong earthquake incident occurred on November 22, 1995 when an earthquake of local magnitude 6.2 rocked the Gulf of Aqaba region. The main shock was followed by thousands of aftershocks. The Gulf of Aqaba-convering the geologic coordinates 28.0–29.6 N; 34.5–35..2 E is one of two natural bays surrounding the Sinai Peninsula which itself is located at the northernmost end of the Red Sea. The soil profile underlying Aqaba city consists of interlayering of various sedimentory Holocene Alluvium deposits. This study is aimed at investigating the soil and foundation condition at the site of the ancient Ayla. This includes groundwater conditions, bearing capacity of the strata supporting the walls of ancient Ayla, and structural stability of these walls. The study included an investigation of the characteristics of building stones used in the earlier construction as well as those proposed for use in the restoration of Ancient Ayla. Furthermore, the physical and chemical properties of existing mortars were evaluated. Gradation analyses were conducted to select a proper sand for use in the mortar mix. Mortar mix tests were conducted for the purpose of recommending a mortar mix for use in restoration works. Trends in the results of various mix tests were analyzed. Sample borings were made at the site to obtain soi profile and extract soil and water samples. Standard Penetration test was conducted at different depths. Laboratory tests were performed on these samples to determine pertinent physical properties of the soil and salinity of the water. Soils at the site were found to be predominantly granular with archaeological fill overlying beach sand which in turn overlies the coarser sand and gravel of the natural deposits. Except for the wadi area, groundwater was encountered at about 3 m below existing ground levels. Bearing capacity of the foundation was evaluated to be 3.5 kg/cm² for the dense granular materials (that represent the probable founding layer of the existing walls), and 2.0 kg/cm² for the weaker silty/clayed zone. Back analysis yields a safe wall height of at least 6.0 m. Therefore, no stability problems are present. Tilting and sinking were noted in some portions of the exterior walls as a result of dynamic lateral earth pressures exerted during the major earthquake incident of 1067 AD. Measures for wall foundation support during archaelogical excavations are suggested. Permanent excavations for exposing the walls should be limited to a free height of about 3 m at the location of western wall, and about 2.5 m at the location of the eastern wall. Stones used in the construction of ancient Ayla were found to consist of precut sandstone, siltstone, mudstone and granite. Weathering effects were clearly noted on the exposed stones in the walls. It is proposed to use a replacement stone consisting of sandstone group located at a source 35 km North of Aqaba. Measures suggested for the restoration of the walls addressed the lack of mortar in the inner walls and the replacement of disintegrated stone pieces in the external walls. Existing mortars were found to consist primarily of three types, namely a brown silty mixture, a gray mixture, but predominantly a mixture of fine gravel and a lime/gypsum binder. The major chemical constituents of the original mortar are 18 % SiO₂, 23 % CaO, and 34 % SO₃. X-ray diffraction peaks indicate the presence of gypsum, calcite and quartz. Comparative analysis data gave 7 % CaCO₃, 53 % Sand, and 40 % Solubles as average values of the constituents. Following the selection of two sand sources for use in the mortar mix, recommended mortar for restoration was a mix of lime, sand, ash, with ratios of 1:3:1.5.