Saud A. Gutub

A review on FRP composites applications and durability concerns in the construction sector

Construction sector is one of the largest markets for fibre reinforced polymers (FRPs) globally. FRP composites are used in a wide range of applications in construction ranging from rehabilitation of existing structures to the full-scale use for new projects because of the benefits they provide over conventional building materials. Such advantages include but not limited to lightness, high mechanical performance and possibility of production in any shape, ease of installation and lesser requirement for supporting structure, controlled anisotropy, high specific strength and specific stiffness. All these multifarious features of FRPs are knocking the doors for new avenues of myriad applications in the Construction Industry, but unfortunately polymeric composites are susceptible to heat and moisture when operating in changing environmental conditions dispelling the biggest myth of them being invincible. The heat response of FRPs is also a major issue of importance in dictating the fate of FRPs future acceptability and applicability. This paper thus attempts to review the specific areas of the current utilization trend of FRPs in the Construction Industry and draw their advantages to support the future applications in a variety of construction processes. It is also being attempted to juxtapose the applicability and the durability concerns of FRPs in a single literature for assessing the versatility and scope of FRPs, by shedding light on the past available studies on the related matter.

Assessment and Analysis of Wind Power Resource Using Weibull Parameters

In this study, wind data of eleven years (2002–2012) has been used to determine wind characteristics of Saudi Arabian city Jeddah. These characteristics include the daily, monthly and annual wind speed, wind probability density distribution, shape (k) and scale (c) parameters at 10 m height. The analysis revealed that yearly values of k ranged from 1.398 to 1.763 with a mean value of 1.590 and values of scale parameter c varied from 3.146 to 4.329 with mean value of 3.95. Furthermore, the results showed that maximum and minimum wind power potential was observed in the month of March and February, respectively. The wind was found to be blowing predominantly from south east direction. It was found that wind potential of the region can be used for small scale off-grid wind applications.

Materials Selection Strategy and Surface Treatment of Polymer Composites for Wind Turbine Blades Fabrication

In the present work the optimal materials selection for wind turbine blades using the Cambridge Engineering Selector (CES) program was carried out. Materials indices were derived, based on the mechanical, physical properties and environmental circumstances. Glass and carbon fibre reinforced plastics (epoxy matrix) showed high materials indices based on combined analysis of power and efficiency, fracture toughness, fatigue and thermal stability. Epoxy-glass fibre (EGF) and epoxy-carbon fibre (ECF) composites were manufactured and investigated. Surface of glass and carbon fibre was chemically modified using gamma-aminopropyltriethoxysilane (Silane A1100) coupling agent. The fibre content was varied between 12 to 70% w/w. It is found that the addition of (Silane A1100) as a compatibilizer caused further amelioration of the fibre/matrix bonding resulting in improved mechanical behaviour, which was also, assessed using scanning electron microscopy. Mechanical properties of treated and untreated epoxy composites were illustrated using CES program. Tensile strength of EGF composites was varied based on fibres surface treatment and loadings. Tensile strength of silane treated EGF (70% wt/wt) increased to 1.46 GPa comparing with 1.38 GPa of untreated EGF. The potential and applications of this class of composite materials promise a significant opportunity for improving structural properties of wind turbine blades.

Sustainability and human health issues pertinent to fibre reinforced polymer composites usage: A review:

The specific properties of fibre reinforced polymers give them a lot of advantages over traditional materials but the long life of polymeric composites poses serious environmental threats raising sustainability concerns. The other issue of importance concerning the innovators and environmentalists in the mass usage of this material is its health impacts on human beings. This paper thus attempts to highlight and surface out the issues related to fibre reinforced polymers’ sustainability and their health impacts on human beings, by reviewing past studies on the subject, to examine critically the extensive body of published data, prior observations and ideas on the subject in order to identify and analyse those features that are intrinsic and unique to fibre reinforced polymers. This would thus serve as a conceptual model for future research on fibre reinforced polymer composites sustainability and health concerns.

Earthquake Induced Pounding-Involved Response of Base-Isolated Buildings Incorporating Soil Flexibility

This research aims to get some insight into the influence of supporting soil on the seismic response of base-isolated buildings impacting with the neighbouring retaining wall. Two ground motion records from two different regions are used as excitations. A nonlinear impact model is incorporated to capture the pounding force. In addition, an efficient discrete-element model is applied to represent the rotational and horizontal movements of the soil. The dynamic response of the isolated building resting on different flexible base soils and hits the adjacent abutment and the corresponding response of the building resting on a rigid base soil are presented. Analysis of the results expressed in the form of time-history and peak response for various values of structural natural periods, gap sizes, and base-isolated periods is carried out. The results show a considerable influence of the simultaneous effect of base-isolated pounding and base soil flexibility on the dynamic response of isolated buildings during earthquakes.

Removal of Cyanide from Liquid Waste by Electrochemical Oxidation in a New Cell Design Employing a Graphite Anode

Removal of CN− from liquid solutions was studied experimentally by an anodic oxidation technique under various operating conditions. A new cell configuration was used, the cell consists of four vertical graphite rod anodes distributed at 90° on the circular circumference at a distance of 3 cm from the wall and surrounded by two cylindrical stainless steel screen cathodes from the inner and the outer side. Parameters investigated are the initial concentration of cyanide ions, applied current density, initial pH of the electrolyte, and electrolyte conductivity. All parameters were investigated at an operating time of 3 h. The % removal increased upon increasing the applied current density, increasing the electrolyte conductivity, and decreasing the initial concentration of CN−. Increasing initial pH from 4 to 8 increased the % removal by a factor ranging from 55 to 73%, further increase of pH up to 12 slightly increased the % removal (3–8%). Application of the present electrochemical reactor in treating cyanide containing effluents from different industries was highlighted.

Reconstruction of flash flood victims lost residence utilizing lightweight sandwich composite technology

Traditional building materials may not be appropriate in view of the urgency in dealing with flash flood victims which need for immediate replacement of destroyed housing at a reasonable cost. Thus, the solution lies in making the best use of lightweight sandwich composite technology for flash flood victims lost residence in a short time. Therefore, this research focuses on comprehensive comparisons in bending of LWF sandwich/concrete (RC) composite beams. The flexural response of the LWF/RC beams is investigated in terms of crack load, load–deflection curves, stiffness, energy absorption capacity, ductility index, ultimate flexural load-to-weight ratio, load–strain curves, crack patterns, number of cracks, average crack width, crack spacing, and the failure mode. The test results reveal the remarkable enhancement in the flexural behavior and potential application for reconstruction of flash flood victims lost residence utilizing lightweight sandwich composite technology. The method outlined by ACI Building Code is used to compute ultimate moment capacities. The results obtained using this method are compared with the experimental results.