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This study comprehensively evaluates the field applicability of hydraulic modified sulfur (HMS) as a concrete additive. We assessed the microstructural characteristics, mechanical properties, and durability performance of HMS at various replacement ratios in a laboratory setting. In addition, a field study was conducted by removing an existing conventional concrete pavement measuring (6000 × 12,000 × 70 mm, W × L × T) and overlaying it with HMS concrete. The experimental results revealed that HMS enhanced the mechanical and durability performance when used as a cement replacement at rates below 9%. These results satisfied the quality control standards and performance criteria specified in the Korean standard specification for cement-concrete pavements. The comparative analysis revealed that HMS concrete outperformed conventional concrete mixtures by 62.6% in sulfuric acid penetration depth, 14.8% in compressive strength retention after sulfuric acid immersion, and 53.1% in chloride-ion penetration resistance. Furthermore, no anomalies were detected during the 3-month follow-up period. [ABSTRACT FROM AUTHOR]

Concrete infrastructure is vulnerable to damage such as spalling. Spalling leads to chloride penetration, which causes internal corrosion, weakens structural stability and durability, and increases the likelihood of additional cracks or damage, consequently necessitating repair. Existing repair methods do not consider the factors that affect damage in the repaired areas, so additional damage can occur, making monitoring necessary to identify these factors. Nevertheless, existing studies have not adequately addressed the monitoring of internal conditions within concrete, making it difficult to manage such damage effectively. Accordingly, in this study, a monitoring system was developed using building information modeling (BIM) and the Internet of Things (IoT) to better identify internal changes in concrete pavements. Employing embedded sensors to measure temperature, humidity, and stress within the concrete, our system uses Dynamo scripts for real-time data visualization within BIM. Validated against the ASTM D8292 standard, this system captures and analyzes environmental impacts on concrete. This integration facilitates the detection of internal changes, allowing for the real-time visualization of these impacts. This study can help establish repair plans by identifying factors affecting concrete, contributing to preventive maintenance, potentially reducing maintenance costs, and enhancing the sustainability of concrete infrastructures. [ABSTRACT FROM AUTHOR]

This paper presents the parametric analysis of a combined system of a low-volume concrete pavement, base layer and reinforced expansive soil, subjected to the stresses due to wheel loading and swelling of the soil. A soil-structure Interaction model is considered for the analysis, in which the pavement and the reinforcement are idealized as a finite beam, with plane-strain conditions, whereas a base layer and the expansive soil are modelled as Winkler Springs of different stiffnesses. During the analysis, it was taken into account that the geosynthetic reinforcement, which could be in the form of a geogrid, geocell, or a combination of both, possesses bending stiffness and is placed at the interface between the base layer and the expansive subgrade. The reinforcement layer is subjected to stresses due to wheel load, self-weight of pavement slab and surcharge load of the base layer at the top and the swelling pressure from the subgrade at its bottom. The governing differential equations for the flexural response of the model are derived and a closed-form solution is presented in a non-dimensional form. The outcomes of the parametric analysis highlight that the flexural response of the pavement is predominantly affected by the relative stiffness of the base layer and the expansive subgrade. In contrast, the relative flexural rigidity of the upper and lower beams has a comparatively minor impact on the model's response. Additionally, parameters like the depth of placement of the lower beam, unit weight of the upper soil layer, and the self-weight of the upper beam also contribute to influencing the response of the pavement model. The study suggests that, while designing for the concrete pavement, opting for an increase in the modulus of subgrade of expansive soil may be a preferable choice over reinforcing the foundation of the pavement. [ABSTRACT FROM AUTHOR]

Improving concrete pavement structure is a primary objective utilized to improve road pavement performance. The effect of crumb rubber and steel fiber is to protect and strengthen the strength of reinforced pavement concrete. In this study, experimental work was conducted utilizing a concrete model to examine reaction and resistance to the effect of carloads. The experimental laboratory program was divided into four groups: standard concrete and concrete with crumb rubber, SFRC, and combined crumb rubber and SFRC. the results observed that the addition of 10 to 20% crumb rubber and 40% SFRC to concrete with an fc of 30 MPa significantly improves the concrete’s behavior under the same conditions. Additionally, the crumb rubber and SFRC shear strength enhanced in comparison to concrete characteristics.

This study focuses on the actual project of rural road ‘concrete to asphalt’ pavement renovation, deeply integrating the design concept of full structure regeneration and the innovation of in-situ regeneration technology for old cement pavement. Through the life cycle assessment method, an environmental impact quantification assessment model is used. Based on the analysis of the environmental benefits of traditional pavement renovation technology (using multi-hammer crushed stone and hot mix asphalt production technology), the environmental advantages of the full-structure regeneration technology scheme are outlined, including the recycling of recycled asphalt pavement materials, application of emulsified asphalt plant mixing cold regeneration technology, and implementation of resonance crushed stone on-site regeneration technology. At the same time, sensitivity analysis methods are used to deeply analyze the sensitivity of changes in parameters such as surface and base thickness, transportation distance, and environmental factors to the overall environmental impact. The research results indicate that the optimization plan can achieve a 57.97 % reduction in total energy consumption and a 71.45 % reduction in total carbon emissions. Additionally, the recycling and utilization of RAP materials significantly reduce the demand for new mineral materials and asphalt. For a 1-kilometer road surface, mineral materials save up to 82.39 % and asphalt saves up to 27.11 %. The energy consumption and carbon emissions generated during the raw material production stage in both schemes contribute the most to the environmental impact of road construction. The analysis found that the environmental benefits of the optimization plan mainly come from the recycling of the old cement concrete pavement as the base layer after resonance crushing, as well as the use of emulsified asphalt mixture cold recycling instead of the lower layer of hot mix asphalt concrete, achieving full-scale recycling of the pavement renovation. The relevant findings provide a data foundation or the improvement and upgrading of energy-saving and emission reduction technologies in road surface renovation and offer valuable insights for future research on sustainable road surface renovation strategies.

