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Roadways are the main transportation mode in Brazil for both cargo and people. This strong dependence on road transport makes paving highways extremely important for the country's development. A common way to recover deteriorated pavement is through a superficial reinforcement called overlay. The whitetopping overlays are made of Portland cement concrete. The technique basically consists of building a concrete pavement over the existing asphalt pavement. The existing pavement acts as a sub-base for the concrete overlay. The addition of fibers to concrete has been increasingly frequent, especially for industrial floors and pavements, bringing longer performance life for same traffic, climate and concrete strength. The fibers promote the improvement of several characteristics of the concrete paste, such as the increase in post-cracking toughness, energy absorption, and fracture energy. This work evaluates the flexural response of composite beams of concrete and asphalt layers and the influence of adding fibers to the concrete. An experimental program is set and supports the development and validation of a finite element numerical model. The numerical model is then applied to a parametric study where tendifferent concrete mixes with different types of fibers and contents are analysed. Steel and synthetic fibers are used. The composite beams are simulated indicating the concrete mixes that best supported loads in the post-cracking regime, with some mixes managing to maintain around 90% of the peak load for large crack openings. [ABSTRACT FROM AUTHOR]

The continuously reinforced concrete pavement (CRCP) system grapples with challenges such as non-uniform transverse crack patterns and the need for substantial reinforcement. Field research on the Belgian CRCP sections along motorway E313 indicates that active cracking induced by partial surface saw-cuts consistently leads to transverse crack patterns. This study introduces an innovative modification to the CRCP: the actively reinforced concrete pavement design (ARCP). The ARCP leverages partial surface saw-cuts to reduce reinforcement needs by replacing continuous-length steel bars with partial-length counterparts. The main objective of the present study is to develop a 3D finite element (FE) model capturing the active cracking behavior of ARCP under realistic external temperature variations. Comparative analysis with CRCP considers early-age crack patterns, crack strain development, and the distribution of maximum steel stress for different steel ratios (0.67%, 0.75%, and 0.85%). FE simulation results align with field data, indicating that ARCP exhibits similar early-age cracking behavior to CRCP but with a significant 24 to 42% reduction in total reinforcement. This innovation presents a promising avenue for addressing CRCP challenges while optimizing material usage in pavement construction. [ABSTRACT FROM AUTHOR]

Superload vehicles (SLs) are typically defined as vehicles having a gross vehicle weight (GVW) greater than 890 kN. SLs often consist of unique axle configurations that may cause significant damage to pavements. Research has been mainly limited to SLs on asphalt pavements, therefore the effect of SLs on concrete pavements is not well established. In this study, fatigue stresses in concrete pavements were quantified for a database of pavement structures and SLs to identify critical conditions that contribute to fatigue damage. A series of load pulses were constructed from a database of finite element results to identify conditions and locations within the slab for peak stress development. Tensile stress greatest in thin pavements with a stiff base layer and large positive temperature gradients subjected to tandem axle SLs. Fatigue damage was calculated for the critical cases using several damage models, and significant variation was found between models based on inputs used. [ABSTRACT FROM AUTHOR]

On the shear load‐bearing capacity of thin‐walled box girders with unreinforced joints in the webs As part of the LT bridge construction method (L: Longitudinal, T: Transversal), which is being developed at TU Wien, thin‐walled hollow concrete box girders are used longitudinally and are combined with deck slab elements and in‐situ concrete. Due to the construction process, unreinforced joints remain in the webs of these box girders, while the bottom and deck slabs can be continuously reinforced due to the in‐situ concrete layers. The question arose as to how this joint configuration affects the shear load‐bearing capacity of the box girders. In order to gain a fundamental understanding, two large‐format test specimens, one with joints in the webs and one without, were investigated experimentally. The shear force capacity of the girder with joints corresponded approximately to the one of the girder without joints, showing that it was possible to transfer significant shear forces despite the joints. The joint opening proved to be characteristic for the shear load‐bearing behaviour, as the stirrups adjacent to the joint act like a suspension reinforcement. A local increase in the stirrup reinforcement in this area is therefore recommended. Non‐linear finite element analyses were carried out to analyze the effects of post‐tensioning, as used in the LT method, on the load‐bearing behavior. It was shown that the load‐bearing behavior of the post‐tensioned girder with joints largely corresponds to the one without joints. [ABSTRACT FROM AUTHOR]

