Bridge decks in the USA are designed according to the AASHTO LRFD Bridge Design Specifications using various refined and approximate methods. The traditional strip method as well as the empirical method have been applied to reinforced concrete decks. However, with the development of new and innovative construction materials, including nonmetallic rebars and tendons, FRP composites, fiber reinforced concrete, full depth precast decks, as well as other types of materials, there is a need to develop or adjust design philosophies and approaches to capture the enhanced performance of the recent innovations in construction materials for bridge decks.
This session will also be an opportunity to combine the efforts among ACI and ASCE researchers and practitioners in addressing various topics related to new and innovative designs/materials of concrete bridges.
(1) Create awareness on topics related to design of bridge decks;
(2) Identify advanced and innovative materials used in the construction of concrete bridge decks;
(3) Compare deck design procedures in different states;
(4) Discuss recommendations for deck design procedure to avoid current problems.
This session has been AIA/ICC approved for 2 CEU/PDH credits.
Implementation of Fiber Reinforced High-Performance Concrete (FR-HPC) for Bridge Decks in New Jersey
Presented By: Adi Abu-Obeida
Affiliation: Infrastructure Monitoring and Evaluation (RIME) Gr
Description: High-Performance Concrete (HPC) is categorized as concrete with optimal strength, shrinkage, and durability properties. However, HPC in bridge decks is still prone to transverse cracking especially with vibrations due to traffic in adjacent lanes or construction loads. To mitigate concrete cracking, the addition of macro fibers is investigated with HPC mixes. The effects of adding various types of fibers coupled with aggregate blending on HPC were experimentally investigated in the laboratory in terms of strength and shrinkage properties as well as cracking potential which is evaluated using the ring test in accordance with the AASHTO-T334. Results show that the addition of steel hooked or polypropylene fibers reduced the cracking area (i.e., crack width multiplied by crack length) at 56 days by 26.3% and 23.2%, respectively. Based on the laboratory results, the team implemented FR-HPC and typical HPC, alternatively, in reconstructed bridge decks in New Jersey. Three crack map surveys were performed prior to opening the bridge to traffic over a period of 290 days. Results show that FR-HPC reduced the mean crack width by 28.6%, and the cracking area by 33.3%. This study illustrated that FR-HPC is effective in improving the cracking performance of reconstructed bridge decks casted while traffic in the adjacent lane is uninterrupted.
Accumulated Fatigue Damage in Concrete Bridge Decks
Presented By: Andrzej Nowak
Affiliation: Auburn University
Description: The objective of the presented research is to review the fatigue damage and service life consumption for concrete bridge decks by overweight vehicles. The analysis is based on the WIM traffic data and issued permit database to determine the total consumption of bridges, caused non-permit, permit, and illegal vehicles. Deterioration of concrete decks will be studied using material models, from early age concrete to cracked slab. Damage accumulation model will be developed to assess life consumption. The results of the study will have applications in budgeting, maintenance, and planning enforcement on highways.
Performance of 45-Year Old Damaged Double-Tee Girder Bridges
Presented By: Mostafa Tazarv
Affiliation: South Dakota State University
Description: Precast prestressed double-tee girder bridges have been frequently used in South Dakota and the neighboring states especially on local roads. Double-tee bridges are cost-effective and are easy to construct and install. Nevertheless, many of these bridges are deteriorating due to insufficient detailing and environmental conditions. Two 45-year-old double-tee girders, one 30-ft (9.14-m) and another 50-ft (15.24-m) long, were extracted from a bridge in Rapid City, SD, and were tested to failure at the Lohr Structures Laboratory at South Dakota State University. The salvaged girders, as received, had extensive damage such as exposure of tendons, loss of stem concrete, and flange concrete spalling. The presentation will highlight the findings of the experimental study and discuss a methodology proposed to load rate damaged double-tee girder bridges.
Life Cycle Cost Analysis of Alternative RC Bridge Decks
Presented By: Christopher Eamon
Affiliation: Wayne State University
Description: A life cycle cost analysis was conducted on various alternative types of bridge deck construction, including variations of traditional and state-of-the-art reinforcement and concrete material technologies. Uncertainties in primary agency and user costs over the deck lifetime, in order to maintain a serviceable structure, were considered. Results are presented in terms of the cumulative yearly probability of one alternative being less than another.
Long-Term Performance of a Solid Slab Bridge Subjected to Various Corrosive Environments
Presented By: Yail Jimmy Kim
Affiliation: University of Colorado Denver
Description: This study presents the long-term performance of a sold slab bridge subjected to various corrosive environments. Element-level simulations are conducted by agent-based modeling in tandem with percolation theory, while structure-level investigations focus on capacity degradation resulting from corrosion damage. Performance-based assessments are carried out to understand the detrimental consequences of corrosion damage for 100 years.
Performance of Fiber-Reinforced Flowable Concrete used in Bridge Rehabilitation
Presented By: Kamal Khayat
Affiliation: Missouri S&T
Description: This paper presents the results of a field implementation involving the use of highly flowable fiber-reinforced concrete (FRC) for the re-construction of a new deck slab of a bridge in Missouri. The-two span girders type bridge consists of four girders with span lengths measuring about 126 ft and 115 ft in length. The width of the bridge is 30 ft. A FR-SWC made with 0.5% micro-macro steel fibers and 5% CaO-based expansive agent that can develop high tensile strength, low shrinkage, and high resistance to cracking was selected for the re-decking work given the anticipated high tensile stresses in the bridge deck at the intermediate bent and the relatively high concentration of steel reinforcement necessitating the use of a highly flowable fibrous mixture. The FRC was easily pumped and finished and had slump values of 6 to 10 in. and air volume of 4.4% to 5.8%. The 56-day compressive and flexural strengths were 7,770 psi and 860 psi, respectively. The average shrinkage values determined at 56 and 260 days of age were limited to 185 and 320 micro-strains, respectively. The presentation will report on the in-situ performance of the concrete and performance of the proposed FRC.