Papers by Ahmed Abd El-aal
Geotechnical and Geological Engineering, 2020
As quality soils become scarce and their location is more difficult and expensive, it becomes inc... more As quality soils become scarce and their location is more difficult and expensive, it becomes increasingly necessary to improve soil quality through soil stabilization. The benefits of energy saving and resource conservation, effective recycling of all solid wastes (fly ash, slag, lime, marble dust, etc.) has become a global concern that requires research and development. This article presents the results of a laboratory tests to investigate the effects of marble powder and lime on compaction characteristics, Atterberg limits, shear strength parameters, and unconfined compression test of two Algerian soils. Marble powder and lime are added in varying percentages (2%, 4%, and 6% by weight) to the soil samples. Test results reveal that the liquid limit and plasticity index decrease, whereas the plastic limit increases with the addition of lime and marble powder for soil A and soil B, in which the decrease is more significant with soil A than soil B. The unconfined compressive strength increased with increasing curing time and percentages of lime and marble powder for the two soils. The highest unconfined compressive strength was achieved at 6% marble powder for soil B after 28 days. The addition of marble powder for both soils decreased the optimum moisture content and increased the corresponding maximum dry unit weight. However with lime addition, both soils show decrease in the optimum moisture content and in the corresponding maximum dry unit weight. The shear strength parameters increased for both soils with increase of lime percentages. Whereas for the addition of marble powder, there is an increase of friction angle and decrease of cohesion for soil A. There is considerable change for soil B with marble powder, a decrease in friction angle and an increase in cohesion. The results show that marble powder could be used as a stabilizer for soils with high clay content and known mineralogy composition. In addition, it is very important to get rid of its negative effect on environment and to obtain economical benefit from it.
Arabian Journal for Science and Engineering, 2021
The partial substitution of ordinary Portland Cement (OPC) with clay minerals as supplementary ce... more The partial substitution of ordinary Portland Cement (OPC) with clay minerals as supplementary cementitious materials has been currently considered as an effective approach for reducing the harmful environmental impact and health risks of OPC. Although cement mortars are not easily ignitable, the exposure to elevated temperatures can alter their microstructure, leading to reduction in the strength and damage. Therefore, improving the temperature resistance of the cement mortars through the incorporation of local clay minerals has been proposed in this study. The mechanical performance and physical properties of cement mortars containing Wasia Formation clay (WFC) exposed to 700 °C have been investigated. OPC was partially replaced with WFC at various mass ratios of 0, 5, 10, 15, and 20 wt%. Several methods were used to assess the physico-mechanical and structural properties such as compressive strength testing, ultrasonic pulse velocity (UPV), Schmidt hamme, scanning electron microscopy, and X-ray powder diffraction (XRD). The addition of WFC as partial replacement of the cement showed a significant enhancement in the compressive strength for the mortars exposed to normal and elevated temperatures. The compressive strength of the mortar incorporating 20 wt% of WFC and exposed to 700 °C is about 2.5-fold greater than that of the ordinary mortar. Even after exposure to 700 °C, the UPV for the 20 wt% WFC-blended mortar is 30% greater than that for ordinary mortar, indicating the improved structural integrity of the blended mortars. The WFC-blended mortars showed dense and compact microstructure confirming the improvement in the strength of mortars.
