Durability Of Bridge Decks Research Articles

Performance of large-diameter studs in thin ultra-high performance concrete slab

Ultra high-performance concrete (UHPC) is becoming a promising solution in steel–concrete composite bridges to improve the structural performance and durability of bridge decks. In contrast with conventional concrete, the excellent properties of UHPC allow for thinner and lighter designs with more efficient connections. In this study, the feasibility of large-diameter (30 mm) stud connection in thin UHPC slab was investigated to fully utilize the mechanical advantages of UHPC. The proposed composite structures employed large-diameter short stud (aspect ratio of 2.0) and UHPC slab as thin as 75 mm. Push-out tests were performed on 15 specimens with varying stud length, diameter and slab thickness. The use of large-diameter studs significantly increased the shear strength and ensured desirable failure mode of stud fracturing. The reduction of slab thickness from 150 to 75 mm resulted in little change to the shear strength, but splitting cracks appeared on the outer slab surface. Marginal effect on the shear strength was observed for large-diameter studs as the stud aspect ratio decreased from 4 to 2 and the cover thickness was reduced to 15 mm. The test results showed two main failure modes, including stud fracture via local crushing and stud fracture with UHPC pry-out. Finite element model was established to further study the stud-UHPC composite mechanism. These findings demonstrated the suitability of using short large-diameter stud and thin UHPC slab to reduce the self-weight and improve shear performance of composite structures.

Performance-Based Approach for Deciding Concrete Age for Healer Sealer Application on New Concrete

Healer sealer application is one of the capital schedule maintenance (CSM) activities for enhancing concrete bridge deck durability and extending the service life. A healer sealer is expected to seal the cracks and reduce the rate of chloride ion ingress. Highway agency policies and manufacturer specifications require maintaining a total of 28-day curing period (7-day wet and 21-day dry curing) before the application of a healer sealer on bridge decks with new concrete in patches and repairs. Consequently, the contractors have to wait for 28 days to apply a healer sealer. Delaying application time increases project completion time and cost of construction and mobility. This paper presents a performance-based approach for evaluating the possibility of reducing the 28-day waiting period for healer sealer application on bridge decks with new concrete. An experimental program was developed and executed to evaluate the impact of healer sealer application parameters on crack sealing ability. A healer sealer was applied at 14, 21, and 28 days of concrete age. The treated surface was ponded with 3% NaCl. The performance of the treated concrete was evaluated using the acid-soluble chloride content test. The results showed the possibility of applying a sealer before the end of the 28-day curing period stipulated in the current specifications. The performance-based approach presented in this paper can be used to identify the age of concrete for healer sealer application.

Evaluation of the properties of waterproofing membrane and their effect on the durability of bridge deck

A large quantity of concrete is used to construct any structure like bridges. Concrete is a heterogeneous material due to which there are chances of micro pores in it. Through these micro pores, the seepage of water is a common problem that deteriorates the reinforced steel present in these structures. The seepage of water reduces the strength of structure due to the attack of corrosion in the reinforced steel. To prevent such seepage and to increase the life of bridges, waterproofing of bridge deck is an important technique. This technique helps to make waterproof of precast segmental bridges. This paper present the evaluation of various properties of APP and SBS types of waterproofing membranes used in bridge deck and their affect on the durability of bridge deck. For the evaluation of different properties of waterproofing membrane CSIR-CRRI developed various test fixtures according to BD 47/99, ASTM, EN and IS standards. The different properties of waterproofing membrane which affect the durability of bridge deck are Tensile and Tear Strength, Adhesion strength, Low flexibility temperature, softening point etc. From this study, it is concluded that SBS is more effecting than APP in cold regions and vice-versa because the low flexibility of SBS is higher and the softening point of APP is higher.

Field Investigation of In-Service Performance of Concrete Bridge Decks in Pennsylvania

The results of an expert survey and field investigation of early-age bridge deck cracking in the Commonwealth of Pennsylvania are summarized in this paper. The goal was to use field data to identify factors that contribute to or reduce early-age cracking in concrete bridge decks and to assess the effect of cracks on the long-term durability of bridge decks. First, a survey of 71 employees of the Pennsylvania Department of Transportation (DOT) was conducted to collect and document their experience with early-age cracking and its relationship to long-term deck performance. Next, inspection data from 203 bridge decks were collected and analyzed to evaluate the effect of concrete mixture proportions and properties, construction methods, and rebar type on the propensity of the bridges to experience early-age deck cracking. The Pennsylvania DOT supplied inspection data for 40 older bridge decks and initial (after construction) inspection data for 163 new bridge decks. The results suggest that limiting the total cementitious materials content (e.g., to 620 lb/yd3) and the maximum compressive strength (e.g., to 5,000 pounds per square inch at 28 days) is advisable to reduce deck cracking. In addition, epoxy-coated rebar showed good corrosion resistance, even in cracked concrete.

Durability of Bridge Deck with FRP Stay-in-Place Structural Forms under Freeze-Thaw Cycles

AbstractThis study examines the effect of aggressive freeze-thaw (FT) cyclic exposure on strength and integrity of bridge decks built using glass fiber-reinforced polymer (GFRP) stay-in-place (SIP) structural forms that completely replace the bottom rebar layers. The concern has been whether entrapped moisture may cause frost-jacking of the form, negatively impacting deck integrity. Eleven scaled deck specimens were built, each using two flat GFRP plates with T-shape ribs running normal to girders. Both plates spanned the gap between girders and were spliced by overlapping, directly under the load. The study simulated the following surface treatments of the form: no treatment at all, adhesive bond to freshly cast concrete, and coarse aggregates bonded to the forms. Also, unbonded and bonded lap splices of the forms were tested. The decks were subjected to three cracking load cycles before being saturated and subjected to up to 300 FT cycles at +5 to −18°C core temperatures. Freezing was in air while thawi...