In seasonally frozen regions, concrete pavement is exposed to cycles of freeze-thaw and erosion from de-icing salt, which can lead to unfavorable service conditions and vulnerability to damage. This paper examines the compressive strength, flexural-tensile strength, abrasion resistance, permeability, and spacing factor of concrete, taking into account the impact of various curing conditions, de-icing salt solutions, and mass fractions on the concrete's freeze-thaw resistance. Two test methods, the single-face method and the fast-freezing method, were used to comparatively analyze the freeze-thaw resistance of concrete. The analysis was based on the surface scaling, water absorption rate, mass loss rate, relative dynamic elastic modulus, and relative durability index. The results indicate that the presence of salt solution significantly worsened the degree of concrete damage caused by freeze-thaw cycles. The use of freeze-thaw media, specifically sodium chloride ( N a C l ), calcium chloride ( C a C l 2 ), and potassium acetate ( K A c ) at mass fractions of 5%, 4.74%, and 5%, respectively, had the greatest impact on the surface scaling of concrete. However, their effect on the water absorption rate was inconsistent. When the freeze-thaw medium was water, the concrete's relative dynamic elastic modulus and relative durability index were 9.6% and 75.3% higher, respectively, for concrete cured in 20 °C—95% RH conditions compared to those cured in 0 °C—50% RH conditions. We propose a comprehensive relative durability index ( D F w ) by combining the results of two methods of freeze-thaw tests. The D F w of concrete cured in 0 °C—50% RH conditions was 83.8% lower than that of concrete cured in 20 °C—95% RH conditions when exposed to a freeze-thaw medium of 5% mass fraction N a C l solution. To evaluate the salt freeze-thaw resistance of concrete pavement, it is recommended to use surface scaling and D F w together. [ABSTRACT FROM AUTHOR]

Our aim is to analyze the function of reinforcement elements (dowel bars) in cement concrete pavement to highlight the influence of these elements on the service life of the pavement as a whole and to find possible alternatives to existing products that are freely available on the Czech market. That is, how these elements in the form of dowel bars should work properly so that the function meets the design assumptions of a rigid pavement. We describe the procedure for inserting dowel bars during paving, which is directly related to the possibilities of using different dowel bars. Finally, we summarize the possibilities of using alternative materials, shapes, or sizes of dowel bars and the possibilities of their use in the Czech Republic. [ABSTRACT FROM AUTHOR]

This study investigates the feasibility and effectiveness of employing waste ceramic (WC) in rigid pavement as a replacement for fine aggregate. WC was integrated into concrete; untreated and treated with a silane compound, where 30 wt.% and 50 wt.% sand was replaced with WC. The workability, compressive strength, water absorption, skid resistance, microstructural analysis, and surface chemistry of mixtures were evaluated. The results illustrated the positive impact of using treated WC on the water absorption of mixtures, where a maximum reduction of 19% was achieved in the mixture with 50% treated WC. Moreover, concrete with 30% treated WC attained a higher compressive strength of 43 MPa than its untreated counterpart, which achieved 29 MPa, when tested at 28 days. The integration of treated and untreated WC in concrete pavement reduced its skid resistance due to the presence of glaze in the untreated mixture and silane in the treated mixture. The morphological and surface chemistry analyses confirmed the development of C–S–H, CaCO3, and SiO2 in high contents in concrete with silane-treated WC. Also, a strong bonded interfacial transition zone was noticed in concrete with silane-treated WC, unlike concrete with untreated WC, which had a poor interfacial transition zone. [ABSTRACT FROM AUTHOR]

Concrete pavement performance models are evaluated, calibrated, and validated using field data from databases like the Long-Term Pavement Program. Conceptually, performance model predictions should match field data considering a reliability of 50%; that is, there is a 50% probability that the predictions of a certain distress indicator are higher or lower than the field data. However, modern pavements are designed for higher levels of reliability (usually 90% to 95%). Local performance model evaluation for higher levels of reliability requires a high amount of field data that traditional databases lack. Pavement management system (PMS) databases can be a useful resource for high reliability model analysis because of the large amount of data collected locally and regularly. However, when selecting and filtering field databases (of any source), the effect of censored performance data due to rehabilitation, removal from service, or modification of pavement sections is usually ignored. This paper proposes an approach for the use of PMS databases accounting for censored performance data to evaluate the accuracy of performance models' high reliability predictions. The approach is exemplified using a PMS transverse joint faulting database. Results show that by addressing the "survival issue," i.e., accounting for the censored performance data, the resulting PMS-based reliability model improves the faulting model accuracy in matching the field data for high reliability levels. [ABSTRACT FROM AUTHOR]

This paper presents research about a mixture design method of pavement concrete coblending rubber and fiber into ordinary concrete. Mechanical-based tests regarding the compressive strength, elastic modulus, splitting tensile strength, flexural strength, and four-point bending stiffness were conducted to evaluate the flexural toughness of concrete, and a slab-based three-point bending test was designed to evaluate the bending toughness improvement of the road pavement concrete slab. The results indicated that with the increase in single rubber content, the compressive strength and elastic modulus of concrete decreased continuously. The rubber concrete specimen remained relatively complete in appearance during destruction, showing the satisfied ductile failure characteristics to pavement usage with the optimal rubber content of 10%. After adding basalt fiber (BF) or polypropylene fiber (PPF), with the increase of fiber content, the bending stiffness of concrete decreased, the corresponding deflection of peak load increased continuously, and the bending deformation capacity of concrete could be significantly enhanced. Compared with the reference group, when the rubber content is 10%, and basalt fiber content is 0.5%–2%, the equivalent initial bending strength of fiber-reinforced rubber concrete is increased by 105.4%–164.4%. In general, BF is better than PPF in improving the toughness of rubber concrete, and the optimal dosage of BF is 1% of concrete volume in this test. When loaded to the limit load, the deflection of the basalt fiber–reinforced rubber concrete slab in the middle of the bottom span was about four times higher than that of the benchmark concrete slab, the bending deformation capacity and toughness of the basalt fiber–reinforced rubber cement concrete slab have been greatly improved. From the test results, the mixture design method of flexible pavement cement concrete based on rubber and fiber coblending was proposed, which contributes to the development of flexible materials for concrete pavement. [ABSTRACT FROM AUTHOR]

Our aim is to analyze the function of reinforcement elements (dowel bars) in cement concrete pavement to highlight the influence of these elements on the service life of the pavement as a whole and to find possible alternatives to existing products that are freely available on the Czech market. That is, how these elements in the form of dowel bars should work properly so that the function meets the design assumptions of a rigid pavement. We describe the procedure for inserting dowel bars during paving, which is directly related to the possibilities of using different dowel bars. Finally, we summarize the possibilities of using alternative materials, shapes, or sizes of dowel bars and the possibilities of their use in the Czech Republic.

