RC Bridge Deck Research Articles

Influence of Climate Change on the Probability of Chloride-Induced Corrosion Initiation for RC Bridge Decks Made of Geopolymer Concrete

Influence of Climate Change on the Probability of Chloride-Induced Corrosion Initiation for RC Bridge Decks Made of Geopolymer Concrete

Code-specified early delamination detection and quantification in a RC bridge deck: passive vs. active infrared thermography

Code-specified early delamination detection and quantification in a RC bridge deck: passive vs. active infrared thermography

Automatic Rebar Picking for Corrosion Assessment of RC Bridge Decks with Ground-Penetrating Radar Data

Automatic Rebar Picking for Corrosion Assessment of RC Bridge Decks with Ground-Penetrating Radar Data

Flexural Behavior of Prefabricated RC Bridge Deck with Different Joint Materials

This study investigated the flexural behavior of prefabricated RC bridge decks with different joint materials, normal strength concrete or UHPC (normal strength concrete for RC deck, while UHPC means ultra-high performance concrete). A total of three specimens were tested and subjected to four-point bending loads. The load–deflection curve, strain curve, load–crack width curve, and failure mode were analyzed. Numerical models with cohesive models were built and verified with test results to explore the force-transferring mechanism. The results show that UHPC effectively improved the crack strength, flexural strength, and failure mode. Compared with the joint with normal-strength concrete, the crack strength and flexural strength increased by 66.7% and 6%, respectively. The failure mode of the specimen with UHPC as joint material changed from a concentrated cracking failure of the joint to a multi-crack development failure. The behavior of the specimen with UHPC as joint material was similar to the monolithically cast specimen. In addition, the application of the current design method was evaluated and compared with test results.

Full-scale Field Test Extraction of Natural Frequency and Acceleration of Bridge using Modal Test and Operational Modal Analysis

Vibration in bridges occurred due to several factors such as structural design, environmental loadings, and loading characteristics (speed parameter, loading patterns, and configuration of axles). If this problem is prolonged for several years, this may lead to stages of failure such as structural cracking, fatigue on structural members, excessive deformation, and local stress concentration on structural connections. In response to this issue, an investigation was carried out in this study by utilising numerical modelling of Finite Element Analysis (FEA) to explore the effect of the Intermediate Diaphragm (ID) on the RC bridge deck. The FEA is then validated and confirmed from the full-scale field-test, which consists of a modal test for both frequency and mode shape comparisons, and operational modal analysis for extraction of deck acceleration. The results show that the current natural frequency of the bridge does not reach the minimum frequency requirement from the BS5400 Code of Practice, while the acceleration based on a 24-tonnes moving truck is within the allowable acceleration limit. In comparison, frequency, mode shape and acceleration between the FEA numerical analysis and field test had shown insignificant differences and minimum error between the two.

Fatigue tensile testing of glass fiber-reinforced polymer reinforcing bars

• A test method for tensile fatigue of bare GFRP bars is proposed. • Stresses of GFRP-reinforced concrete bridge decks under service loads are provided. • Results of a bare GFRP bar subjected to 5-million cycle fatigue test are provided. Glass fiber-reinforced polymer (GFRP) bars are a valid alternative to traditional steel bars for reinforcing concrete structures in specific situations. Although the elastic modulus of GFRP bars is generally 20–25% of that of steel bars, which entails for a higher cross-sectional area of GFRP than of steel bars for the same axial stiffness, they have superior durability with respect to the steel counterpart, which makes them suitable for applications in aggressive environments, such as those exposed to the chloride attack. Among these, RC bridge decks represent a typical case where GFRP bars strongly increases the structure durability, since they do not suffer for the chloride attack caused by the use of deicing agents. Bridge decks are subjected to cyclic loads that may induce fatigue issues. However, quite limited studies are available in the literature regarding the fatigue behavior of GFRP bars. In this paper, the test method for tensile fatigue provided by the European standard ISO 10406–1 is discussed and modified to account for the actual cyclic stresses applied to representative RC members subjected to fatigue, namely bridge decks. The results of a tensile test of a GFRP bar according to the modified procedure are then presented and discussed.

