Papers by Yasser Alashker
Journal of Natural Fibers
Polymers
The large production of cement is resulting in a high-carbon footprint, which is essential to min... more The large production of cement is resulting in a high-carbon footprint, which is essential to minimize for sustainable concrete construction. Moreover, the large quantity of recycled coarse aggregate (RCA) from the demolition of old concrete structures is creating problems for landfill and disposal. The primary goal of this study is to investigate the seismic efficiency of innovative fiber-reinforced polymer (FRP)-recycled aggregate geopolymer concrete (RAGC) steel-tubed columns (FGSTCs) with an internal steel tube (STT), an external glass-FRP tube (GLT), and RAGC located between the two-tubed components to develop a serviceable structural element. To study their seismic functioning under axial load and lateral repeated load, five FGSTC specimens were manufactured and analyzed under quasi-static loads. The influence of three variables on the performance of FGSTC specimens, consisting of STT reinforcing ratio, compression ratio, and recycled coarse aggregate (RCA) replacement ratio, ...
Sustainability
In this study, the effect of micro-carbon fiber on the properties of concrete incorporating recyc... more In this study, the effect of micro-carbon fiber on the properties of concrete incorporating recycled coarse aggregate at three different levels, i.e., 0%, 50%, and 100% by volume replacement of natural coarse aggregate, was studied. Carbon fiber was incorporated at a dosage of 0.5% by volume fraction. The effect of silica fume or micro-silica on the efficacy of fiber reinforcement was also investigated. Studied parameters include important mechanical properties, such as compressive strength, splitting tensile strength, and flexural strength, and physical/quality parameters such as water absorption capacity and ultrasonic pulse velocity. The results showed that the mechanical and durability performance deteriorates with the increasing percentage of recycled coarse aggregate. Carbon fiber can significantly improve the tensile properties of recycled aggregate concrete. The combination of carbon fiber and silica fume proved to be highly useful in addressing both mechanical and durabilit...
Advances in Structural Engineering
A few empirical models for the axial loading capacity (ALC) of circular normal strength concrete ... more A few empirical models for the axial loading capacity (ALC) of circular normal strength concrete (NSC) columns wrapped by carbon fiber reinforced polymer (CFRP) sheets and interior transverse steel reinforcement (TSR) (CSC columns) are available in the literature. The deficiency of those models is that they were proposed based on a small number of tests by considering limited parameters of CSC columns. Therefore, the main aim of the current investigation is to propose the improved empirical models for the ALC of CSC columns by including the interaction mechanism between TSR and FRP confining behavior. To secure this aim, a general regression analysis technique and artificial neural networks (NNs) on the experimental outcomes of 76 CSC columns collected from the previous investigations were employed. The proposed NN model was adjusted for the different number of hidden layers and neurons to achieve an optimized model. The suggested NN and empirical models portrayed a close agreement ...
Frontiers in Environmental Science
The recent outbreak of epidemic disease (COVID-19) has dramatically changed the socio-economic an... more The recent outbreak of epidemic disease (COVID-19) has dramatically changed the socio-economic and environmental dynamics of the world. In particular, it affects human movement, travel intentions, and ambient air pollution amid rising stringency measures. Therefore, this study examines the influence of tourism knowledge, environmental vulnerability, and risk knowledge on travelers’ intentions in China’s tourism industry during COVID-19. To address the study objectives, an online survey questionnaire was created, through which a valid sample of 402 respondents was achieved. The direct and indirect relationship between variables was tested through structural equation modeling, the outcomes confirm that both tourism knowledge and risk knowledge in terms of COVID-19 significantly and negatively define the travelers’ intention toward tourism. Moreover, environmental vulnerability moderately affected tourism behavior and augmented with COVID-19 stringency disclosures. The mediating effect...
European Journal of Environmental and Civil Engineering
Journal of Building Engineering
Case Studies in Construction Materials
Recently the design of RC building to mitigate seismic loads has received a great attention. Sinc... more Recently the design of RC building to mitigate seismic loads has received a great attention. Since Saudi Arabia has low to moderate seismicity, most of buildings were designed only for gravity load. The objective of this paper is to analysis design RC building located in the most active seismic zone region in Saudi Arabia to mitigate seismic loads. A multi-storey reinforced concrete building, in Haql city, was seismically analyzed and designed using the Equivalent Lateral Force Procedure with the aid of SAP200 software. The chosen buildings which was Ordinary Moment Resisting Frame (OMR), was analyzed and designed by using SBC 301 (2007) Saudi Building Code [1], SAP2000 (structural analysis software) [2] and ISACOL "Information Systems Application on Reinforced Concrete Columns" [3]. The results showed that the current design of RC buildings located in the most active seismic zone region in Saudi Arabia, Haql city was found unsafe, inadequate and unsatisfied to mitigate se...
