Road Bridge Deck Research Articles

Aerodynamic interference between road vehicles and bridge deck subjected to vortex-induced vibration

An accurate assessment of the driving comfort and safety of road vehicles moving on a long-span bridge subjected to vortex-induced vibration (VIV) is essential for bridge administrators to decide whether the bridge should be closed to traffic. However, previous assessments often ignore the aerodynamic interference between the road vehicles and the bridge deck subjected to VIV. In this study, a specific wind tunnel model is developed to explore the aerodynamic interference between road vehicles and twin-box bridge deck during VIV. The vortex-induced force (VIF) and vortex-induced response (VIR) of the twin-box bridge deck and the aerodynamic forces on the vehicle were simultaneously measured. The influence of the vehicles on the VIV of the deck was investigated, and the influence of the deck vibration on the aerodynamic forces of the vehicle was also explored. The results show that the VIR and VIF of the bridge deck were generally reduced, depending on the type, position, and number of vehicles. The aerodynamic forces of vehicles could be amplified due to the deck vibration. These findings supplement the database of vehicle aerodynamic coefficients for assessing the driving comfort and safety of road vehicles moving on a long-span bridge subjected to VIV.

Influence of Graphene oxide on abrasion resistance and strength of concrete

Graphene Oxide (GO) has recently gained significant attention as a new carbon-based nanomaterial (CBN) in the civil engineering industry due to its exceptional mechanical and functional properties. It has been increasingly gaining popularity due to its superior dispersibility characteristics in aqueous solutions compared to the other graphene-based derivatives due to attached oxygen functional groups. A majority of current studies are focused on investigating the effect of GO in cement composites. However, the more useful applications of GO lie in its incorporation into concrete, as it is the most widely used construction material. Therefore, the current study determines the performance of GO-incorporated concrete in terms of strength and abrasion characteristics. Industrially produced GO was added to the concrete mixes at percentages varying from 0.02% to 0.08% by weight of cement (bwoc). A polycarboxylate-ether-based superplasticiser (PS) was used to enhance the dispersibility of GO within the mix and the workability of concrete mixtures. The Standard slump tests were performed to evaluate the workability of the mixes. Compression and indirect tensile strength tests were conducted to obtain the mechanical properties, while abrasion tests were employed to investigate the durability properties. In addition, microstructural properties were obtained using scanning electron microscope (SEM) analysis. The test results show that adding 0.08% GO bwoc in the concrete mix enhanced its compressive strength, indirect tensile strength, and abrasion resistance by 21%, 12% and 23% at 28 days compared to the control mix. At 56 days, results show 19%, 12% and 20% improvements, respectively. These findings confirmed that adding GO can enhance concrete's abrasion resistance and mechanical properties. Therefore, it demonstrates promising outcomes of utilising GO in applications such as road pavements, airport runways, industrial floorings and bridge decks where abrasion resistance and strength are key design parameters.

Retrieval of Road Surface (Bridge Deck) Temperature near 0 °C Based on Random Forest Model

Based on the road surface (bridge deck) temperature, relative humidity, air temperature, wind speed and precipitation observed at two road surface meteorological stations and two bridge deck meteorological stations, as well as subsurface temperature at different depths observed at Hefei meteorological station, the independent variables are selected to establish the relationship between these factors and road surface temperature, using random forest and stepwise regression. The performance of these two methods was compared, and the importance of each factor was analyzed. Results show that the road surface (bridge deck) temperature linearly correlates with air temperature. In the case of low air temperature conditions (air temperature ≤ 8 °C), the road surface temperature is mainly higher than air temperature observed at the same station, and the bridge deck temperature is mainly lower than air temperature. In the retrieving of road surface temperature and bridge deck temperature, the random forest algorithm has lower mean absolute error (MAE) and root mean square error (RMSE) than the stepwise regression algorithm, especially in the retrieving of road surface temperature. MAE of road surface temperature retrieved by random forest on two bridge deck stations is reduced by 0.19 °C and 0.26 °C compared with the stepwise regression, and RMSE is reduced by 0.33 °C and 0.49 °C, respectively. The bias in the retrievals can be originated from the model itself and the error in the observations. Among the factors in the random forest model, air temperature is the most important. Meanwhile, there are differences in the importance of each factor in the retrieval of road surface temperature and bridge deck temperature. The subsurface temperature is more important in retrieving road surface temperature, while humidity and wind speed are generally more important to bridge deck temperature. It should be noted that due to the limitation of the observations, this study did not consider the net radiative flux, and the influence of net radiative flux on bridge deck and road surface temperature may be different.