This study presents a machine learning model for predicting representative surface distresses (crack, durability, patching, joint spall) in concrete pavements, focusing on South Korean examples. It thoroughly analyzes specific distress types using time series data to understand their development over time, aiming to surpass traditional regression methods in forecasting pavement conditions. The research fills a gap by applying machine learning algorithms to detailed long-term data, enhancing the accuracy of distress progression predictions, which is crucial for efficient pavement management. A notable aspect of this study is the use of particle filtering, recognized for its effective resampling in analyzing time series data. To validate predictions, we compared the results from particle filtering with those from traditional regression models, long short-term memory (LSTM) networks, and Deep Neural Networks (DNNs). The accuracy varied significantly, with differences ranging from 3.32% to 23.64%, indicating particle filtering's suitability for time-series-based pavement condition predictions. These findings are especially relevant in the context of current image-based machine learning and AI research in pavement distress detection and prediction. This research offers a comprehensive reference that is especially valuable due to the lack of studies using long-term usage data, thereby making a significant contribution to pavement management research and practice. [ABSTRACT FROM AUTHOR]

Concrete pavements are nowadays winning increasing attention although their use is still limited by the high stiffness or low flexibility of concrete. In addition, worn tires cause environmental problems and also have an inherent ability to absorb energy. Therefore, it is necessary to improve concrete flexibility and energy absorption capacity by adding recycled materials such as crumb rubber. For this study, impact resistance and damping coefficients were investigated as the parameters affecting the energy absorption capacity of pavement concrete as well as the compressive, flexural, modulus of elasticity, and density of rubberized concrete. Crumb rubber 0–5 mm in diameter was replaced in concrete mixes for fine aggregate at volume ratios of 0%–60% (about 25% of total aggregate volume). The numerical models were used for validating laboratory results of damping tests, showing a good agreement between laboratory and numerical model frequencies. Moreover, the influences of geometrical property, as well as crumb rubber content, on the first frequency parameter of the samples were scrutinized by employing the finite-element model. Based on the results obtained, the replacement of 60% crumb rubber led to an increase of about 75% in impact resistance required for the first crack to appear and an increase of about 170% required for the specimen to fail. The damping coefficient of the concrete containing 60% crumb rubber also increased from 2.35% to 4.19%, indicating the significantly enhanced energy absorption capacity of the concrete containing crumb rubber. However, the specimens exhibited reductions of about 32%, 36%, 43%, and 21% in compressive strength, flexural strength, modulus of elasticity, and density of concrete, respectively, as a result of crumb rubber addition. [ABSTRACT FROM AUTHOR]

Carbon fiber heating technology has been widely used in pavement surfaces in practical engineering projects as an environmentally friendly, efficient, and safe ice melting technique. However, the current design of carbon fiber-heated pavement focuses primarily on the ice melting effect while neglecting the crucial mechanical performance evaluation. Therefore, this study aims to investigate the temperature and thermal strain distributions of concrete pavement through model tests and develop a corresponding three-dimensional numerical model to analyze the temperature stress field distribution of carbon fiber-heated pavement. The accuracy of the numerical model is verified by comparing the model test results with the numerical analysis results. The numerical model test results indicate that the maximum compressive stress near the carbon fiber wire is 4 MPa, while the maximum tensile stress between the two carbon fiber wires is 1 MPa. According to the design standard for highway cement concrete pavement, the temperature stress induced by temperature change is significantly lower than the design value of the material's inherent strength. In addition, a linear relationship between the depth and temperature gradient affecting temperature stress is observed after establishing a correlation between the temperature gradient and temperature stress. The findings of this study can provide valuable insight into the design of carbon fiber-heated concrete pavements. [ABSTRACT FROM AUTHOR]

Traditional spalling repair on concrete pavement roads is labor-intensive. It involves traffic blockages and the manual calculation of repair areas, leading to time-consuming processes with potential discrepancies. This study used a line scan camera to photograph road surface conditions to analyze spalling without causing traffic blockage in an indoor setting. By using deep learning algorithms, specifically a region-based convolutional neural network (R-CNN) in the form of the Mask R-CNN algorithm, the system detects spalling and calculates its area. The program processes data based on the Federal Highway Administration (FHWA) spalling repair standards. Accuracy was assessed using root mean square error (RMSE) and Pearson correlation coefficient (PCC) via comparisons with actual field calculations. The RMSE values were 0.0137 and 0.0167 for the minimum and maximum repair areas, respectively, showing high accuracy. The PCC values were 0.987 and 0.992, indicating a strong correlation between the actual and calculated repair areas, confirming the high calculation accuracy of the method. [ABSTRACT FROM AUTHOR]