Few investigations have considered comprehensive deformation constraints when calculating thermal stress of concrete slab. In this paper, the comprehensive and refined non-linear deformation constraints model of concrete slab is firstly proposed by setting non-linear spring elements at bottom and side of the slab and the capacity of shear load transfer across joints is considered as well. The results show that thermal stresses calculated by refined non-linear deformation constraints model are in good consistent with experimental results. The foundation reaction modulus has little effect on thermal stresses, but has a significant effect on gap between slab and its foundation. The stiffer base results in higher curling stresses at bottom of slab, and the types of base have an important effect on frictional resistance in horizontal direction at bottom of slab. The larger shear stiffness of joints will increase thermal stresses and shear force along joints but decrease deflections of slab. [ABSTRACT FROM AUTHOR]

Transverse joints are introduced in jointed plain concrete pavement systems to mitigate the risk of cracks that can develop due to shrinkage and temperature variations. However, the structural behaviour of jointed plain concrete pavement (JPCP) is significantly affected by the transverse joint, as it creates a discontinuity between adjacent slabs. The performance of JPCP at the transverse joints is enhanced by providing steel dowel bars in the traffic direction. The dowel bar provides reliable transfer of traffic loads from the loaded side of the joint to the unloaded side, known as load transfer efficiency (LTE) or joint efficiency (JE). Furthermore, dowel bars contribute to the slab's alignment in the JPCP. Joints are the critical component of concrete pavements that can lead to various distresses, necessitating rehabilitation. The Swedish Transport Administration (Trafikverket) is concerned with the repair of concrete pavement. Precast concrete slabs are efficient for repairing concrete pavement, but their performance relies on well-functioning dowel bars. In this study, a three-dimensional finite element model (3D-FEM) was developed using the ABAQUS software to evaluate the structural response of JPCP and analyse the flexural stress concentration in the concrete slab by considering the dowel bar at three different locations (i.e., at the concrete slabs' top, bottom, and mid-height). Furthermore, the structural response of JPCP was also investigated for several important parameters, such as the joint opening between adjacent slabs, mispositioning of dowel bars (horizontal, vertical, and longitudinal translations), size (diameter) of the dowel bar, and bond between the slab and the dowel bar. The study found that the maximum LTE occurred when the dowel bar was positioned at the mid-depth of the concrete slab. An increase in the dowel bar diameter yielded a 3% increase in LTE. Conversely, the increase in the joint opening between slabs led to a 2.1% decrease in LTE. Additionally, the mispositioning of dowel bars in the horizontal and longitudinal directions showed a 2.1% difference in the LTE. However, a 0.5% reduction in the LTE was observed for a vertical translation. Moreover, an approximately 0.5% increase in LTE was observed when there was improved bonding between the concrete slab and dowel bar. These findings can be valuable in designing and evaluating dowel-jointed plain concrete pavements. [ABSTRACT FROM AUTHOR]

This paper presents an effort to address urgent issues associated with semitruck platooning. The weigh-in-motion data were first examined to determine the characteristics of naturally formed semitruck platoons. A safety-based two-vehicle platoon model was then utilized to determine the critical headways for assessing the safety of semitruck platooning in various driving scenarios. The possibilities for passenger vehicles to cut into semitruck platoons were assessed using actual vehicle headway data. Finally, the potential impacts of semitruck platooning on typical interstate highway pavements were assessed using finite element analysis. Most semitruck platoons consist of two to three vehicles. An optimal platoon gap of 0.94 s was identified for connected and automated semitruck platooning. The potential impacts of truck platooning on concrete pavement were negligible for a platoon gap greater than 0.2 s. The maximum possible impact was less than 4% in terms of the service life reduction for interstate asphalt pavement. [ABSTRACT FROM AUTHOR]

