International Concrete Abstracts Portal

The Naval Facilities Engineering Service Center (NFESC) investigated a hull concept for a proposed floating pier with a design life of 100 years. The hull concept consists of bidirectional post-tensioned lightweight concrete panels reinforced with carbon fiber reinforced polymer (CFRP) grids for crack control and toughness. CFRP grid reinforcement could be a potential durable alternative to using stainless steel reinforcement and could be cost-effective for marine application, if the use of CFRP reinforcement justifies minimizing the concrete cover and allowing minor cracking during service load. The paper discusses construction and cost considerations developed during production of 13 testing specimens of such a panel concept. Though the panel concept seems feasible, the NFESC deferred the concept for the time being due to the high cost of CFRP, the difficulties in detailing panel connections using CFRP reinforcement, and the unknowns related to the durability of CFRP reinforcement in cracked concrete exposed to marine environment.

Fiber reinforced polymer (FRP) materials can be used in concrete infrastructure elements to achieve short-term and long-term construction and performance goals that cannot be met with traditional steel reinforcement. Like other states, Texas is faced with materials-based transportation infrastructure challenges including: deterioration of concrete due to the corrosion of steel reinforcement, bridge girders damaged by vehicle impacts, concrete bridges that have no visual signs of distress but are load-posted or otherwise deficient in load rating, girders and bent caps that have inadequate shear reinforcement by current standards or that exhibit service cracking, and even a need to provide reinforcement that does not interfere with vehicle imaging loops requiring magnetic/electrical isolation near turnpike toll plazas. This paper reports on Texas transportation infrastructure construction and maintenance projects where FRP materials have been implemented as a means to meet each of these challenges. Included herein are descriptions of selected Texas Department of Transportation (TxDOT) construction and maintenance projects involving concrete internally and externally reinforced by FRP materials. These projects are either completed or will soon go to contract. Most of these projects have been carried out on a trial or experimental basis but they serve to provide a brief glimpse into the probable future of FRP reinforcement in Texas transportation projects.

A new highway bridge was constructed using FRP bars as reinforcement for the concrete deck slab. The bridge, located on highway 55 North over the Magog River (Quebec, Canada), is a girder type with a total length of 83.7 m and five main steel girders continuously supported over three spans. The two end spans are 26.2 m each and the middle one is 31.3 m. The deck is a 220-mm thickness concrete slab continuous over four spans of 2.845 m each with an overhang of 1.352 m on each side. One full end span (26.2 m) was totally reinforced with FRP bars in top and bottom mats. The other two spans of the bridge were reinforced with galvanized steel. The steel reinforced concrete deck slab was designed according to Section 8 of the New Canadian Highway Bridge Design Code, CHBDC (CAN/CSA-S6-00 2000). The steel reinforcement was then replaced with FRP bars according to Section 16 of CHBDC (CAN/CSA-S6-00 2000). This design resulted in using glass FRP bars (No.16 - 15.9 mm-diameter) in all directions except in the transverse direction on the bottom mat where carbon FRP bars (No. 10 - 9.5 mmdiameter) were used. The construction of the bridge was completed on September 2002 and opened for traffic during the second week of October 2002. Before opening to the traffic, the bridge was tested for service performance using standard truckloads as specified in the new CHBDC (CAN/CSA-S6-00 2000). During all load tests, strains in FRP and steel reinforcements and deflections of FRP and steel reinforced spans (slabs and girders) were recorded. Design, construction details, and the results of this first series of field tests are discussed in this paper.

SP-215 The field application of fiber-reinforced polymer (FRP) composite materials as reinforcement for concrete structures has been growing rapidly in recent years, mostly with interest in alternatives to steel reinforcing bars and for strengthening concrete structures. FRP products provide options and benefits not available using traditional materials. As a result of the extensive use of FRP as internal and external reinforcement for new structures and strengthening concrete structures, respectively, ACI Committee 440 organized three technical sessions on “Field Application of FRP Reinforcement—Case Studies” with a total of 21 papers presented at the ACI Fall 2003 Convention in Boston, Mass. All papers deal with case studies and demonstration projects to provide clear evidence of the practicality, credibility, and maturity attained by this technology. This volume includes the papers presented during the Fall 2003 Convention, plus five additional papers that augment the range of field applications and case studies. The goal of this document is to help practitioners implement FRP technology, while providing testimony that design and construction with FRP material systems is rapidly moving from emerging to mainstream technology.

The earthquake of June 23, 2001, that affected most of the southern part of Peru, put in evidence the seismic vulnerability of icons of the cultural heritage of the country. The historical downtown of the city of Arequipa (located at 1000 km to the South of Lima) was heavily affected by the earthquake, with forty percent of its representative buildings suffering damage ranging from moderate to severe with partial collapse. The towers of the cathedral of Arequipa, built integrally with a volcanic stone called sillar, suffered extensive damage. As a consequence, the left tower partially collapsed, whereas, the right tower remained standing but in an unstable condition. This paper describes the reinforcing strategy of the right tower with Carbon Fiber Reinforced Polymer (CFRP) laminates, which were used to provide tensile strength and confinement to the central stone core of the tower. After completing the CFRP installation, carved stones were placed on top of the laminates to keep the original appearance.