Characterisation of local damage in pultruded GFRP road bridge decks with random fibre mat misalignments

The extent to which random, manufacturing-induced fibre mat misalignments compromise the structural integrity of pultruded GFRP road bridge decks is not fully understood. The problem is often critical at the web-flange junctions, which frequently contain the most severe misalignments and are subjected to high moment-shear (M−V) combinations due to local tyre load effects. To that end, in the presently reported experimental study, determinate M−V combinations were applied at the junctions of a pultruded GFRP bridge deck, without artificially restraining (e.g. by clamping, which spuriously strengthens) these junctions. For any given M−V ratio, significant scatter was observed in the damage patterns and loads up to ultimate, owing to random fibre mat misalignments which have been digitally documented in a previous paper. Damage occurred mostly within the junctions, and sometimes in the adjoining flanges. Relative to misalignment-free specimens, the first fracture moments dropped by 19% and 21% for junctions containing flip and wrinkle misalignments respectively. 19% of tests showed higher tangent stiffnesses after damage, probably due to beneficial changes in load-carrying mechanism. A three-pronged approach, based on the load-response, acoustic emission and video data, enables the definition of damage indices, thereby paving the way for integrity assessment of pultruded decks under local tyre load effects.

Mechanical properties of steel fiber reinforced concrete material in construction of road bridge deck

In order to improve the application effect of steel fiber reinforced concrete (SFRC) in road bridge construction, the mechanical properties of SFRC with different fiber content were analyzed. The SFRC specimens with 0%, 0.5%, 1%, 1.5% and 2% fiber content were designed, and the mechanical properties were tested. The results showed that the compressive strength first increased and then decreased with the increase of fiber content, and the maximum compressive strength of SFRC1.5 reached 40.86 MPa, increasing by 7.19%; the increase amplitude of tensile strength of SFRC1.5 was 73.04%, which was the most obvious; the flexural strength of SFRC increased with the increase of fiber content, and the flexural strength of SFRC2 was 9.78 MPa, increasing by 94.43%. It is concluded from the experimental results of a case study that SFRC1.5 presents the optimal overall mechanical properties and is more suitable for road bridge construction.

The effect of pozzolanic mineral additives on the strength and durability properties of structural lightweight concrete

Structural lightweight concretes have the potential to be used in road pavements and bridge decks due to their properties such as sufficient wear resistance, high impermeability, superior freeze-thaw resistance and ductile behavior. However, road pavements are directly exposed to nitric acid and sulfuric acid solutions created by the exhaust gases of transportation vehicles in humid environments. Therefore, the concrete to be used in road pavements must be resistant to these acid effects. In addition, sufficient strength must be guaranteed when used as pavement material. The aim of this study is to produce lightweight concrete suitable for road pavements and other structures exposed to acid effects. For this, the effect of silica fume (SF) and fly ash (FA) on acid resistance and strength development of lightweight concrete with perlite aggregates was investigated. Five different lightweight concrete mixtures were produced by substituting 0%, 5%SF, 10% SF, 10%FA, 20% FA instead of cement by weight. Natural perlite rock has been used as an aggregate source in order to provide high strength and lightness. The cylindrical samples produced were kept in lime saturated water cure for 120 days and their compressive strength was measured on the 28th, 56th, 90th and 120th days. In addition, in order to monitor the acid resistance, the strength changes of the samples exposed to 5% sulfuric acid and 5% nitric acid solution after 28 days of standard curing were followed until the 120th day. Results show that, SF and FA additives increase the compressive strength especially at older ages. In case of 10% SF, the 120-day strength value increased by 18.6% and reached 34.5 MPa. Also, lightweight perlite concrete is highly resistant to nitric acid and sulfuric acid effects. In the case of 92 days of nitric acid and sulfuric acid exposure, the strength losses are only 5.2% and 13.4%, respectively. In order to fully benefit from SF and FA, concretes must be adequately cured before acid attack. It has been concluded that it is possible to produce high-strength and acid-resistant lightweight concretes suitable for road pavements and many other structural elements by using natural perlite aggregate.

輪走行作用を受ける道路橋 RC 床版の疲労損傷過程に関する実験的研究

輪走行作用を受ける道路橋 RC 床版の疲労損傷過程に関する実験的研究

Fatigue Lifetime Prediction of Newly Constructed RC Road Bridge Decks

Fatigue Lifetime Prediction of Newly Constructed RC Road Bridge Decks

Development and application of a highly durable precast prestressed concrete slab deck using fly ash concrete

In the Hokuriku district of Japan, alkali-silica reaction (ASR), salt damage, frost damage, and other problems of premature deterioration have caused severe degradation in many road bridge decks, and the use of fly ash concrete as a rational suppression measure is being standardised. This work outlines the actual situation of complex degradation by ASR and salt damage of road bridge reinforced concrete slab in the Hokuriku district and introduces the history of the research and development of high-durability precast prestressed concrete (PCa PC) slab deck using fly ash concrete and examples of social implementation in this region. Moreover, full-size PCa PC slab specimens with and without fly ash content are constructed and subjected to both bending and pushing shear loading tests to investigate the differences in their bending and punching shear resistance. Numerical models are then developed using finite element method to evaluate the experimental results. Analyses elicited good agreement between simulations and experimental data and validated the numerical models. Based on the obtained results, this study clarified the mechanical properties of PCa PC slab using fly ash concrete, and then its practical use in the renewal project of highway was discussed.