The large-scale mining of magnesite generates substantial quantities of magnesite mine tailings (MMT), which pose a significant threat to soil, water, and air quality. Utilising cement-treated MMT as a subgrade material presents a promising solution to address this environmental challenge. However, the existing mechanical-empirical design methods cannot be directly employed due to the uncertainties associated with the various design parameters particularly the behaviour of cemented MMT. This research introduces a novel reliability-based MEM design method to design flexible pavements incorporating cemented MMT as subgrade. A three-layered flexible pavement configuration, with a middle granular layer sandwiched between the top bituminous layer and the bottom stabilised subgrade, was examined. The response surface model and finite element model were developed to determine the fatigue and rutting strains of the pavement. Monte Carlo simulation was adopted to compute reliability. Further, a sensitivity analysis was performed to probe the contribution of input parameters on the reliability of pavement. The developed methodology was illustrated with a case study. Reliability analysis revealed that the cemented MMT pavement achieved reliabilities of 97.44% and 96.27% for fatigue and rutting criteria, respectively, under a design traffic load of 30 million standard axles (msa). Additionally, the sensitivity analysis identified the modulus of elasticity of the granular layer and bituminous layer as the most critical input variables. Thus, the developed design methodology for pavements incorporating MMT enables the engineers to design MMT-based flexible pavements considering the uncertainties. [ABSTRACT FROM AUTHOR]

Patching is a common technology used in repairing asphalt-pavement potholes. Due to the differences in material properties between patched- and unpatched-asphalt mixtures, significant strain and stress concentrations could be induced; thus, further cracks and interfacial debonding distress could be caused. As a remedy, the strain and stress concentrations can be alleviated by utilizing optimum patching shapes. Therefore, this paper employed finite element methods (FEM) to deeply analyze the mechanical performance of patched-asphalt pavements embedded with different patching shapes. Three patching shapes, these being rectangular, stair, and trapezoid, were considered for use in pavement pothole repairs based on two- and three-dimensional finite element models. In the two-dimensional models, Top-Down and Bottom-Up crack propagations were simulated to assess the anti-damage performance of the patched pavements with different patching shapes. In addition, the thermal stress behaviors within patched-asphalt pavements were simulated using the two-dimensional model to analyze the performance of the patched pavements during the cooling process in construction. In addition, interface-debonding performance was simulated for the patched-asphalt pavements using three-dimensional models. In light of the simulation results, engineers are expected to better understand the mechanism within patched pavements and to improve the quality of the pavement patching. [ABSTRACT FROM AUTHOR]

In many countries, linear infrastructures (roads, railways or airports) are the most efficient and advantageous means of transport for citizens. Some of these infrastructures, such as roads or runways, are made of concrete, and as they are exposed to repeated loads and weather conditions, cracks are forming and spreading throughout the pavement. Several repair techniques have been applied to ensure their continued use under various types of traffic. The repair technique of adding lightweight welded mesh or geosynthetic layers seems to be a suitable solution, given their mechanical and aesthetic performance. This paper presents an experimental study on the effect of wire mesh and geogrids on the reinforcement of rigid concrete pavements. Twenty-four (24) specimens of concrete slabs, unreinforced and reinforced with a combination of geogrid sheets and wire mesh, were fabricated and tested in four-point bending. Validation of the experimental results was obtained by applying the finite element method, using a commercial software. Non-destructive in situ tests with a heavy deflectometer (HWD) were carried out on the central part of a rigid runway located in southern Algeria (arid zone), before and after its reinforcement with geogrids. It was found that geogrids are more effective than wire mesh in terms of tensile strength, stress and displacement reduction and downward crack propagation, with percentages ranging from 15 to 30%. [ABSTRACT FROM AUTHOR]

Over the years, thicknesses of continuously reinforced concrete pavement (CRCP) increased to accommodate rising truck traffic. With a fixed percentage of longitudinal reinforcement relative to the concrete cross-sectional area, thicker slabs necessitate more reinforcement and reduced bar spacing, potentially hindering consolidation. To address this issue, two-mat steel design was implemented in Texas for pavements with thickness of 330 mm (13 in.) or larger. Performance evaluations of thick CRCPs revealed that horizontal cracking developed at the depth of reinforcement where one-mat steel was placed, while no horizontal cracking was observed where two-mat steel was used. Pavement responses with one-mat and two-mat reinforcements with different depths were analysed by three-dimensional modelling with a finite element analysis (FEA) programme for the wide range of environmental loadings. Maximum concrete vertical tensile stresses around longitudinal reinforcement at transverse crack area are a good indicator of horizontal cracking potential; those stresses were evaluated, along with concrete stresses at top of the slab, which are responsible for top-down transverse cracking. The results show that the two-mat design causes higher concrete stresses at the top of the concrete slab and lower concrete stresses around the longitudinal reinforcement, leading to increased transverse cracks and a reduction in horizontal cracking potential. [ABSTRACT FROM AUTHOR]

