Fiber Reinforced Polymer Culvert Bridges—A Feasibility Study from Structural and LCC Points of View

Soil–steel composite bridges (SSCB) have become increasingly popular for short-span bridges as an alternative to concrete slab bridges mainly due to their low initial cost, rapid manufacture, simplified construction, and geometrical adaptability. SSCBs have a variety of applications and can be used over waterways or roadways. While conventional bridges tend to lose their load-carrying capacity due to degradation, SSCBs gain strength because of backfill soil consolidation. However, the load carrying capacity and integrity of such structures highly depends on the condition and load-carrying capacity of the steel arch element. A major drawback of SSCBs, especially those located on waterways or with poor drainage, is corrosion and subsequent loss of cross-sectional capacity. Unfortunately, the inspection of such bridges is not straightforward and any damage/collapse will be very costly to repair/replace. Fiber reinforced polymer (FRP) composites offer an attractive alternative to replace the steel in these types of bridges. FRP composites have significantly improved durability characteristics compared to steel, which will reduce maintenance costs and improve life-cycle costs (LLCs). This paper presents a new concept to use glass FRP as a construction material to construct soil–FRP composite bridges (SFCB). Various aspects of design and manufacturing are presented along with results and conclusions from a case study involving alternative bridge designs in steel and FRP composites.

Comparative Life Cycle Analysis of Concrete and Composite Bridges’ Varying Steel Recycling Ratio

Achieving sustainability is currently one of the main objectives, so a consensus between different environmental, social, and economic aspects is necessary. The construction sector is one of the main sectors responsible for environmental impacts worldwide. This paper proposes the life cycle assessment (LCA) and comparison of four bridge deck alternatives for different span lengths to determine which ones are the most sustainable solutions. The ReCiPe method is used to conduct the life cycle analysis, by means of which the impact value is obtained for every alternative and span length. The Ecoinvent 3.3 database has been used. The life cycle has been divided into four phases: manufacturing, construction, use and maintenance, and end of life. The associated uncertainties are considered, and the results are shown in both midpoint and endpoint approaches. The results of our research show that for span lengths less than 17 m, the best alternative is the prestressed concrete solid slab. For span lengths between 17 and 25 m, since the box-girder solution is not used, then the prestressed concrete lightened slab is the best alternative. For span lengths between 25 and 40 m, the best solution depends on the percentage of recycled structural steel. If this percentage is greater than 90%, then the best alternative is the composite box-girder bridge deck. However, if the percentage is lower, the cleanest alternative is the prestressed concrete box-girder deck. Therefore, the results show the importance of recycling and reusing structural steel in bridge deck designs.

Direct anterior resin composite bridge – a case report

Background: Dental hard tissue loss renders a tooth restorable or unrestorable. The treatment ranges from endodontic treatment to dental implant. Sometimes patients in need to restore their oral function and esthetics cannot afford those treatments due to a limited financial capability and time availability. Purpose: This case report presents a minimal invasive, single appointment, quick, and affordable alternative treatment to restore morphology, function, and esthetics. Case: A 40 years old male patient suffered enamel-dentin-pulp fracture on central incisor due to trauma. Eventhough the fracture involves pulp exposure, it remains vital. The tooth lacks sound tooth structure for ferrule effect. The patient wished to retain the tooth. Therefore, initial treatment plan comprised of reestablishing ferrule effect, root canal treatment, endodontic post, and porcelain crown. Nevertheless, due to financial and time constraint, patient refused the suggested treatment plan; thus, direct resin composite bridge was suggested. Case Management: Isolation is followed by calcium hydroxide capping of the exposed pulp. After application of etch and adhesive bonding to tooth 11, 21, and 22, nanohybrid resin composite was layered to fabricate the direct composite bridge, bonded to 11 and 21, with the following layering sequence: 1) palatal; 2) proximal; 3) body; 4) labial. The procedure took 1 hour to restore tooth morphology, function, and esthetics. Upon five years follow-up, the tooth remains asymptomatic. The direct resin composite bridge has been serving well. Conclusion: Direct resin composite bridges can be an affordable, quick, and minimal invasive treatment modality resulting in satisfactory esthetics, function, and longevity.

An Enhanced UHPC-Grout Shear Connection for Steel-Concrete Composite Bridges with Precast Decks

This article develops an enhanced UHPC-grout shear connection for steel-concrete composite bridges with precast decks. The primary improvement is the use of ultra-high performance concrete (UHPC) as the connection grout. To validate the constructability and the mechanical performance of the new connection, two series of experimental tests (including grouting tests and push-out tests) were conducted. Results from the grouting tests show that both the pressure grouting method and the self-levelling grouting method are applicable to inject the UHPC grout into the channel void of the connection. Results from the push-out tests indicate that the advanced properties of UHPC allow for a significant improvement of the shear resistance of the adhesive connection over traditional cementitious grouts. The ultimate shear capacity of the adhesive connection is controlled by the interface shear strength between the embossed steel and the UHPC grout, with a cohesion value of approximately 5.87 MPa. Meanwhile, the residual frictional resistance can be taken as approximately one-half of the ultimate resistance. The results of the finite-element analysis show that the trilinear model is reasonable to simulate the shear-slip laws of the embossed steel-grout interface and the rough concrete-grout interface.