Detection of the tie bars in concrete pavement has been a challenging task. To address the purpose, ground penetrating radar (GPR) was used to acquire a large amount of image data along the longitudinal construction joints of plain concrete pavement in the field. The GPR image data was filtered to construct the dataset, containing 2185 tie bar reflected waves in 670 GPR images. Then, the YOLO series models, as the deep learning algorithms applied in inspecting the tie bars from GPR images, were well trained with the GPR training and validation sets. The comprehensive detection accuracy of the YOLOv4 model outperforms the YOLOv3, YOLOv3-tiny, and YOLOv4-tiny models in the test set. The mAP@0.5 value of the YOLOv4 model can reach 99.74%. All the signatures of tie bars in the testing GPR images, no matter whether they are incomplete, compressed, blurry with missing signal, or strong background noise, can be correctly and completely anchored using the bounding box based on the YOLOv4 model. Meanwhile, the detection speed of the YOLOv4 model for GPR data video is 50.8 frames per second. Therefore, the YOLOv4 model is reliable for automatically detecting the tie bars from GPR data in real-time. [ABSTRACT FROM AUTHOR]

Structural fibers contribute to the overall performance of concrete pavements by mitigating various distresses. To understand the influence of structural fibers on the pavement structural responses and distresses, the Minnesota Department of Transportation (MnDOT) constructed two ultra-thin (3 and 4 in. thick) and three thin (5 and 6 in. thick) fiber reinforced concrete cells along with one plan concrete control test cell at the Minnesota Road Research (MnROAD) facility in 2017. These test cells have 6 ft x 6 ft concrete slabs and were constructed on the granular base layer. While the structural designs of these cells were intended for roads with low to moderate traffic volume, the cells were subjected to accelerated loading to complete the study in a short period of time. This paper summarizes the design and construction of the six test cells and provides a comprehensive discussion on the joint performance behavior and transverse joint faulting trends, emphasizing the influence of the fibers on the abovementioned. It was found that fibers can improve joint performance and decrease faulting in thin concrete pavements. Regarding the ultra-thin pavements, no conclusion was possible to be drawn on the contribution of the fibers. [ABSTRACT FROM AUTHOR]

The unavoidable transverse non-uniformity of settlement and moduli for part-fill and part-cut subgrade may have some critical impact on concrete pavement structures, hence, some structural optimisations of pavement based on the working conditions of subgrade are essential. In this study, on account of the practical working conditions of part-fill and part-cut subgrade, a finite element model of concrete pavement structure on part-fill and part-cut subgrade developed previously was conducted to analyse the effects of slab thickness, slab concrete modulus of rupture, tie bar diameter and tie bar spacing. Furthermore, improvement methods and strategies were analysed and proposed for the four parameters respectively with fatigue cracking design life under loading as the target and maximum stress at the bottom of slab as the criterion. The results verified the feasibility of incorporating non-uniformity of modulus and settlement into the design phase of concrete pavements on part-fill and part-cut subgrade. Additionally, concrete pavement parameter optimisation priority should be given to concrete modulus of rupture, slab thickness, followed by tie bar diameter and spacing. It can provide a useful reference for designing concrete pavement structures on part-fill and part-cut subgrade. [ABSTRACT FROM AUTHOR]

Full depth repair remains to be the favored pavement restoration method amongst the common rehabilitation and repair activities carried out for concrete pavements. This paper explores the prospects of utilizing behavioral benefits of Self-Compacting Concrete (SCC) with the inclusion of Wollastonite micro-fiber, for repair and rehabilitation of concrete pavements. Wollastonite was included in the study by replacing fine aggregates in concrete mix in proportions 10%, 20%, 30%, 40% and 50%. The mixes were investigated for their behavioral properties including flow ability, resistance to segregation, filling ability and mechanical properties i.e. compressive strength, flexural strength, water absorption and hardened density. The rehabilitation prospect of concrete pavements with SCC was studied by conducting a joint repair study on pavement prototypes specially designed and tested for the purpose. It was found that the concrete mix with Wollastonite were more cohesive and workable which is attributed to its acicular structure and lustrous appearance. During the rehabilitation study, prototypes representing a jointed section of concrete pavement were repaired with SCC mixes. The prototypes repaired with SCC having Wollastonite micro-fiber at levels of 10%, 20% and 30% reported better flexural strength in comparison to those repaired with conventional concrete or with plane self-compacting concrete mix. [ABSTRACT FROM AUTHOR]

Abstract The west section of the Governor Mário Covas São Paulo Metropolitan Road Ring was opened to traffic in 2002. The original pavement was a jointed plain concrete pavement with dowelled joints and a design flexural strength (or modulus of rupture) of 4.5 MPa. Premature failure of the concrete slabs was observed not only by engineers and users, but also reported by the media. Concrete slabs soon started being demolished and replaced. Many of the removed slabs were taken to a nearby recycling plant for crushing. However, the resulting recycled concrete aggregate was not used in the manufacturing of the new slabs. There were concerns that the potential presence of detrimental chemical substances had caused the early deterioration of the slabs. If that were true, using recycled aggregates obtained from the original concrete could result in the same issues in the new mix. This paper describes a feasibility study on recycling the original concrete for use as aggregate in new concrete slabs. The first goal was to verify the presence of fluorite as detrimental substance in the existing concrete because there was a suspicion among concrete technologists engaged on mixture design during the construction. Chemical analysis using X-ray fluorescence spectrometry did not show the presence of chemical components detrimental to concrete durability. Therefore, the second goal was to accept the material for recycling and discuss mix proportions, strength, stiffness, fracture toughness, and fatigue. Although some of the concrete properties were affected by the inclusion of recycled aggregates in the mix, the results indicate that it is possible to use recycled aggregates produced from the original concrete to cast new concrete slabs, however requiring greater thicknesses. The fatigue performance of recycled mixtures points out the demand for thicker and eventually more expansive design solutions.

Concrete pavement is accompanied by two major functional properties, namely noise emission and friction, which are closely related to pavement surface texture. While several technologies have been developed to mitigate tire-pavement noise and improve driving friction by surface texturization, limited information is available to compare the advantages and disadvantages of different surface textures. In this study, a state-of-the-art and state-of-the-practice review is conducted to investigate the noise reduction and friction improvement technologies for concrete pavement surfaces. The commonly used tests for characterizing the surface texture, skid resistance, and noise emission of concrete pavement were first summarized. Then, the texturing methods for both fresh and hardened concrete pavement surfaces were discussed, and the friction, noise emission and durability performances of various surface textures were compared. It is found that the next generation concrete surface (NGCS) texture generally provides the best noise emission performance and excellent friction properties. The exposed aggregate concrete (EAC) and optimized diamond grinding textures are also promising alternatives. Lastly, the technical parameters for the application of both diamond grinding and diamond grinding & grooving textures were recommended based on the authors' research and practical experience in Germany and the US. This study offers a convenient reference to the pavement researchers and engineers who seek to quickly understand relevant knowledge and choose the most appropriate surface textures for concrete pavements.