In this study, a three-dimensional (3D) finite element model (FEM) consisting of an asphalt concrete (AC) overlay on top of jointed plain Portland cement concrete (PCC) slabs was developed to investigate the mechanism of the crack initiation of traffic-induced reflective cracking. Strain values at the bottom of AC overlay were the primary response obtained from the simulation results to represent the damage induced in the AC layer. Different bonding situations between the two layers, traffic load locations, material properties and thicknesses of the AC layer were taken into consideration. The analysis results show that the dominating strain for damage is dependent on the bonding condition between the AC and PCC layers. When the AC layer is completely bonded with the PCC layer, the damage will initiate firstly at the top of the joint corner between the PCC slabs to deteriorate the bonding, then the AC bottom will be susceptible to bending strain. It was observed that the most critical load location for modeling the case of fully bonded overlays is related to the AC thickness while in the case of partially bonded overlays, the most critical load location is always located on the top of one side of the PCC joint. [ABSTRACT FROM AUTHOR]

Traditional jointed plain concrete pavement (JPCP) systems cannot be reused after grouting fast-setting materials in the dowel slot. To achieve demountability, a removable dowel bar connection system is proposed in this paper. The severe stress concentration occurring in JPCP systems is mitigated by applying a stainless steel ring at the pavement joint surface. In the monotonic loading tests, different stainless steel ring thicknesses, lengths and the stainless steel tube thicknesses were considered. The effect of the stainless steel ring on the structural performance of the removable dowel bar connection system was studied in terms of the failure mode, the deflection response, ductility and the strain distribution and development. Besides, after being validated against experimental test results, the developed finite element model was used to conduct the extended parametric analysis, in which a close relationship was found between the ultimate load and the stainless steel ring length. To prevent the localised crushing failure, the maximum compressive stress at the joint surface was compared with the allowable bearing stress under service load. By using FEA data, an empirical equation was finally proposed to predict the ultimate loads of specimens with the proposed connection system. [ABSTRACT FROM AUTHOR]

Although Friberg's theoretical analysis is frequently used to analyse the dowel bar-concrete interaction in jointed plain concrete pavement (JPCP) system, the compressive stress concentration at top and bottom of the dowel slot cannot be explained with this theory. In this paper, two modifications including the elastic deformation of concrete support and the stress distribution factor considering the sinusoidal contact stress distribution are proposed to improve the Friberg's theoretical analysis. Modifications are then validated against elastic finite element analysis (FEA) results in terms of the contact stress distribution, the maximum compressive stress as well as the range of compression zone. To further investigate the maximum compressive stress at the joint surface, relevant parameters including the dowel bar diameter, the modulus of elasticity of concrete as well as the joint width are studied through elastic finite element analysis (FEA). Apart from proposing referenced moduli of dowel support, a close relationship between the modified modulus of dowel support and dowel bar diameter is also found and verified. Finally, differences between the Friberg's theoretical analysis and the modified method are summarised in a flow chart at the end of the paper. [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]

The cross-tensioned concrete pavement (CTCP) has good bearing capacity, anti-crack ability and convenient construction characteristics due to the cross-tenioned prestressed strands placed inside the concrete. In order to study the mechanical response of pavement in construction process, an assembled monolithic structure for CTCP has been proposed and its mechanical response was analyzed through full-scale experiments and finite element model. The results of full-scale experiments show that the longitudinal and transverse compressive strain of concrete respectively exceeds 40μϵ and 20μϵ in the area of laying cross-tensioned prestressed strands with increase of the number of cross-tensioned strands. The end of CTCP is one of the weak areas, which may produce certainly transverse tensile stress. The results of finite element model show that the transverse tensile stress in ending region is mainly affected by the angle of cross-tensioned prestressed strands and its ratio. There is transverse tensile stress at the end of the pavement when the angle of cross-tensioned prestressed strands is small and its ratio is large, which can be offset by arranging transverse prestressed strands. Furthermore, an empirical formula to calculate transverse prestressed strands ratio at the end of pavement is given based on the results of finite element simulation. [ABSTRACT FROM AUTHOR]