Automatic Corrosive Environment Detection of RC Bridge Decks from Ground-Penetrating Radar Data Based on Deep Learning

Automatic Corrosive Environment Detection of RC Bridge Decks from Ground-Penetrating Radar Data Based on Deep Learning

The examination of applicability of the long basis optical stand sensors regarding the progression of deterioration of the RC bridge deck slabs

The examination of applicability of the long basis optical stand sensors regarding the progression of deterioration of the RC bridge deck slabs

Comparative Evaluation of Crack Width for Reinforced Concrete Bridge Deck

Abstract: Cracking in reinforced concrete bridge decks is a massively concern in the India. Many concrete bridge decks, inobservant to the age of construction, have shown different levels and patterns of cracking. Not only does cracking of bridge decks weaken the bridge infrastructure, but also allows the inflow of corrosive agents into the reinforcement. In this study, the crack width evaluation of RC bridge deck of span of 5 m. and 9 m. is based on equations given by IRS Concrete Bridge Code 1997 for different cases like- the effect of depth variation, reinforcement diameter, clear cover, variation in live load moment, spacing of tension reinforcement and different no. of tension reinforcement bar to constant width for the same crosssection. This study concluded that crack width increases with increase in clear cover, variation in live load moment and spacing of tension reinforcement while it decreases with increase in reinforcement diameter, depth of the bridge deck and number of reinforced bars and percentage change evaluation of different parameter of 5m and 9m span bridge deck. Keyword: Crack Width, Cracking, Bridge Deck Slab, Crack Spacing.

Long-term strain measurements of traffic and temperature effects on an RC bridge deck slab strengthened with an R-UHPFRC layer

This paper presents the results of 28-month-long monitoring of a slab portion of the Chillon viaducts in Switzerland using strain gauges and thermocouples. This post-tensioned reinforced concrete structure was strengthened with a layer of reinforced ultrahigh-performance fibre-reinforced cementitious composite (UHPFRC). The strain gauges are used to measure stresses in the bottom layer of reinforcement bars in the slab, while thermocouples explain the behaviour of the structure due to temperature variation. The response under both traffic and thermal actions is discussed. It is demonstrated that the stress variation due to the thermal action can be as large as the response due to traffic action even in such a massive structure. Furthermore, recommendations for analysing both traffic and thermal-induced stresses are given. The commonly used simplified method for calculation of fatigue stress is shown to be highly conservative, leading to overestimation of structural action effects by a factor of four.

Probabilistic reliability framework for assessment of concrete fatigue of existing RC bridge deck slabs using data from monitoring

Assessment of existing bridge structures for inherent safety level or for lifetime extension purposes is often more challenging than designing new ones. With increasing magnitude and frequency of axle loads, reinforced concrete bridge decks are susceptible to fatigue failure for which they have not been initially designed. Fatigue verification and prediction of remaining service duration may turn out to be critical for civil infrastructure satisfying the required reliability. These structures are exposed to stochastic loading (e.g. vehicle loads, temperature loads); on the resistance side, reinforced concrete also behaves in a stochastic way. This paper presents a probabilistic reliability framework for assessment of future service duration, which includes probabilistic modelling of actions based on large monitoring data and probabilistic modelling of fatigue resistance based on test data. A case study for the steel - reinforced concrete slab of the Crêt de l'Anneau Viaduct is presented along with calibration of resistance partial safety factors for lifetime extension.

Assessment of a cantilever bridge deck slab using multi-level assessment strategy and decision support framework

A Multi-Level Assessment Strategy has previously been proposed and proved feasible for structural analysis of existing RC slabs. In this paper, the Multi-Level Assessment Strategy, which focuses on sophisticated structural analysis, was used to investigate the load-carrying capacity and structural behaviour of a composite bridge with an RC bridge deck slab subjected to a concentrated load. In addition to more sophisticated structural analysis, improved knowledge content about the structure and more advanced models for uncertainty consideration were also incorporated in a systematic way for higher levels of assessment. Furthermore, a decision support system was adopted, in which the cost for different alternatives regarding if and how the assessment should be enhanced with respect to model sophistication, knowledge content and modelling uncertainty were compared in a systematic way. The results show not only that the load-carrying capacity and the structural behaviour can be assessed with different level of detailing, but also that the cost for each level of assessment can be evaluated with a decision support system, facilitating more sustainable management of infrastructure.

Image analysis on the flexural behaviors of RC beams with artificial damage and the effects of repair

In cold and snowy regions, frost damage happened in an RC bridge deck slab leads to horizontally layered cracks, which results in the disintegration of cover concrete. Since this deterioration mode occurs inside an RC slab, it is usually difficult to detect them. It is possible that the slab performances have already decreased when the deteriorations appear on the exterior surface. As a preliminary step towards the establishment of a method for evaluating the structural performance of such a damaged RC slab, the purpose of this paper is to investigate the relationship between deteriorations and structural behaviors and to study the effect of an epoxy injection repair. For simplification, RC beams are prepared with artificial cracks that simulate deteriorations and these were made by the use of expansive agent. These beams are tested in flexure. Since the damage is volumetric, image analysis is useful to capture the two-dimensional deformations. It is shown that with different deterioration depths that is a part of the compression side of the beam or full of the height, there are differences about the deformation behaviors, the repair effects and the distributions of maximum and minimum principal strain.