This study comprehensively evaluates the field applicability of hydraulic modified sulfur (HMS) as a concrete additive. We assessed the microstructural characteristics, mechanical properties, and durability performance of HMS at various replacement ratios in a laboratory setting. In addition, a field study was conducted by removing an existing conventional concrete pavement measuring (6000 × 12,000 × 70 mm, W × L × T) and overlaying it with HMS concrete. The experimental results revealed that HMS enhanced the mechanical and durability performance when used as a cement replacement at rates below 9%. These results satisfied the quality control standards and performance criteria specified in the Korean standard specification for cement-concrete pavements. The comparative analysis revealed that HMS concrete outperformed conventional concrete mixtures by 62.6% in sulfuric acid penetration depth, 14.8% in compressive strength retention after sulfuric acid immersion, and 53.1% in chloride-ion penetration resistance. Furthermore, no anomalies were detected during the 3-month follow-up period.

Concrete infrastructure is vulnerable to damage such as spalling. Spalling leads to chloride penetration, which causes internal corrosion, weakens structural stability and durability, and increases the likelihood of additional cracks or damage, consequently necessitating repair. Existing repair methods do not consider the factors that affect damage in the repaired areas, so additional damage can occur, making monitoring necessary to identify these factors. Nevertheless, existing studies have not adequately addressed the monitoring of internal conditions within concrete, making it difficult to manage such damage effectively. Accordingly, in this study, a monitoring system was developed using building information modeling (BIM) and the Internet of Things (IoT) to better identify internal changes in concrete pavements. Employing embedded sensors to measure temperature, humidity, and stress within the concrete, our system uses Dynamo scripts for real-time data visualization within BIM. Validated against the ASTM D8292 standard, this system captures and analyzes environmental impacts on concrete. This integration facilitates the detection of internal changes, allowing for the real-time visualization of these impacts. This study can help establish repair plans by identifying factors affecting concrete, contributing to preventive maintenance, potentially reducing maintenance costs, and enhancing the sustainability of concrete infrastructures.

Before conducting pavement rehabilitation, the concrete pavement performance evaluation is more than necessary to assess the strength and analyze the internal condition. To evaluate the modulus performance of concrete pavement and provide theoretical support for subsequent maintenance and rehabilitation, the SASW (Spectral-Analysis-of-Surface-Waves) method, a non-destructive testing method based on surface waves, was used to determine the modulus of three in-service concrete pavements. At the same time, FWD (Falling Weight Deflectometer) testing and on-site coring were carried out at the measuring points. Through the analysis of modulus results measured in the field, it was found that the SASW method can accurately obtain the elastic modulus of the concrete layer and base layer. Compared with the concrete modulus measured by FWD, the modulus measured by the SASW method was closer to the uniaxial compressive modulus. Moreover, since the SASW method has the ability to provide gradient modulus varying with depth and determine the pavement thicknesses, it is reasonable to recognize the location of the inherent distress based on the region where the modulus suddenly decreases within one layer. The comprehensive evaluation of concrete pavement condition, including the modulus value and internal distress recognition, has the capability to assist in determining the design of overlay asphalt thickness and material. [ABSTRACT FROM AUTHOR]

Embankments and retaining walls are integral parts of the bridge system and provide a smooth transition from lower elevations (i.e., roadways) to higher elevations (i.e., bridge decks). Performances of pavement structures supported on embankments or retaining walls are directly related to their conditions. This paper presents a comprehensive case study of the evaluation of pavement structures supported on an in-service mechanically stabilized earth (MSE) wall that showed significant distresses, such as lane separation, faulting, lane settlement, and tilting of the MSE wall. The conditions of the pavement structures were evaluated via visual observations, falling weight deflectometer (FWD) tests, and coring through pavement structures. The conditions of the MSE wall were evaluated through dynamic cone penetrometer (DCP) tests, cone penetration tests (CPTs), LiDAR surveys, and soil borings. Detailed analysis of the data obtained in this study provides valuable insights into potential distress mechanisms. [ABSTRACT FROM AUTHOR]

A magnetite mortar microwave-absorbing layer that could be applied to concrete pavement was studied to improve the deicing efficiency of roads in low-temperature conditions. The magnetite cement mortar (MCM) was prepared by using magnetite as the main absorbing material. The microwave absorption ability and heating characteristics of MCM with different magnetite contents were investigated. In addition, the mechanical and durability properties of MCM were studied. Furthermore, a microwave-absorbing layer was prepared and tested for outdoor field deicing. The result showed that adding magnetite effectively improved the mechanical strength and frost resistance of MCM, which could improve its load resistance and service life. Meanwhile, the microwave absorption ability of MCM was also improved with the increase of magnetite content. At the microwave frequency of 2.45 GHz, the average heating rate of MCM with 80% magnetite content was 2.27 times than that of ordinary cement mortar. In addition, the content of magnetite was positively correlated with the heat transfer ability of MCM. Magnetite conversion of microwave energy into heat energy could quickly transfer heat to the whole mortar system. The field deicing test verified the feasibility of efficiently deicing a magnetite mortar microwave-absorbing layer in low temperature conditions. [ABSTRACT FROM AUTHOR]