Accurate pavement design and evaluation requires the execution of response analysis. Pavement materials' behavior does not necessarily conform to the assumptions of the multi-linear elastic theory usually adopted during pavement analysis. In particular, the unbound granular materials located in the base and sub-base layers behave in a nonlinear elastic manner, which can be captured through advanced constitutive modeling of their resilient modulus. The finite element method enables us to code constitutive models and quantify potential variations in pavement responses because of different mechanistic assumptions. In this study, variations in response are investigated for a typical structure of a flexible pavement considering the nonlinear anisotropic behavior of the unbound materials together with their initial stress–strain state. To demonstrate the impact of their behavior on the outcome of pavement analysis, variable asphalt concrete layer thicknesses and moduli are assumed, such that they cover a large spectrum of roadways. It was found that pavement responses can be calculated up to 3.5 times higher than those retrieved from the conventional linear analysis. This comparison means that the alterative mechanistic modeling of the unbound granular materials can be proved to be more conservative (i.e., leading to higher strains) in terms of pavement design and analysis. From a practical perspective, this study alerts pavement scientists and engineers engaged in pavement design to a more reliable performance prediction, which is needed to bridge the gap between advanced modeling and routine analysis. [ABSTRACT FROM AUTHOR]

The performance of a joint in airport rigid pavements can be evaluated using load transfer efficiency (LTE). Various existing methods to calculate LTE using different parameters were reviewed in this paper, illustrating how the performance of a joint that performs well is underestimated. To address this concern, a new parameter obtained from the deflection time history output of HWD (Heavy Weight Deflectometer) is being proposed to calculate LTE. Field measurements and FEM (Finite Element Method) modeling were employed to validate the proposed calculation in comparison with the conventional calculations of LTE. Based on the statistical analysis, the proposed method shows low variance and error compared to the conventional calculation of LTE in airport pavements. Moreover, core samples were collected along the tested joints to verify if the calculated values manifest the internal condition of the joints. The calculated results from the proposed LTE show a good agreement not only with the surface condition of the joints, but also with the collected core samples. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) composite is increasingly used as a repair material for civil engineering infrastructure, including runway, road pavement, and buildings. Evaluation of polyurethane grouting (PUG) material is critical to achieve a desirable maintenance effect. This study aims to evaluate the flexural behavior of normal concrete repaired with polyurethane grout (NC-PUG) under a three-point bending test. A finite element (FE) model was developed to simulate the flexural response of the NC-PUG specimens. The equivalent principle response of the NC-PUG was analyzed through a three-dimensional finite element model (3D FEM). The NC and PUG properties were simulated using stress–strain relations acquired from compressive and tensile tests. The overlaid PUG material was prepared by mixing PU and quartz sand and overlayed on the either top or bottom surface of the concrete beam. Two different overlaid thicknesses were adopted, including 5 mm and 10 mm. The composite NC-PUG specimens were formed by casting a PUG material using different overlaid thicknesses and configurations. The reference specimen showed the highest average ultimate flexural stress of 5.56 MPa ± 2.57% at a 95% confidence interval with a corresponding midspan deflection of 0.49 mm ± 13.60%. However, due to the strengthened effect of the PUG layer, the deflection of the composite specimen was significantly improved. The concrete specimens retrofitted at the top surface demonstrated a typical linear pattern from the initial loading stage until the complete failure of the specimen. Moreover, the concrete specimens retrofitted at the bottom surface exhibit two deformation regions before the complete failure. The FE analysis showed good agreement between the numerical model and the experimental test result. The numerical model accurately predicted the flexural strength of the NC-PUG beam, slightly underestimating Ke by 4% and overestimating the ultimate flexural stress by 3%. [ABSTRACT FROM AUTHOR]