An analytical study about the deformation behavior of a real scale RC bridge deck on steel girders with alkali silica reactions in real environmental conditions

An analytical study about the deformation behavior of a real scale RC bridge deck on steel girders with alkali silica reactions in real environmental conditions

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.

Determination of dominant degradation mechanisms of RC bridge deck slabs under cyclic moving loads

In this paper, fatigue behaviors of RC bridge deck slabs which fail in an unexpected but widely observed punching shear failure mode under cyclic moving loads is analyzed following a fracture mechanics based theoretical method. This method is developed focusing on the propagation and failure along the critical punching shear cracks. From analysis, some key indicators of structural fatigue performances, including the fatigue crack growth of critical punching shear crack, stress evolutions of all materials and sectional forces, moments and crack mouth opening displacements (CMODs) due to all components along the critical punching shear crack cross sections and fatigue life, are obtained. These information are then based on to identify the dominant degradation mechanisms of RC bridge deck slabs subjected to cyclic loads, which provides meaningful and reliable references for the development of an efficient and accurate numerical method.

Infrared thermography model for automated detection of delamination in RC bridge decks

The analysis of Infrared thermography (IRT) data to evaluate the condition of concrete bridge decks still relies on user interpretation of thermal images. Delaminations are commonly defined based on the pixels associated with temperatures higher than predefined threshold values that are arbitrarily selected. Such a subjective scheme can produce inconsistent results. The present study proposes a robust automated procedure for detecting and classifying delaminations in concrete bridge decks. IRT testing was conducted in-situ on full-scale bridge decks. The thermal images were enhanced and a stitching algorithm was developed using especially written codes to create a mosaicked thermogram of the entire bridge deck from individual images. Image analysis based on the k-means clustering technique was utilized to segment the mosaic and identify objective thresholds. Hence, a condition map delineating different categories of delamination was created. The proposed procedure was implemented in four full-scale bridge decks and validated via the results of other technologies obtained on the same bridges. The proposed approach resulted in effective identification of delaminated areas within the bridge decks. The findings could stimulate wider acceptance of IRT as a rapid, systematic and cost-effective evaluation technique for critical bridge deck deficiencies, allowing to focus maintenance and repair budgets on most deserving bridge decks.

Efficient damage inspection of deteriorated RC bridge deck with rain-induced elastic wave

To maintain a large number of bridges, efficient inspection methods are needed. We have developed a new and efficient method for inspecting reinforced concrete bridge decks by using acoustic emission (AE) monitoring. Notably, we use AE signals acquired during heavy rain, which have generally been considered to be noise in the past. Analysis of rain-induced AE signals reveals severe cracks deep inside a deck, which would have been difficult to recognize by conventional passive non-destructive testing. Our method is also quite efficient with measurements able to be completed in a very short period of time.

Computational Life Assessment of ASR-damaged RC Decks by Site-Inspection Data Assimilation

To estimate the remaining life of existing RC bridge decks damaged by alkali silica reaction (ASR), multi-scale numeri-cal analysis with chemo-hygral model is integrated with visual inspection data at site. First, the applicability of the poro-mechanical models for ASR expansion in the multi-scale frame are examined with the experiments of the real scale RC slabs and the model is validated to bring about fair prediction of the 3D anisotropic expansion and the fatigue life of the slabs. Second, visually inspected cracks on bottom surfaces of RC decks are converted to space-averaged strains, and the magnitude of ASR is estimated from the vertical deformation, based on which the internal pre-stress and the damage fields are re-produced by numerical predictor-corrector cycles, and the remaining life of ASR damaged RC bridge decks is fairly estimated. By conducting sensitivity analyses in terms of ASR-gel volumes and cracks, allowable error range of site inspection data is clarified to meet the requirement of asset management.

Rational Condition Assessment of RC Bridge Decks Subjected to Corrosion-Induced Delamination

AbstractPrecise evaluation of the condition of RC bridge decks, particularly for corrosion-induced delaminations, is decisive for ensuring bridge performance and safety. Although infrared thermogra...