In full-joint concrete roads, as a result of hydropumping under the pavement caused by rain water or drainage water filtered from the joints, cavities are formed after softening in the foundation layer and then the emergence of fine grains to the surface. As a result of the discharges in the foundation layer, cracks that occur in the joint areas during the repeated passage of vehicles can shorten the service life of the concrete pavement. Within the scope of this study, the performance of fiber-added concrete, which has been in demand in the concrete sector in recent years, has been investigated as a solution to these deteriorations in concrete roads. For this purpose, the behavior of plates prepared with fiber-reinforced and plain concrete under cyclic loading was investigated experimentally with dynamic loading, based on the discharge occurring under the pavement. Parameters such as the effect of fibers on cracking in concrete, the amount of load carried in the collapse zone, and displacement performance were investigated. In the light of the results obtained, it has been determined that fiber reinforced concrete is more resistant to cracks in the joint area than plain concrete. [ABSTRACT FROM AUTHOR]

The falling weight deflectometer (FWD) test is a common non-destructive testing method for evaluating the structural capacity of pavements. At present, data processing of the FWD test mainly focuses on the deflection data, while paying less attention to the deflection-time history. Because a FWD is equipped with impulse loads and geophones, which allow for the generation and capture of surface wave signal propagation, it is hypothesized that Rayleigh wave dispersion theory can be applied to calculate the modulus profile along the pavement depth by analysing the dispersive properties of the deflection signal measured during FWD tests. To test this hypothesis, we develop a new methodology for the FWD test and data analysis, referred to as the FWD dispersion curve method. We first introduce the concept of the new method, followed by an illustration of the procedure and the experimental set-up. Case studies on three concrete pavement segments are then presented to evaluate the effectiveness of the FWD dispersion curve method. Modifications to the existing FWD device are further recommended for the impact loading sources and signal collection process so that the modulus of a much shallower layer, such as the concrete slab and upper asphalt layers, can be obtained. This article is part of the theme issue 'Artificial intelligence in failure analysis of transportation infrastructure and materials'. [ABSTRACT FROM AUTHOR]

This study investigated the effects of mixture proportions and vibration levels on the physical properties, durability and performance of concrete used in Korean pavements. The strength and durability characteristics varied depending on the mixture proportions and level of vibration, and samples with fly ash (i.e., F-CON) did not meet the strength and durability criteria when low levels of vibration were applied. Therefore, intermediate or higher levels of vibration should be applied to satisfy strength and durability criteria. Meanwhile, there was little difference in the performance tests (i.e., skid resistance, surface abrasion, and IRI) of concrete pavements depending on the mixture proportions and vibration levels. However, the sample with an intermediate level of vibration had a relatively higher performance than the other samples. [ABSTRACT FROM AUTHOR]

The use of carbon-fiber heating cables (CFHC) to achieve effective melting of snow and ice deposited on roads is a method used worldwide. In this study, tensile and compressive tests have been conducted to analyze the mechanical properties of the CFHC and assess whether the maximum tensile and compressive strengths can meet the pavement design specifications. In order to study the aging produced by multiple cycles of heating and cooling, in particular, the CFHC was repeatedly heated in a cold chamber with an ambient temperature ranging between -20°C and +40°C. Moreover, to evaluate how the strength of the pavement is affected by its presence, the CFHC was embedded at different depths and concrete blocks with different curing ages were subjected to relevant compression and splitting tensile tests. Numerical simulations based on the ANSYS software have also been performed and compared with the outcomes of the static loading tests. The results show that the CFHC embedded in the concrete does not affect the compressive splitting tensile strengths of the pavement. Overall, the CFHC meets the conditions required for continued use in road ice melting applications. [ABSTRACT FROM AUTHOR]

This study evaluated the mechanical properties and abrasion resistance of the concrete pavement when cement was replaced by the blast furnace slag (BFS) and Gilsonite at levels of 20%, 25%, and 30%, as well as 5%, 7%, and 9%, respectively. For this purpose, a total of ten mixing designs were made and cured for 28 days. The results showed that the compressive strength of mixtures containing two additives decreased. In contrast, the BFS20-G7 (i.e., sample containing 20% BFS and 7% Gilsonite) mixture satisfied the proposed minimum compressive strength. However, the flexural strength and tensile splitting of the BFS20-G7 containing 20% BFS and 7% Gilsonite increased by about 4 and 7 percent. The Wide Wheel Abrasion Test results showed that the mixture containing 20% BFS-7% Gilsonite increased the abrasion resistance by about 5% and 17% in 100 and 300 revolutions, respectively. Conclusively, using BFS20-G7 in low traffic areas such as park and driveway can be suggested. [ABSTRACT FROM AUTHOR]

The construction of rigid pavements using conventionally vibrated concrete consumes a significant amount of energy as it requires rigorous vibrations. This also requires a high number of laborers and creates noise during construction. Thus, a new kind of concrete called semi-flowable self-consolidating concrete (SFSCC) for pavement construction using slip-form paving technology is reviewed in this article. The SFSCC requires no energy for compaction as it gets compacted under its self weight. It also renders shape stability in the fresh state which is critical to expedite the construction in slip form concreting. The review focuses on the need, evolution, and requirement of the ingredient materials, mix design, and methods for testing the properties of SFSCC. Further, the utilization of industrial wastes in the construction industry and the production of self-consolidating concrete are discussed. The literature on the effect of different materials on the properties of such concrete and field studies in this context are discussed. Lastly, its suitability as pavement construction material either in normal rural roads or in low-volume village roads is discussed in the Indian context. The review reveals that relatively less amount of study on SFSCC in general and as a pavement material in particular is available in the literature and pursuant to this, creates a wide scope of research.