Arabian Journal for Science and Engineering, 2020
This study critically analyzes changes in land use and land cover by means of multi-temporal remo... more This study critically analyzes changes in land use and land cover by means of multi-temporal remote sensing of Najran City in Saudi Arabia between 1975 and 2019. A number of remotely sensed data were employed to create multi-maps using: (a) the normalized difference vegetation index; (b) head-up digitizing; and (c) supervised classification of Landsat images using field observation and accuracy assessment, including field verification and Google Earth Professional. Criteria from a wellknown technique of environmental assessment, the Building Research Establishment Environmental Assessment Method (BREEAM), were used to critically analyze land use and evaluate levels of sustainability, with particular focus on ecology. Therefore, land around Najran can be characterized as follows: (1) Najran valley; (2) agricultural land; (3) built-up areas; (4) reclaimed land; (5) basement rock; and (6) desert. The results indicate that agricultural land grew from an average of 39.81 km 2 (1.07%) in 1975 to 218.51 km 2 (5.9%) in 2005, although this was followed by a marked decline between 2005 and 2019. Urban land increased from 1.12 km 2 (0.031%) in 1975 to 154.35 km 2 (4.13%) in 2019. Furthermore, there was approximately 1289.47 km 2 of reclaimed land in 1975 (i.e., 34.64% of the total area study area) but approximately 1151.1 km 2 (30.86%) in 2019. There was a small amount of desert (i.e., sand dunes) in the study area, and no change was recorded in the basement rock. This study analyzed these land changes, likening them to BREEAM criteria of ecology and land use. A number of unsustainable practices were potentially resulting in serious land contamination and pollution of both surface and ground water, as well as an increased risk of flooding.
The Journal of Engineering, 2020
It has been claimed that the adoption of a smart and sustainable city concept is one of the most ... more It has been claimed that the adoption of a smart and sustainable city concept is one of the most effective ways to eliminate the risk of unsustainable living. Since the sixties, the Kingdom of Saudi Arabia was transformed from a country of traditional settlements to a modern urban setting. However, this development has been based on conventional methods of city construction and building practices. Therefore, the main aim of this primary research is to establish the fundamental aspects of developing a sustainable and smart city framework that can be applied to most Saudi Arabian cities and societies. A qualitative research methodology is adopted to determine end-user requirements, with more than 500 well-informed participants from 17 different cities. Subsequently, the main contributions here can be summaries as follows: (a) evaluating public willingness regarding smart sustainable city movements, (b) establishing requirements for a sustainable and smart city framework based on end-user perspectives, (c) providing a decision makers with a robust generic framework of sustainable development across Saudi Arabian cites, and (d) an Internet of Thing (IoT) architecture for SSC Adoption and implementation along with an integrated socio-organizational, financial, and technical generic framework for smart sustainable city adoption in the Saudi Arabian context.
Geotechnical and Geological Engineering, 2018
One hundred eighty-three rotary-drilled boreholes from fifteen districts in Najran area, Kingdom ... more One hundred eighty-three rotary-drilled boreholes from fifteen districts in Najran area, Kingdom of Saudi Arabia, were sampled and tested in the field and in laboratory to analyze the spatial variation in their geotechnical properties. Number of samples varied with the performed test including grain size distribution (668), Atterberg limits (24), moisture content (432), free swelling (49), direct shear strength (51), unconfined compression strength (37), and soil water chemistry of 168 samples were analyzed for Cl-, SO 3-2 , and CO 3-), and 120 samples for pH. Descriptive statistics were appraised for clarifying the geotechnical variations among the districts and various AASHTO-classified soil types. GIS-based geostatistical kriging with minimum error achieved was used for preparing the spatial maps of the geotechnical parameters. Results showed that majority of soil samples were non-plastic. Hubuna district showed the larger LL (42%), PL (25%), and PI (20%) while Mefraq Al-Khamis recorded the lowest values of LL (23%), PL (19%), and PI (2%). Atterberg limits showed a northwestward increase to reach its maxima at Thar. Moisture content was larget in Khobash and showed local highs at Najran Al-Fahd and Al-Mashaliya.Fine sands prevailed north and east of Abu Shadad with local highs in Al-Mashaliya and Najran University. Silt and clay soils dominate in Najran Al-Fahd district. Local highs of free swelling were vivid at Abu Shadad, Khobash, Mefraq Al-Khamis, and Najran Al-Fahd districts. UCS showed largest in Najran University. Shear test friction angle showed lowest at Khobash and Abu Shadad districts dominated by coarse to medium sands and gravels and largest of 35°in Najran University and extends to Thar attaining the largest fine sand and gravel contents. Largest Cland SO 3-2 contents characterized the districts of Thar, Al-Hosayniya and Hubuna while CO 3 showed local high at Najran Al-Fahd district, the soils were acidic with pH lower than 5.5. Three main soil types according to AASHTO classification formed about 91% of the samples: A-1-b (56%), A-2-4 (23.5%), and A-3 (11.4%), were mapped and their geotechnical properties were characterized. Results can help efficient decision-making process to set proper management zones and prevent geotechnical risks where measures in the design and construction stages can be decided for future expansions and subsurface tunneling based on the district-and soil type-specific.