Analytical study on damage detection method using displacement influence lines of road bridge slab

Structural health monitoring has garnered attention as a method to quantitatively evaluate damage to road bridges, and various dynamic and static damage detection methods have been proposed recently. However, few damage detection methods focus on the displacement shapes of road bridge decks. In this study, a damage detection approach is proposed using Displacement-Based Index (DBI) and Grey Relational Coefficient (GRC), in which displacement influence lines of deck slabs are used as inputs in the evaluation procedures. Parametric studies were performed by changing the damaged positions and boundary conditions of a full-scale bridge model to examine their possible effects on the performance of the proposed method. The results indicated that either approach could properly detect damage in the simulation model. In addition, because the proposed method was insensitive to damage away from the measurement position, it was clarified that damage detection could be performed accurately by installing multiple displacement meters at appropriate intervals.

Non-destructive diagnostics of steel-reinforced concrete structures: detecting and locating reinforcement

The paper describes the possibilities of non-destructive determination of the location and depth of reinforcement in concrete structures using electromagnetic cover meters. It is currently one of the most popular methods for determining the location, cover depth and diameter of reinforcement. However, there are not many sources that would give a detailed description of specific measurement results. This paper describes the use of the Profometer PM-630 cover meter for in-situ measurement of a steel-reinforced-concrete road bridge deck. The paper details the results of measurements of cover depth, bends in reinforcement, and discusses the strong and weak points of the method.

Influence of Overheating Phenomenon on Bitumen and Asphalt Mixture Properties

In the course of manufacturing, transport and installation, road bitumens and asphalt mixtures can be exposed to the impact of elevated process temperatures exceeding 240 °C. This mainly applies to the mixtures used for road pavements and bridge deck insulation during adverse weather conditions. The heating process should not change the basic and rheological properties of binders and the asphalt mixtures that to a degree cause the degradation of asphalt pavement durability. The work involved analyzing the properties of non-modified bitumens and SBS polymer modified bitumens, heated at temperatures of 200 °C, 250 °C and 300 °C for 1 h. Next, the asphalt mixtures were heated in the same temperatures. Based on the developed Overheating Degradation Index (ODI) it was demonstrated that polymer-modified bitumens were characterized by higher overheating sensitivity A(ODI) than non-modified bitumens, which was confirmed by mixture test results. Overheating limit temperatures T(ODI) were determined, which in the case of polymer-modified bitumens are up to 20 °C lower than for non-modified bitumens. When the temperature increases above T(ODI), loss of viscoelastic properties occurs in the material which causes, among other effects, a loss of resistance to fatigue cracking.

Quantitative Deterioration Assessment of Road Bridge Decks Based on Site Inspected Cracks under Stagnant Water

Quantitative Deterioration Assessment of Road Bridge Decks Based on Site Inspected Cracks under Stagnant Water

ASSESSING THE CONDITION OF BURIED PIPE USING GROUND PENETRATING RADAR (GPR)

Abstract. The invention of Ground Penetrating Radar (GPR) technology has facilitated the possibility of detecting buried utilities and has been used primarily in civil engineering for detecting structural defects, such as voids and cavities in road pavements, slabs and bridge decks, but has not been used to assess the condition of buried pipes. Pipe deterioration can be defined as pipes where, for example, cracking, differential deflection, missing bricks, collapses, holes, fractures and corrosion exists. Assessing the deterioration of underground pipes is important for service efficiency and asset management. This paper describes a research project that focused on the use of GPR for assessing the condition of buried pipes. The research involved the construction of a suitable GPR test facility in the laboratory to conduct controlled testing in a dry sand. Plastic pipes were chosen for the experiments. A series of laboratory experiments were conducted to determine the validity and effectiveness of standard commercially available GPR technology in assessing the condition of buried utilities with common types of damage. Several types of damage to the plastic pipe were investigated with respect to different GPR antenna frequencies. The GPR surveys were carried out in order to obtain signal signatures from damaged and undamaged pipes buried at 0.5 m depth. These surveys were organised on a grid pattern across the surface of the sand in the test facility. The results presented in this paper show that GPR can identify certain types of damage associated with a buried pipe under these controlled laboratory conditions.