The destructive effects of global warming have attracted attention to the optimal using of resources and recycling. Therefore, slag has been considered as a solution in various industrial sectors including the road construction. Also, among the new materials, cement carbon nanostructures which can improve the concrete mechanical properties and resistance are used. These nanostructures are produced through Chemical Vapor Deposition method during the cement production process on the type II cement. In this study, it is aimed to improve the mechanical properties and resistance of concrete pavements with slag and cement carbon nanostructures. The results showed that using 66% slag and 5% cement carbon nanostructures (SC66N5) have been shown the best performance in concrete pavements. Increasing the amount of slag and carbon nanostructures enhance the compressive strength, flexural strength, tensile strength, chlorine passing current and durability against freezing and thawing cycles, and decrease permeability and water absorption percentage. The results showed that in SC66N5 28-day sample, the compressive strength (52%), flexural strength (32%), tensile strength (53%), chlorine passing current (88%) and passing ultrasonic pulse velocity after freezing and thawing (7%) are increased with respect to the cement concrete sample. Furthermore, the permeability (46%), water absorption percentage (45%), weight loss after freezing and thawing cycles (78%) are reduced in comparison to the cement concrete sample. The results revealed that using slag and cement carbon nanostructures improve the durability of concrete pavements.

In seasonally frozen regions, concrete pavement is exposed to cycles of freeze-thaw and erosion from de-icing salt, which can lead to unfavorable service conditions and vulnerability to damage. This paper examines the compressive strength, flexural-tensile strength, abrasion resistance, permeability, and spacing factor of concrete, taking into account the impact of various curing conditions, de-icing salt solutions, and mass fractions on the concrete’s freeze-thaw resistance. Two test methods, the single-face method and the fast-freezing method, were used to comparatively analyze the freeze-thaw resistance of concrete. The analysis was based on the surface scaling, water absorption rate, mass loss rate, relative dynamic elastic modulus, and relative durability index. The results indicate that the presence of salt solution significantly worsened the degree of concrete damage caused by freeze-thaw cycles. The use of freeze-thaw media, specifically sodium chloride (NaCl), calcium chloride (CaCl2), and potassium acetate (KAc) at mass fractions of 5%, 4.74%, and 5%, respectively, had the greatest impact on the surface scaling of concrete. However, their effect on the water absorption rate was inconsistent. When the freeze-thaw medium was water, the concrete’s relative dynamic elastic modulus and relative durability index were 9.6% and 75.3% higher, respectively, for concrete cured in 20 °C—95% RH conditions compared to those cured in 0 °C—50% RH conditions. We propose a comprehensive relative durability index (DFw) by combining the results of two methods of freeze-thaw tests. The DFw of concrete cured in 0 °C—50% RH conditions was 83.8% lower than that of concrete cured in 20 °C—95% RH conditions when exposed to a freeze-thaw medium of 5% mass fraction NaCl solution. To evaluate the salt freeze-thaw resistance of concrete pavement, it is recommended to use surface scaling and DFw together.

Homogenized micro-crack crushing can fully retain the bearing capacity of concrete pavement, but local weak road base needs to be reinforced before being directly overlaid with hot-mixed asphalt. Therefore, indoor tests were conducted to study the mechanical properties of slag-based geopolymer as a grouting material for weak road base, and the morphology and influence of polymerization reactants were observed. Concurrently, on-site grouting tests were conducted to study the grouting effect. The results show that the compressive strength, flexural strength and bonding strength of slag-based geopolymer all increase with age. The maximum compressive strength and flexural strength of the geopolymer at 28 d were 18.88 MPa and 6.50 MPa, respectively. The maximum flexural bonding strength at 14 d was 4.58 MPa. As the ratio between water and slag powder increased, the compressive strength and flexural strength gradually decreased, while the bonding strength first increased and then decreased. In the range of ratios of water to slag powder from 0.26 to 0.28, the above three strengths were relatively high, and the compressive shear bonding strength was the highest when the ratio of water to slag powder was 0.28. The shrinkage of the slag-based geopolymer increases with the increase in ratio of water to slag powder, and the porosity also increases, resulting in a decrease in compactness after consolidation. When the ratio of water to slag powder was 0.28, the reactant was mainly a gel-phase material, and the shrinkage crack of the consolidated geopolymer was relatively small. After grouting the weak road base of the concrete pavement, the voids at the bottom of the concrete pavement slab were effectively filled, and the deflection of the pavement slab was significantly reduced. The average deflections of monitoring line I, monitoring line II and monitoring line III decreased by 49%, 41% and 54%, respectively, after grouting. After solidification, the slag-based geopolymer was distributed in layers, which further compacted the road structure layer and improved the bearing capacity. [ABSTRACT FROM AUTHOR]

With the development in construction technology, dowel bars insertion in the joint plain concrete pavement (JPCP) is practiced using dowel bar inserters (DBI). Although DBI, can reduce the probability of the single dowel bar misalignment, wrong construction practices, gap graded concrete mixtures, inappropriate calibration of DBI may result in the complete assembly of dowel bars being misaligned. Most previous studies investigated the effect of single dowel misalignment, which may not describe the stress-state when entire dowel bars assembly is misaligned. Further, experimental investigations may be expensive to investigate the effect of dowel bars misalignment. In this direction, to understand the impact of uniform misalignment of dowel bars assembly, a 3D finite element model was developed considering vertical and longitudinal translation type of misalignments. The model results indicated that the vertical translation misalignment results in excessive tensile stresses in the concrete at the joint. This may lead to tensile fatigue failure resulting in dowel looseness. Further, the longitudinal translation resulted in higher compressive stresses, which may result in the crushing of the concrete due to repeated application of wheel loads. Both the cases of misalignment resulted in lower load transfer efficiency than no-misalignment cases. The study found that critical stresses in the concrete at the joint are a function of the type of dowel misalignment. [ABSTRACT FROM AUTHOR]

Large-scale repair works (LSRW) are expensive and time-consuming, and therefore cannot be carried out simultaneously for all deteriorated pavements; hence, they are performed based on urgency. In Korea, the re-modeling index (RMI) program versions 1.0 and 2.0 were developed to predict the urgency of the LSRW on expressway concrete pavements. In this study, version 3.0 of the RMI program was developed to address the drawbacks found in version 2.0 of the program. The model used in the program was improved by using the equivalent single-axle load instead of the annual average daily traffic used in the previous version, to consider the damage to pavement caused by heavy vehicles. In addition, another model was modified by combining the winter climate conditions with the annual deicing salt usage, which was used as the only variable considering the environmental factors in the previous version. The international roughness index and surface distress prediction models, which were not separated by pavement type in version 2.0 of the program, were separated into jointed concrete pavement and continuously reinforced concrete pavement. The logic for predicting future RMI was also reasonably improved. In addition, the logic of categorizing the entire expressway concrete pavement section into homogeneous sections was objectively improved for more effective LSRW. Consequently, for 2023, the Korea Expressway Corporation selected for LSRW those homogeneous sections that were evaluated as urgent by the RMI3.0 program. [ABSTRACT FROM AUTHOR]

