Development and evaluation of glass fiber-reinforced composite/wood railroad crossties

Laosiriphong, Krit

doi:10.33915/etd.1080

Cited by 6 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…He developed more accurate environmental reduction factors than those given by the design codes. Laosiriphong (2000) found that the use of GFRP wraps increased the durability of railroad crossties and enhanced the flexural rigidity by 44% and the shear modulus by 18%. Memon and Sheikh (2005) investigated the use of GFRP sheets to repair square columns under simulated earthquake loads.…”

Section: Fig 4 Schematic Of Damaged Sectionmentioning

confidence: 99%

Rehabilitation of a Vehicle Impact Damaged Concrete Bridge Girder with GFRP Rebars

Yazdani

Montero²

2018

MATEC Web Conf.

View full text Add to dashboard Cite

Overpass bridge girders are susceptible to impact damage of over-height vehicles, creating a traffic hazard and structural deficiency. The repair for a damaged girder has to meet adequate criteria for the safety, repair time and economy. This paper presents a case study for the repair of such an impact damaged concrete girder on the Lyndon B. Johnson Express construction project, located on I-635 and I-35 freeways in Dallas, Texas. The impact caused concrete loss and exposed several restressing strands on the exterior girder. The overpass had been completed while the old route was open below, causing a temporary vertical lower clearance than the final design, leading to the impact. The novel and innovative repair process involved fiber glass (GFRP) rebars, bonding epoxy and repair mortar. These rebars enhanced the flexural capacity of the repaired section and supplemented the mortar strength. Onsite load testing was employed to verify the performance of the repaired structure. Theoretical model of the composite girder before and after repair was employed. The strain data from the model compared well with the load testing data. The repair scheme drastically increased the stiffness of the damaged girder, resulting in about 50% reduction in the bottom strains. The beneficial effect of the repair resulted in large increases in the net compressive stresses (200–300%) at the girder bottom through the increase of the section stiffness and reduction of the gravity load stresses. Stresses remained well below the elastic range for concrete and the GFRP rebars.

show abstract

Section: Fig 4 Schematic Of Damaged Sectionmentioning

confidence: 99%

Rehabilitation of a Vehicle Impact Damaged Concrete Bridge Girder with GFRP Rebars

Yazdani

Montero²

2018

MATEC Web Conf.

View full text Add to dashboard Cite

show abstract

“…Yan [31] investigated the durability of GFRP as bridge deck reinforcement subject to weathering conditions. Laosiriphong [18] found that the use of GFRP wraps increased the durability of railroad crossties and enhanced the flexural rigidity by 44 % and the shear modulus by 18 %. Memon and Sheikh [20] investigated the use of GFRP sheets to repair square columns under simulated earthquake loads.…”

Section: Introductionmentioning

confidence: 99%

Structural performance of impact damaged and repaired concrete bridge girder using GFRP rebars

Yazdani

Montero²

2016

Innov. Infrastruct. Solut.

View full text Add to dashboard Cite

Overpass bridge girders are susceptible to impact damage of over-height vehicles, creating a traffic hazard and structural deficiency. The repair for a damaged girder has to meet adequate criteria for the safety, repair time and economy. This paper presents a case study for the repair of such an impact damaged concrete girder on the Lyndon B. Johnson Express construction project, located on I-635 and I-35 freeways in Dallas, Texas. The impact caused concrete loss and exposed several prestressing strands on the exterior girder. The overpass had been completed while the old route was open below, causing a temporary vertical lower clearance than the final design, leading to the impact. The novel and innovative repair process involved fiber glass (GFRP) rebars, bonding epoxy and repair mortar. These rebars enhanced the flexural capacity of the repaired section and supplemented the mortar strength. Onsite load testing was employed to verify the performance of the repaired structure. Theoretical model of the composite girder before and after repair was employed. The strain data from the model compared well with the load testing data. The repair scheme drastically increased the stiffness of the damaged girder, resulting in about 50 % reduction in the bottom strains. The beneficial effect of the repair resulted in large increases in the net compressive stresses (200-300 %) at the girder bottom through the increase of the section stiffness and reduction of the gravity load stresses. Stresses remained well below the elastic range for concrete and the GFRP rebars.

show abstract

“…However, Talakanti [22] showed that under a maximum applied strain of 4500 microstrains, after 2 million fatigue cycles, a GFRP wrapped wood specimen retains about 60% stiffness while an unwrapped wood specimen fails at 0.5 million cycles. Work currently in progress, being done by researchers at the Constructed Facilities Center (Chamarthy [23] and Laosiriphong [24]) also showed that the GFRP wrapping increases the properties of wood upto 100%. We speculate that The following observations were made from Figure 6.6:…”

Section: Sample Conditioningmentioning

confidence: 99%

Manufacture and rehabilitation of guard-rail posts using composites for superior performance

Anegunta¹

View full text Add to dashboard Cite

The objective of this research was to study the effectiveness of an external composite reinforcement in increasing the strength and durability of a conventional CCA treated wood post. Glass fibers (with excellent mechanical properties and low cost) in a polymer matrix were used for wrapping CCA treated wood posts. Six chemically different resins were screened, and a combination of HMR (Hydroxy Methylated Resorcinol) as primer and epoxy as adhesive was found to provide the best possible adhesion of the wrap to CCA treated wood. Wooden posts of 0.5 OD and wrapped posts of 0.6 OD, representing a scaled down version of the proposed posts were subjected to a 6-cycle aging procedure that involved application of vacuum and pressure under water. The wrapped posts were also subjected to freeze-thaw cycling in four different liquid media: (1) water (2) 3% salt water (3) acidic solution of pH 3 (4) alkaline solution of pH 13. The retention of flexural strength and stiffness of the wrapped posts after chemical aging was measured. Samples of dimensions 50 mm X 9 mm X 2 mm wrapped with 1mm thick wrap were also subjected to aging. The retention in strength and stiffness was measured and the service life was estimated. Results of flexure tests show that the strength of the wrapped post reduces due to aging. Results of DMTA (Dynamic Mechanical Thermal Analysis) show that freeze-thaw cycling and 6-cycle aging increase the Tg (glass transition temperature) and widen the glass transition region. After a service life of about 20 years, the stiffness of a wrapped post is predicted to be about 1.8 times that of an unwrapped wood post of the same age. Heating and freezing in liquid media causes more damage than heating and freezing in the absence of a liquid medium. Among the liquid media, it was found that the alkaline medium damages the epoxy matrix, the epoxy/glass interface and also the wood/HMR/epoxy bond. Acid medium primarily damages the epoxy/glass interface. Water diffuses easily through the epoxy matrix and primarily damages the epoxy/glass interface. Salt water damages the wood/HMR/epoxy bond. The performance in terms of flexural strength, modulus and rigidity was reduced the most by acidic medium, and the least by saltwater medium. There was no delamination at the wood/FRP interface under any of the aging conditions. It was concluded that under unaged conditions, the flexural rigidity of wood is improved by 162% due to composite wrapping. The technique of composite wrapping also shows a promise of improving the properties of guard-rail posts under actual field conditions. v

show abstract

Development and evaluation of glass fiber-reinforced composite/wood railroad crossties

Cited by 6 publications

References 0 publications

Rehabilitation of a Vehicle Impact Damaged Concrete Bridge Girder with GFRP Rebars

Rehabilitation of a Vehicle Impact Damaged Concrete Bridge Girder with GFRP Rebars

Structural performance of impact damaged and repaired concrete bridge girder using GFRP rebars

Manufacture and rehabilitation of guard-rail posts using composites for superior performance

Contact Info

Product

Resources

About