Civil Engineering Journal
Background: The designing of the reinforced concrete building for the reduction of the seismic lo... more Background: The designing of the reinforced concrete building for the reduction of the seismic load has significantly gained popularity. Most of the buildings in Saudi Arabia are designed for the gravity load, based on its seismicity level. Objective: The study evaluates the effects of the earthquake load on the RC school building located in Saudi Arabia. Method: An equivalent static analysis technique used to apply the seismic analysis and design method according to Saudi Building Code SBC301 (2007). This design code is used to redesign the chosen school building. The SAP 2000 structural analysis software was used to analyses and study the structure behaviour due to the seismic load. Results: The results of the study provide that the RC school building design in Saudi Arabia is inadequate, and unsafe for the earth quakes. Conclusion: One of the important conclusions in this study is that the designer of the school building in Saudi Arabia should take into consideration the earthqua...
Open Journal of Civil Engineering, 2015
In the recent earthquakes, concrete structures have been severely damaged or collapsed, which has... more In the recent earthquakes, concrete structures have been severely damaged or collapsed, which has raised questions against the seismic adequacy of existing buildings. These existing reinforced concrete buildings need to be evaluated to determine the capacity to resist seismic loads. The behavior of a building during earthquakes depends critically on its overall shape, size and geometry. Conventional approach to earthquake resistant design of buildings depends upon providing the building with strength, stiffness and inelastic deformation capacity which are great enough to withstand a given level of earthquake-generated force. This is generally accomplished through the selection of an appropriate building configuration and the careful detailing of structural members. In this research, nonlinear pushover analysis has been used to evaluate the seismic performance of three buildings with three different plans having same area and height. This method determines the base shear capacity of the building and performance level of each part of building under varying intensity of seismic force. The results of effects of different plan on seismic response of buildings have been presented in terms of displacement, base shear and plastic hinge pattern.
Journal of Geographic Information System, 2014
This study investigates the potential for remote sensing of lake water bathymetry and geochemical... more This study investigates the potential for remote sensing of lake water bathymetry and geochemical by 1) examining the empirical based technique for retrieving depth information from passive optical image worldview-2 satellite data, 2) performing atmospheric correction, 3) assessing the accuracy of spectrally based depth retrieval under field condition via field measurement, 4) producing bathometry and geochemistry mapping by examining spectral variations for identifying pairs of wavelengths that produce strong linear correlation coefficient between the band ratio. The results indicate that optical remote sensing of bathymetry and geochemical investigation is not only feasible but more accurate under conditions of typical lake water, supporting field survey. The Pearson correlation matrix (R) between the examined water samples/depth and the TOA reflectance values of the worldview-2 (WV-2) satellite data have been investigated and found good correlation. The models developed using the combination of different band pairs also show high
Journal of Structural Engineering, 2011
Journal of Structural Engineering, 2011
Journal of Structural Engineering, 2010
ABSTRACT This paper discusses the progressive collapse resistance of steel-concrete composite flo... more ABSTRACT This paper discusses the progressive collapse resistance of steel-concrete composite floors in which steel beams are attached to columns through shear tabs. This is a common type of system used for the gravity bay portions of steel buildings. The study is conducted using computational simulation models validated through extensive comparisons to disparate test data. The models are used to investigate key parameters influencing the robustness of generic composite floors subjected to the removal of a center column. In particular, the effects of deck thickness, steel reinforcement, and the numbers of bolts in the shear tab connection on the behavior of the system are studied as a function of the loading scheme. The simulation results show that the majority of collapse resistance comes from the steel deck and that, for the system considered, increasing connection strength by adding more bolts might not be that beneficial in increasing overall collapse strength. The dynamic impact factor, which is widely used to account for dynamic effects within a static design framework, is also computed and the DIF value recommended in existing design guidelines is evaluated.
Geocarto International, 2014
ABSTRACT Taylor & Francis makes every effort to ensure the accuracy of all the informatio... more ABSTRACT Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access
Journal of Constructional Steel Research, 2011
A design-oriented model is proposed for computing the load-resisting capacity of composite steelc... more A design-oriented model is proposed for computing the load-resisting capacity of composite steelconcrete floors subjected to interior column loss. The model is based on the premise that floor collapse is resisted through the development of membrane action in the slab elements and catenary forces in the steel beams. A number of simplifying assumptions are made in the model pertaining to the deformed shape of the system, development of failure-resisting mechanisms, and overall system behavior. The proposed model is incremental in nature and tracks the evolution of damage in a floor system loaded up to failure. The model is shown to be able to capture the effect of influential variables on collapse resistance. Key limitations on the model are highlighted and discussed.
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Papers by Yasser Alashker