Cost of Reinforced Concrete FRP Strengthening System and other Methods
Madeh Izat Hamakareem
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There are various techniques which are used to enhance both ultimate load capacity and serviceability of reinforced concrete structures. Strengthening reinforced concrete beams with FRP composite is the most novel method which has been developed. This method is widely accepted and has proven to be effective in improving capacity of reinforced concrete elements.
In this article, the economy of FRP strengthening systems in comparison with the cost of other conventional methods based on the conducted studies and projects will be discussed.
Fig.1: Reinforced concrete member strengthening using FRP composite (left side) versus strength using traditional methods (right side)
The economy of strengthening systems will be discussed in two stages which include:
Cost of Installation of FRP systems
Cost of Entire life service of strengthening systems installation of FRP systems
Cost of Installation of FRP Systems
The economy of FRP composite strengthening system at installation stage is based on the working conditions and factors that may involve the task.
Moreover, it is required to take the time frame allocated for completing the project and the available space at site when the cost of the work is evaluated. This is because these factors could have a substantial influence on the cost.
Furthermore, it is claimed that the cost of strengthening using FRP composite is around 70% of the total cost using other methods for strengthening. This claim is based on the study that conducted on the strengthening of rail track structure.
Installation cost estimation and studies on strengthening technique using FRP composite compare with other conventional methods
In certain projects such as high ways, closing of the structure for traffics would lead to penalty and hence increase the cost.
For instance, when main high way in New York City in the United States had to be upgraded, it was needed to do the work at night only because the high way needed to be open during the day otherwise a penalty of around thirty thousand US dollars would have been imposed for hour of high way closure in day.
There are number of projects for cost estimation has been carried out and all of them showed the superiority of strengthening technique using FRP over other ordinary or traditional methods.
For example a beam to column joint of parking garage structure enhanced by bonding carbine fiber sheet. It is found that, the use of such method needed around 35% of ordinary techniques which may involve the installation of additional reinforcement bars and pouring concrete as well.
In another project which located in Canada, the cost of shear strengthening of the entire bridge was estimated FRP sheet and steel stirrup. It was demonstrated that the cost of using FRP sheet was cheaper by about 30%.
As far as the installation time frame is concerned, there are cases in which the time needed to complete the strengthening project using FRP composite is substantially lesser that that needed when conventional method is employed.
For instance, the duration needed to strengthen a chimney in Japan was a month whereas the conventional method required six months. Finally, from the above examples, it can be concluded that, the cost of installation of FRP composite is considerable smaller than other traditional methods.
Cost of Strengthening Systems Installation of FRP Systems
The entire life service cost of strengthening technique is a major factor that plays significant role while a decision is made on how and when strengthens reinforced concrete structure.
Commonly, the enter life service cost of any strengthen system is composed of installation cost and maintenance cost that may be required during the life span of the structure.
However, since the installation cost has been discussed and accounted for, so the maintenance cost will be explored in this section.
When the entire life cost of strengthened structure is evaluated, it is necessary to take number of factors into account. For example, durability of strengthening technique, costs due to loss of service, requirements of the owner for serviceability and life service of the structure, and maintenance cost.
It is proven that, the cost of maintenance of reinforced concrete elements strengthened with FRP composite is smaller than that of reinforce concrete members strengthened with conventional methods.
Finally, it can be claimed that, the economy of using FRP composite systems to strengthen reinforced concrete structure is superior to other conventional method.