Suez Canal Veterinary Medicine Journal. SCVMJ, 2015
The present study was aimed to determine the nematode parasites infesting cattle egrets (Bubulcus... more The present study was aimed to determine the nematode parasites infesting cattle egrets (Bubulcus ibis) and its role in maintenance of such parasites in nature or transmission of these parasites to other species of wild birds and domestic birds, mammals, fish and human being especially after dramatic increase of cattle egret's population inside the urban areas. During this study, a total of 106 cattle egrets (Bubulcus ibis) were examined and eight species of nematodes were detected. The detected species; Desportesius invaginatus (85.84%), Microtetrameres spiralis (67.92), Porrocaecum sp. (26.41%), Microtetrameres helix (23.58%), Tetrameres sp. (10.37%), Microfilaria (2.83%), Gnathostoma sp. larvae (1.88%) and Anisakis sp. larvae (0.94 %). Five factors (habitat, area of collection, sex, age and season) affecting the prevalence of nematodes in cattle egrets as well as the pathological effects of these parasites on cattle egrets were studied.
Suez Canal Veterinary Medicine Journal. SCVMJ, 2015
The present study was aimed to determine the ectoparasites infested the cattle egrets (Bubulcus i... more The present study was aimed to determine the ectoparasites infested the cattle egrets (Bubulcus ibis) and its role in maintenance of such parasites in nature or transmission of these parasites to other species of wild and domestic birds especially after dramatic increase of cattle egret's population inside the urban areas. During this study, a total of 106 cattle egrets (Bubulcus ibis) were examined for the detection of external parasites of which 5 species ectoparasites; two lice, one tick larvae, one flea and one dipteran fly were detected. The detected ectoparasites were two lice sprcies Ciconiphilus decimfasciatus (67.92%) and Menopon gallinae (45.28), one tick Argas persicus larvae (11.32), one fly Pseudolynchia sp. (9.43%) and one flea Ctenocephalides canis (1.88 %). Five factors (habitat, area of collection, sex, age and season) affecting the prevalence of these parasites in cattle egrets were studied. Introduction: Cattle Egrets (Bubulcus ibis) are common birds with a worldwide distribution. They forage in fields with cattle and other livestock and nest in dense colonies, often in urban areas (Telfair, 1993). Cattle egret shares the human habitat (Subramanya, 1996) and forage on wastes and garbage (Javed, 1983) and also feed on invertebrate and fish (Seedikkoya, 2003). It plays role in management of insect pests in different agro-ecosystems (Yadav, 2000). Wild birds harbor many species of ectoparasites such as lice, tick, mites, fleas and other blood sucking
Geotechnical and Geological Engineering, 2019
This paper deals with the geotechnical characterization of Sultana soils (Najran region, Saudi Ar... more This paper deals with the geotechnical characterization of Sultana soils (Najran region, Saudi Arabia) by in situ and laboratory tests, for a project proposal for the construction of commercial and government buildings. Geotechnical parameters of the subsoil were analyzed with a view to using the soil as an earth construction material and as a foundation for buildings constructed on the grounds tested. The site was investigated by means of boreholes, trial pits, standard penetration tests, plate load tests, Seismological data, particle size analyses, modified Proctor Tests, Oedometer and direct shear tests. The study contains full description to the subsurface soil conditions and provides recommendations for collapse potential, foundation type, foundation depth, allowable net bearing capacity, estimation for the expected settlement. In this paper a review of the principal results of the in situ and laboratory investigations is described. Results of the study revealed that within the maximum depth of 10.0 m of boring, the soil was found to be composed of brown soil mixture of sand and clayey silt with little gravel, classified as (SM) and (SC) according to USCS classification and as (A-2-4) and A-2-6 according to AASHTO classification. The area was found to consist in general of collapsible soils, classified as collapsible alluvial soils. The results show that the collapse potential of the majority of semi-arid soils tested were classified as severe trouble soils and natural moisture content is an important factor influencing the collapse potential of the soil. In addition, the results of this study provide the parameters to evaluate the soil behavior and the geotechnical model for the foundation bearing capacity and soil settlements evaluation.