Many traditional methods for the repair and rehabilitation of concrete pavements require meticulous construction processes with specialized equipment and long material curing periods in order to develop adequate strength and durability prior to returning the pavement to service. This paper summarizes the results of research projects conducted by the U.S. Army Engineer Research and Development Center in order to develop innovative pavement repair procedures and evaluate numerous commercial repair materials that can produce fast long-lasting repairs that facilitate the rapid re-opening of critical pavement infrastructure to traffic. This paper summarizes methods used for the certification and selection of suitable concrete pavement repair materials. In addition, this paper outlines the key activities included in expedient concrete repair processes. Thus, this paper provides a valuable summary of state-of-the-art concrete repair procedures and materials for the rapid and effective repair and rehabilitation of concrete pavements. [ABSTRACT FROM AUTHOR]

Concrete pavement growth can cause blow-ups and other pressure-related issues, such as concrete buckling and crushing at the transverse cracks or joints. In addition, these issues result in damaged to adjoining structures, such as bridge abutments, decks, and access structures in the pavement. However, available theoretical solutions and methods for evaluating pavement growth and predictions of concrete pavement blow-up are considerably limited. In this study, therefore, the pavement growth and blow-up analysis model was developed to predict the blow-up potential due to concrete pavement growth. This model considered factors such as the pavement structure and materials, climatic conditions, configuration of expansion joint, base friction characteristics, geometric imperfection, rotational stiffness of joints, and design reliability. In addition, the pavement growth and blow-up analysis model can be used to predict the service life of expansion joints and the blow-up occurrence time by considering the factors affecting it. Using the developed model, various sensitivity analysis was performed to investigate the factors affecting the potential concrete pavement growth and blow-up occurrence. It was found that the factors of substrate type, coefficient of thermal expansion, precipitation, and alkali–silica reaction had a significant effect on pavement growth and blow-up occurrence times. [ABSTRACT FROM AUTHOR]

Featured Application: Concrete Pavement Solar Collector Technology. The urban heat island (UHI) effect occurs when cities and towns warm up more than the surrounding rural areas because they have more structures and less vegetation and soil. The issue can be lessened by implementing a pavement solar collector (PSC) system, which converts heat from the pavement's surface into thermal energy. In this work, the authors analyze the effect of pipe depth (85 mm to 50 mm) and spacing (200 mm to 100 mm) on the efficiency of heat extraction from the surface while taking pavement structural performance into account using the ANSYS Fluent program. The modeling approach was validated against the previous studies. According to the findings, a concrete water harvesting system may achieve the maximum outlet temperature with the least impact on traffic loading by using a distance of 100 mm and a depth of 85 mm. The load's impact is 51% less than that of the model that predicted the highest outlet temperature, and the outside temperature is reduced by 3.9%. The outcomes here demonstrated that concrete might be employed in the PSC system as an alternative to asphalt. [ABSTRACT FROM AUTHOR]

In order to further enhance the reinforcing effectiveness of polypropylene (PP) fibers on pavement concrete, waterborne epoxy (WBE) was introduced in this research and its effect on the flexural properties and freeze–thaw resistance of PP-fiber-reinforced concrete was evaluated. Compressive-strength tests, flexural-strength tests, three-point bending tests, freeze–thaw cycling tests and a scanning electron microscopic observation were carried out to analyze mainly the influence of WBE on the flexural properties and freeze–thaw resistance of PP-fiber-reinforced concrete. WBE contents of 0, 5%, 10%, 15% and 20% by weight of the cement were employed. The experimental results indicated that WBE was beneficial to improving the flexural properties of PP-fiber-reinforced concrete. With increasing content of WBE, the flexural strength and the peak load showed significant increases. Although a slight degradation in the abovementioned flexural parameters was observed when the WBE content was above 15%, the deflection at the peak, the fracture energy and the fracture toughness still showed an upward trend. In addition, the freeze–thaw resistance of PP-fiber-reinforced concrete was improved remarkably with the increasing addition of WBE content, leading to smaller mass loss and higher residual flexural strength. Moreover, microstructural images revealed that with the addition of WBE, the PP fiber/concrete interfacial bonding was effectively improved, and the concrete matrix tended to be denser as well, which provided higher resistance for crack initiation and propagation. In consideration of maximally improving the flexural properties of PP-fiber-reinforced pavement concrete, and while ensuring the compressive strength and meeting the freeze–thaw requirements, it was recommended that the content of WBE in PP-fiber-reinforced concrete should be 15%. [ABSTRACT FROM AUTHOR]

Thickness detection of concrete pavement is a critical step in construction completion acceptance and serves as an important metric for subsequent pavement performance evaluations. The crux of thickness evaluation lies in determining the interface reflection echo propagation sound time. Based on the acoustic impedance difference between the surface layer and contact layer, pavement can be classified into two types: large-difference and small-difference. By examining the singularity of the detection signal, we employed the improved correlation coefficient method and the wavelet transform maximum value method to identify the interface reflection echo sound time. This study refines the traditional correlation coefficient method by using the surface direct wave as the reference signal, simplifying the signal analysis process. In actual detection, for the type of concrete pavement with large differences in acoustic impedance, the average relative error between the improved correlation coefficient method and the core drilling method can be reduced to 1.7%; for the type with small differences, the average relative error of the detection results obtained using the wavelet transform modulus maximum method can be reduced to 1.9%, showcasing high accuracy. [ABSTRACT FROM AUTHOR]