Quantitative Deterioration Assessment of Road Bridge Decks Based on Site Inspected Cracks

By integrating a multi-scale simulation with the pseudo-cracking method, the remaining fatigue life of in-service reinforced concrete (RC) bridge decks can be estimated based upon their site-inspected crack patterns. But, it still takes time for computation. In order to achieve a quick deterioration-magnitude assessment of RC decks based upon their crack patterns, two evaluation methods are proposed. A predictive correlation between the remaining fatigue life and the cracks density (both cracks length and width) is presented as a fast judgment. For fair-detailed judgment, an artificial neural network (ANN) model is also introduced which is the basis of the machine learning. Both assessment methods are built commonly by thousands of artificial random crack patterns to cover all possible ranges since the variety of the real crack patterns on site is more or less limited. The built ANN performances are examined by k-fold cross-validation besides checking the prediction accuracy of real crack patterns of bridge RC decks. Finally, the hazard map of the deck’s bottom surface is introduced to indicate the location of higher risk cracking, which derives from the estimated weight of individual neuron in the built artificial neural network.

Remaining fatigue life assessment of in-service road bridge decks based upon artificial neural networks

By using a multi-scale simulation together with the pseudo-cracking method, the remaining fatigue life of real RC bridge decks is estimated based upon their site-inspected surface crack patterns of a wide variety, and it is confirmed that the crack location and its orientation are primary factors on the remaining life together with crack width. For quick diagnosis for the remaining fatigue life at the site, an artificial neural network (ANN) to correlate the fatigue life with observed cracks is built up based upon large numbers of assessed fatigue life related to wide range of crack patterns and their widths. Artificially created crack patterns associated with the firm coupling of shear and flexure are also included in training dataset to cope with indeterminate crack events which may arise in future and to assure a robust and reliable artificial neural network model. It is recognized by conducting the cross-validations that the training data-set for ANN shall include crack patterns rooted in mechanically possible modes of failure. Otherwise, the risk of wrong assessment due to overlearning will arise.

Interpretation of sensor data from in situ tests on a transversely bonded fibre-reinforced polymer road bridge

The Frampton Cotterell fibre-reinforced polymer road bridge deck comprises pultruded glass-fibre-reinforced polymer units which are laid longitudinally and are adhesively bonded transversely, in contrast to previous glass-fibre-reinforced polymer deck bridges where the pultruded units were laid transversely. This novel layout dictates that transverse distribution of live loading occurs only through the deck’s flanges and entails possible transverse tension which should be controlled to avoid cracks through the bonded deck–deck joints. This article assesses these structural actions by interpreting strains and deflections recorded during lorry testing of the bridge. Transverse distribution is evaluated by comparing transverse profiles of recorded longitudinal strains and of predicted longitudinal moments, with the conclusions qualitatively reinforced using a deflected surface based on the test recordings. Evidence of the deck acting as a continuum free of propagating joint cracks comes from the fact that the strains recorded during complementary lorry runs along the bridge satisfy the superposition principle and that the recorded strain influence lines replicate an idiosyncratic feature of the moment influence line without redistribution effects. That feature was then exploited to inform the strategy for a braking test which produced valuable vibration data for the bridge. Test data integrity is corroborated by cross checking deflections recorded from different types of sensors. It is concluded that since longitudinal placement of pultruded decks enhances the versatility of fibre-reinforced polymer bridges, this sensor layout and data interpretation process may form part of a wider strategy for health monitoring of such bridges.

Damage Assessment of Road Bridges Subjected to the 2011 Tohoku Pacific Earthquake Tsunami

The authors assessed the tsunami damage to a girder-type road bridge, focusing on a washed-away deck that failed during the 2011 Tohoku Pacific earthquake tsunami. The inundation depth, ratio of inundation depth to girder elevation, and flow velocity were used as the three indices of the tsunami wave load acting on a road bridge deck. A gently shaped tsunami waveform was selected at a wave-front with a water surface level increase rate of less than 2.0 m/min. The damage ratio was computed for the above three indices, as defined by the number of washed-away bridges divided by the total number of bridges exposed to the tsunami. Based on statistical analysis for the damage ratio data, damage functions using the three indices were proposed. In addition, the spatial distribution of physical wash-away damage to road bridges by the anticipated Nankai Trough earthquake tsunami was shown by applying the derived damage functions.

Study on the curvature of the road bridge deck under live load action

Study on the curvature of the road bridge deck under live load action

Proposal of Domestic Road Bridge Deck Deterioration Models and Forecast of Replacement Demand

Proposal of Domestic Road Bridge Deck Deterioration Models and Forecast of Replacement Demand