Arabian Journal of Geosciences, 2018
The main objective of this study is to highlight the physical principles responsible for the smar... more The main objective of this study is to highlight the physical principles responsible for the smart characteristics/nature of the Al Masjid Al-Haram marble (MHM) as compared with the ordinary white marble (OWM). The main issue to address is the lack of experimental data and scientific discussion about the intelligent thermal performance of such a thin stone layer as natural cool material. For this purpose, various physical properties have been studied including the solar reflectivity and thermal conductivity; furthermore, X-ray diffraction (XRD), P-wave velocity Vp, and scanning electron microscopy (SEM) were performed to assess the crystalline quality, internal core structure, and the microstructure characteristics respectively. Results showed that the marble at Masjid Al-Haram is characterized with high thermal conductivity and superior solar reflectivity which help in dissipating the absorbed heat from environmental warm air and the incident solar radiation keeping it always cool. As compared with OWM, the MHM exhibited higher Vp which points to a pore-free characteristic of this marble. SEM micrograph revealed the well-arranged calcite crystals of MHM. XRD patterns indicated that calcite is the major mineral phase present in OWM; however, MHM was dolomite dominant.
Geotechnical and Geological Engineering, 2019
Many sources of data (remote sensing and meteorological data, soils and groundwater samples) were... more Many sources of data (remote sensing and meteorological data, soils and groundwater samples) were used to estimate the magnitude of geological hazards, which are confirmed with field and laboratory investigation in Najran area, Kingdom Saudi Arabia. Najran area is one of these locations. It is subjected to a range of geo-hazards due to its intrinsic physiographic and geologic nature. Najran area is a growing urban and agricultural development region; however, some infrastructures have been constructed in vulnerable locations to geo-environmental hazards. The potential geo-hazards that may occur under desert conditions include sand accumulations, dune movement, mass westing and rock fall hazards, flash floods, sand stroom and problematic soils. The current study throws more light on all these geo-hazards in Najran area. Also, remediation methods for geo-hazard should be proposed to avoid these natural hazards. The present study is a trail to calculate and evaluate the drainage basins properties and potentiality using remote sensing and (GIS) tools. Twenty morphometric parameters were measured, in order to identify and evaluate flash flood hazards. Flash flood hazards in the Wadi Najran watershed is classified into three groups based on their morphometric parameters results; namely, highly, moderately and low slightly hazard degree. Our findings indicate that Najran area needs more attention and care. The Saudi Government has to join together with other people to reduce the resulting geological hazards.
Geotechnical and Geological Engineering, 2017
The durability is a measure of the rock’s ability to resist degradation during its working life. ... more The durability is a measure of the rock’s ability to resist degradation during its working life. Rock durability is greatly related to the mineralogical composition of rocks, rock texture (crystal interlocking, crystal shape and size), and the nature of fluids that are in contact with rock. Marbles have been among the most important building materials since ancient times. The main aim of this study is to evaluate the durability of Al Masjid Al-Haram marble and Ordinary white marble “Carrara” (M1 and M2) and develop some correlations among the physical and mechanical properties such as P-wave velocity, slake durability index, dry uniaxial compressive strength (UCSDry), abrasion resistance, point load index, impact strength index, Brazilian tensile strength, and Shore hardness. After testing and the evaluation of the test results, strong statistical correlations were found between P-wave velocity and other rock properties. Statistical correlations between the UCSDry other tests were also carried out. The coefficients of regressions (R2) range from 0.6177 to 0.997. The study shows that the UCSDry values of M1 and M2 have positive relationship with P wave velocities. Concluding remark is that the rocks tested in the study have good durability characteristics and can be reliably used for construction projects. On the other hand, the derived empirical equations can be used for the estimation purposes for similar rock types.