Chloride Penetration Resistance of a Ternary Blend Lightweight Concrete Bridge Deck

In 2010, the Tennessee Department of Transportation (TDOT) launched a bridge rehabilitation project to rerate all truss bridges with gusset plate connections due to the federal mandate after the Minneapolis bridge collapse in 2005. One bridge that needed to be renovated was the Hurricane Bridge in Dekalb County, Tennessee. To provide a durable bridge deck and meet the latest highway loading specifications, TDOT used a Class L ternary (sand-lightweight ternary) mix instead of their standard Class D (normal weight nonternary) bridge deck mix. While placing a section of the deck, TDOT would cast cylinders to send to the University of Tennessee for rapid chloride penetration (RCP), surface resistivity (SR), and compressive strength testing. Previous RCP and SR testing of the TDOT Class D mix found that the mix provides poor to moderate chloride ion penetration resistance. Research reported herein supports the use of the TDOT Class L ternary mix as an alternative to the TDOT Class D mix in order to increase bridge deck durability. The results of the Class L ternary mix cylinder testing show a decrease in chloride ion penetration, an increase in surface resistivity, higher compressive strengths, and a higher correlation between SR and RCP than Class D cylinders.

Experimental evaluation of GFRP bars as reinforcement for concrete bridge decks: Negative bending low cycle fatigue study

Bridge deck durability is often compromised due to corrosion of the steel reinforcement. The use of glass fiber reinforced polymer (GFRP) bars as a substitute for steel is a possible solution to this problematic condition. GFRP is an elastic brittle material with a high tensile strength, and modulus of elasticity that is approximately 20% that of steel reinforcement. Considering these material properties, meaningful data is required to demonstrate compliance with imposed design limits at all relevant limit states. Experimental evaluation of GFRP bars as structural reinforcement for highway bridge decks must recognize and duplicate the load and support conditions specific to this application. Laboratory testing should consider load magnitudes associated with AASHTO service, strength and fatigue limit states, indeterminacy of the deck in the transverse direction, two-way distribution of wheel loads, and load application and deck support conditions as affected by truck tire contact area and girder flange stiffness, respectively. In this research study 2-span continuous concrete beams doubly reinforced with GFRP bars are tested under load and support conditions designed to simulate performance of the GFRP reinforcement in a highway bridge deck environment. Monotonic, cyclic, and low cycle fatigue loading are applied to establish behavior of the experimental deck as related to an actual bridge deck load condition. Test results related to strength, deflection, and crack width are presented.

High-Performance Concrete Designed to Enhance Durability of Bridge Decks: Oklahoma Experience

AbstractBridges are a vital link to the nation’s mobility and prosperity, and those bridges with inadequacies will need to be repaired or replaced as soon as possible. High-performance concrete (HPC) could be the most economical solution. What typically distinguishes HPC from conventional concrete (CC) is the wide variety of cements, supplementary cementitious materials, aggregates, chemical admixtures, and fibers in use. The purpose of this research project was to demonstrate the use of HPC in bridge decks in Oklahoma. HPC mixtures were designed with an optimum blend of three aggregates. With less voids between aggregate particles, the HPC mixtures contained less cement paste, approximately 24% by volume. Examined more than one year after construction, crack densities were less on HPC bridge decks than CC bridge decks. HPC mixtures with fly ash exhibited the best potential durability with crack densities less than 0.1 m/m2. The addition of fibers did not have an effect on crack density.

Test Method for Appraising Future Durability of New Concrete Bridge Decks

The nondestructive test procedure for quantifying the future durability of bridge deck concrete is based on the fundamental relationship between ultrasonic pulse velocity (UPV) and the permeability of an elastic medium. An experimental study using standard concrete cylindrical specimens (ASTM C192) documented adequate sensitivity between UPV and permeability. The test procedure uses a parameter directly proportional to increase in-field concrete permeability called paste quality loss (PQL). The PQL is computed from UPV measurements on standard concrete specimens made from field concrete mixture (ASTM C31) and measurements on field concrete. Deck replacement projects on three National Highway System bridges were used as demonstration sites to implement the test procedure. The 56-day PQLs were calculated as 15%, 28%, and 9%, demonstrating a significant variability in the permeability of the three bridge decks. Field permeability tests were also conducted with Figg’s apparatus for comparison purposes. The PQL evaluation from postconstruction measurements is an effective and reliable method for testing the future durability of bridge decks.

Use of Conventional and High-Performance Steel-Fiber Reinforced Concrete for Bridge Deck Overlays

Cost-effective long-term solutions for the current problem of the deteriorated national infrastructure are critical for the future economic growth and competitiveness of the United States economy in the 21st century. One of the most important issues is the repair and retrofitting of concrete bridge decks. Deck overlays are commonly used for recovering and improving the serviceability and durability of bridge decks. This paper presents cement-based composites that offer long-term solutions to bridge deck problems: high-performance (steel) fiber reinforced concretes (HPFRCs), and improved conventional steel-fiber reinforced concretes (FRCs). Improved FRCs, and in particular revolutionary new HPFRCs, display superior strength, toughness, fatigue and impact resistance, crack control, impermeability, and durability over conventional cement composites. Thus, they are ideally suited for the construction of durable and cost-effective thin-bonded bridge deck overlays. This paper reviews successful pilot projects and presents recommendations for the design and construction of these high-performance overlay systems.