Life cycle cost (LCC) analysis is currently a most valuable tool in the civil engineering construction industry and will be inevitable as resources become scarce. Selection of materials for fabricating components of any civil engineering structures will be based on LCC analysis. It is due to significant reduction in lifetime cost of construction, maintenance, repair and rehabilitation. In this paper, cost benefit analysis of three types of beam namely Glass Fiber Reinforced Polymer (GFRP) reinforced, epoxy coated and steel reinforced beam was done. It includes the calculation of total lifetime cost, overall system cost and calculation the Net Present Value (NPV). Beams with over reinforced section and under reinforced section were considered in the cost analysis to have better understanding. A comparison was made between steel reinforced beam and GFRP reinforced beam to assess the benefits based on the economic aspects. From the results, it was found that good amount of cost-saving to an extent of 20% at initial stage and 40% with increase in age for GFRP reinforced beam over steel reinforced beam. The trend in variation of total cost for GFRP reinforced beam was consistent throughout its lifetime, whereas for steel reinforced beam and epoxy coated beam it was not so. Hence with the combined advantages of structural performance, serviceability, suitability for aggressive environments and economy, GFRP reinforced beam was strongly recommended from this study.

This paper explains an experimental research program on the use of GFRP (Glass Fiber- Reinforced Polymer) for retrofitting small-scale slender R/C columns to enhance seismic performance. An important deficiency in many existing nonductile reinforced concrete frames is the inability of the columns to undergo significant deformations while maintaining their load-carrying capacity. As a result, relatively brittle modes of column failure, accompanied by soft storey structural failure mechanisms, are possible. Providing additional confinement to the columns allows them to behave in a more ductile manner.In this study, six 1/2-scale columns were constructed and tested under cyclic loading to examine the effectiveness of the retrofitting technique for improving the seismic resistance of slender concrete columns. Three columns were tested after being retrofitted with GFRP wraps at the potential plastic hinge zone, while three others were tested in the “as-built” condition. One of the “as-built” specimens was constructed according to ACI (318-02) detailing and five others were built in accordance with ACI (pre.1971). In general, the common mode of failure for the “as-built” samples was a brittle failure due to bond deterioration of the lap-spliced longitudinal reinforcement. Test results suggest that GFRP wraps can significantly increase the flexural strength and ductility of slender rectangular reinforced concrete columns.

The performance of concrete structures is affected by the transfer of force between rebar and concrete, which depends on factors such as concrete strength, yield stress, rebar geometry, rebar diameter, concrete cover and splice length. Also, the use of reinforced polymer materials has become popular due to their successful application in structure. In this study, the effect of various factors on the bond strength of glass fiber-reinforced polymer bars, used in concrete beams, is evaluated and the accuracy of the equations proposed by different regulations and researchers is investigated. To investigate the effect of different factors on bond strength of glass fiber-reinforced polymer, the results of 43 tests conducted by different researchers have been used. Factors studied on the bond strength include the effect of the surface shape of the reinforcement, concrete strength, the amount of concrete cover on the bar, the splice length and transverse reinforcement. After examining the effect of various factors, the accuracy of the equations provided by regulations and researchers in determining the bond resistance for these laboratory results, the accuracy and standard deviation of each equation is evaluated. The results showed that increasing the compressive strength of concrete in samples without stirrup increases the bond strength, and in samples with stirrup, it has no effect on the bond strength. Also, the majority of existing equations estimate the amount of bond strength more than the values obtained from experiment results.

Given the problems and disadvantages of fiberglass vessels during and after the construction and during the operation at sea, this paper first examines the problems in manufacturing process and suggests appropriate solutions and strategies for solving them. Then, issues like repairmen and inspection are assessed. Advantages of fiberglass vessels over others are also presented.

An experimental study on the flexural behavior of reinforced concrete (RC) arches strengthened with glass fiber-reinforced polymer (GFRP) layers is performed. Totally, 36 specimens including 3 un-strengthened (control) and 33 strengthened RC arches were tested under centrally concentrated point load. The variables of this study were the steel reinforcement ratios, number of GFRP layers, and location and arrangement of GFRP layers. The failure mode, load-displacement response of specimens, crack propagation patterns, and GFRP debonding were examined. The extrados strengthening method was more effective than intrados strengthening approach in improving the failure load and rigidity of the arches. However, applying excessive GFRP layers at extrados can change the failure mode of arches from flexural to shear failure. The dominant failure mode of specimens was flexural and ductile failure due to the formation of five-hinge mechanism. Generally, GFRP strengthening could augment the ultimate load carrying capacity, secant stiffness, and energy absorption capacity of arch specimens by up to about 154, 300, and 93 percent, respectively. Statistical analyses were performed to assess the level of influence of each considered parameters on the behavior of RC arches. Finally, Analytical approach predicts the experimental data on arches with five-hinge failure mechanism satisfactorily.

This paper illustrates the finite element modeling of concrete columns with and without GFRP (Glass Fiber Reinforced Polymer) wraps. A series of Finite Element models were developed for pushover analysis. Two of them were built according to Iranian code (ABA) detailing and the rest of them according to ACI 318-Pre 71 detailing. Half of the models are assumed to be wrapped by FRP.The analysis was a displacement control analysis with a 5 cm displacement applied at the top of the column, with various ratios of axial load, from 0.05 Agf'c to 0.25 Agf'c. The analysis resulted in a force displacement capacity envelope of retrofitted and unretrofitted columns. Only parts of the bottom of the columns were wrapped up to the recommended splice length of the bars.It is shown that applying GFRP can increase the ductility, as well as the flexural strength, of the RIC columns. Also, a comparison between analytical and experimental results implies that the proposed modeling can be used with sufficient accuracy.

This paper presents an experimental study on seismic repair of damaged square reinforced concrete columns with poor lap splices, 90-degree hooks and widely spaced transverse bars in plastic hinge regions according to ACI detailing (pre.1971) and (318-02) using GFRP wraps. Three specimens were tested in “as built” condition and retested after they were repaired by glass fiber-reinforced plastic sheets. They were tested under numerous reversed lateral cyclic loading with a constant axial load ratio. FRP composite wraps were used for repairing of concrete columns in critically stressed areas near the column footings. Physical and mechanical properties of composite wraps are described. Seismic performance and ductility of the repaired columns in terms of the hysteretic response are evaluated and compared with those of the original columns. The results indicated that GFRP wraps can be an effective repair measure for poorly confined R/C columns due to short splice length and widely spaced ties with 90-degree anchorage hooks. Both flexural strength and ductility of repaired columns were improved by increasing the existing confinement in critical regions of them.

Milling of fiber reinforced polymer composites is of great importance for integrated composites with other mating parts. Improper selection of cutting process parameters, excessive cutting forces and other machining conditions would result in rejection of components. Therefore, machining conditions are optimized to reduce the machining forces and damages. This work reports practical experiments in milling, to study the effect of machining conditions on cutting force, surface roughness and damage factor of Glass Fiber Reinforced Polymer (GFRP) composites. The experiments were carried out with a designed carbide end mill tool by a random set of milling process parameters. The results showed that machined surface integrity was highly influenced by the spindle speed followed by the feed rate. The results of the experiments were illustrated and analyzed by interaction plots and Scanning Electron Microscope (SEM) images.