Arabian Journal of Geosciences, 2017
Journal of Molecular and Engineering Materials, 2017
Marble has been widely used as building materials since ancient times. Abrasion resistance and sl... more Marble has been widely used as building materials since ancient times. Abrasion resistance and slake durability are the important characteristics of marbles. The prediction of these marbles properties will be useful from indirect methods especially for preliminary studies. In this study, the predictability of the Böhme abrasion resistance (BA) and the slake durability (SDI) of marbles were investigated from the indirect methods such as point load index ([Formula: see text], Shore hardness index (SHI), impact strength index (ISI), and ultrasonic velocity ([Formula: see text]). The evaluation of the test results showed that the SDI were correlated well to the [Formula: see text], and moderately correlated to the [Formula: see text]. But, the SDI was correlated weakly to both the ISI and SHI values. On the other hand, all indirect tests values were strongly or very strongly correlated to the BA values. Some multiple regression equations were also derived for the estimation of the SDI a...
Journal of Rock Mechanics and Geotechnical Engineering, 2017
Improvement of properties of weak soils in terms of strength, durability and cost is the key from... more Improvement of properties of weak soils in terms of strength, durability and cost is the key from engineering point of view. The weak soils could be stabilized using mechanical and/or chemical methods. Agents added during chemical stabilization could improve the engineering properties of treated soils. Stabilizers utilized have to satisfy noticeable performance, durability, low price, and can be easily implemented. Since cement kiln dust (CKD) is industrial by-product, it would be a noble task if this waste material could be utilized for stabilization of sabkha soil. This study investigates the feasibility of utilizing CKD for improving the properties of sabkha soil. Soil samples are prepared with 2% cement and 10%, 20% or 30% CKD and are tested to determine their unconfined compressive strength (UCS), soaked California bearing ratio (CBR) and durability. Mechanism of stabilization is studied utilizing advanced techniques, such as the scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), backscattered electron image (BEI) and X-ray diffraction analysis (XRD). It is noted that the sabkha soil mixed with 2% cement and 30% CKD could be used as a sub-base material in rigid pavements. The incorporation of CKD leads to technical and economic benefits.
Egyptian Journal of Petroleum, 2017
The aim of this study is to determine the mechanical and petrophysical properties of sandstone ro... more The aim of this study is to determine the mechanical and petrophysical properties of sandstone rocks and using P-wave to correlate among these properties as well as the influence of cement which are intrinsic factors controlling the mechanical properties of clastic rocks. The field study included the description of the Lower Red Unit of the Wajid Sandstone outcrop analog section described previously, lithofacies description, identification, and rock sample collection from the subsurface section. Both X-ray diffraction, SEM and petrographic analyses indicate that the red sandstones are composed of predominantly K-feldspar and quartz grains and an illite matrix. In the laboratory work; porosity (n%), permeability (K md), apparent density g/cc, water absorption (Ab%), void index (e%), Schmidt hammer rebound hardness (SHR), uniaxial compressive strength (rc MPa)), Point load index (Pl) and ultrasonic pulse tests (Vp) were carried out. Then, the results were analyzed statistically to find the correlation coefficient between these measured parameters. The results of Vp with the mechanical and physical properties of the rocks were analyzed using the method of least squares regression. In all cases, the weakly to moderately correlation coefficient (R 2) was determined for each regression. Relatively high correlation values were seen between Vp index and porosity of R 2 0.60. The sandstone in the study can be classified according to the UCS classification for intact rock into very low to low strength (1-20.39 MPa) and very low velocity of sound velocity classification.
Sustainability Science, 2014
Our built environment is responsible for some of the most serious global and local environmental ... more Our built environment is responsible for some of the most serious global and local environmental change. The construction industry, therefore, faces pressure to increase the sustainability of its practices reflected in the development of stringent regulations and environmental assessment methods, designed to mitigate such negative impacts. However, these well-known methods (e.g., BRE-EAM, LEED, SBTool, and CASBEE) have not originally been designed to suit developing countries (including Saudi Arabia). This paper proposes to customize an adapted weighting system that prioritizes Saudi environmental assessment method (SEAM) categories. The research methodology involves the use of analytic hierarchy process (AHP). Expert choice software was the main tool to analyze the input data. This research instrument involves the participation of a number of leading, global experts in the field of environmental and sustainable development, as well as professionals and highly informed local experts from government, academia, and industry. The results reveal that well-known environmental assessment methods are not fully applicable to the Saudi Arabia built environment, as reflected in the resulting categories, criteria and weighting system of SEAM.
Computing in Civil and Building Engineering (2014), 2014
The evolution of sustainable assessment tools created a competition amongst well-known tools towa... more The evolution of sustainable assessment tools created a competition amongst well-known tools toward international use. However, practical evidence shows that regional and sociocultural variations have been a strong obstacle to the direct use of those sustainable assessment tools. Hence this paper proposes to determine the applicable methodology supporting the adaptation of a sustainable building assessment method for any given region. The adaptation of the Saudi Environmental Assessment Method (SEAM) is taken in this paper as a subject of actual development. Because sustainable assessment tools involve multi-dimensional criteria, a mixed-methodology approach is used in conducting this study, given that the Delphi technique (DT) and analytical hierarchy process (AHP) have a proven record of reaching consensus by a panel of experts. Therefore, DT and AHP have been conducted; involving leading global experts in the domain of environmental and sustainable assessment schemes, as well as professionals and highly informed local experts from academia, government, and industry. The result shows that international sustainable assessment tools are not fully applicable to the Saudi built environment, as reflected in the development of a new building environmental and sustainability assessment scheme (SEAM).
Sustainable Cities and Society, 2012
Following expansion in the field of environmental assessment methods, existing methods cannot be ... more Following expansion in the field of environmental assessment methods, existing methods cannot be applied to all regions for a number of reasons, one of which is regional variation. This paper investigates the most important and globally widespread environmental assessment methods: BREEAM, LEED, SBTool, and CASBEE. It identifies areas of convergence and distinction in order to enable the consolidation of environmental criteria into new potential schemes. As well as considered a starting point for the procedure of consensus-based process, it also provides a generic model for the development of an effective environmental assessment method intended for the establishment of environmental assessment method suited to Saudi Arabia.
Renewable and Sustainable Energy Reviews, 2013
Scientific evidence suggests important discrepancies between simulated and real energy performanc... more Scientific evidence suggests important discrepancies between simulated and real energy performance of buildings. This is exacerbated in developing countries, such as Saudi Arabia, by the reliance on leading international building environmental and sustainability assessment schemes (e.g. BREEAM and LEED). The paper proposes to test the overarching hypothesis that the leading international environmental and sustainability assessment schemes are not adapted to the Saudi built environment, with a focus on the residential sector. The paper aims to (a) test the applicability of international leading schemes such as BREEAM and LEED for the assessment of Saudi's built environment, and (b) identify applicable building assessment categories and criteria for Saudi's built environment. As building assessment methods involve multi-dimensional criteria, a consensus based approach is used to conduct the research. Hence, the Delphi technique is selected and conducted in three successive consultation rounds involving world leading experts in the domain of environmental and sustainable assessment schemes, as well as professionals and highly-informed local experts from academia, government and industry. The results reveal that international assessment schemes are not fully applicable to the Saudi built environment, as reflected in the development of a new building environmental and sustainability assessment scheme.
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Papers by Ahmed Abd El-aal