A transfer function is the main model of a design program that correlates mechanistically calculated damage to a pavement with the actual field distress. In this study, a pavement condition index (PCI) model that reflects environmental and traffic loads was developed as a transfer function for a design program for airport concrete pavements. Seven runways from five airports in Korea, for which design data were available, were selected as target runways, and their design, traffic, and weather data were collected. The minimum tensile stress of the slab generated by environmental loads and the maximum tensile stress induced by combined environmental and traffic loads were calculated by conducting a three-dimensional finite element analysis. The cumulative fatigue damage to the target runways was calculated by substituting the climatic conditions and traffic volume into the fatigue model, which considered the minimum and maximum tensile stresses. The PCI, which was uniformly and varyingly distributed according to pavement age, was adopted as the indicator of actual field distress, whereas the previously used structural condition index was mostly 100 because no structural distress occurred, regardless of the pavement age. The PCI model was established via multi-regression analysis to predict field PCIs using mechanistically calculated cumulative fatigue damage and pavement age as independent variables. The actual and predicted PCIs of the target airports were compared to validate the PCI model. [ABSTRACT FROM AUTHOR]

During the rigid pavement design, the concrete slab working on the base/subbase and subgrade is usually modeled as the slab on the elastic foundation. However, the non-uniform distribution of materials in the base or subgrade layers naturally exists in real conditions and should be considered. In this paper, a finite element method for calculating concrete pavement slabs on an elastic foundation with non-uniform stiffness distribution is developed. This study applies 4-node finite elements and Mindlin plate theory to formulate the finite element equations. The results predicted by the proposed approach are verified analytically. Calculation examples are conducted with the practical settings to investigate the influence of slab and foundation stiffness parameters on the slab displacement. [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]

Due to Infrastructure development city streets are being covered with concrete pavements in which it makes the pavement surface impermeable. During monsoon period, the importance of counter action against the stormwater runoff develops a stress among the Central and the State Governments of India. It also attracts the attention of the Road and Transport officials mainly because of the difficulties faced with poor drainage system during heavy intensity of rainfall. The productive application of pervious concrete includes its usage for light volume transportation and it also diminishes the additional design for stormwater drainage. This concrete also holds potential to accommodate shoulders in heavy traffic roadway transportation. The behaviour of pervious pavement under various loading scenario can be well understand using Finite Element Method Analysis (FEMA). For primary assessment of pervious concrete (PC) as pavements, computer modelling software is preferable and economical comparing to ground evaluation after installation. In this paper, a EverFE (Finite Element Analysis) tool has been used to develop and determine the loading characteristics of pervious pavement based on the experimental values obtained through preliminary studies. [ABSTRACT FROM AUTHOR]

Lunar landing pad is an important infrastructure on the lunar surface and is used to improve landing safety and mitigate dust problems caused by launch and landing. It will be subjected to the dynamic mechanical loading from the footpads of the spacecraft and the retrorocket plume loading. Only the former was considered in this study, and the latter will be explored in future studies. Prefabricated module assembly method is one of the most feasible construction methods. The assembly pattern, size, and thickness of the prefabricated modules are important factors that affect the structural performance of the lunar landing pad. In this study, three forms of mechanical interlocking were identified for an assembled lunar landing pad (ALLP) according to the interlocking form. In addition, a simple shape was designed for each form. Interlocking concrete blocks were fabricated, and a plate loading test (PLT) was conducted to evaluate the structural performance of the assembled concrete block pavement (ACBP). By comparing the numerical and experimental results, corresponding finite element (FE) models of the plate loading tests were developed and validated. Finally, an FE model to evaluate the structural performance of the ALLP based on the validated ACBP FE model was developed. The effects of the size and thickness of the interlocking modules and load position on the structural performance of the ALLP were further studied. The results indicated that the thickness of the modules had a greater influence on the structural performance than the load position and size of the modules. This study is expected to provide a reference for the design and construction of lunar landing pads. • Three forms of mechanical interlocking were identified for the lunar landing pad. • Finite element models of assembled interlocking lunar landing pad were developed. • Structural performance of assembled interlocking lunar landing pad was studied. [ABSTRACT FROM AUTHOR]

Waste clay brick (WCB) accounts for a dominant fraction of construction and demolition waste, and it is necessary to explore the sustainable measures of it as a construction material in civil engineering. This paper evaluated the effect of WCB content on the performance of cement-stabilized recycled concrete aggregate (RCA) in pavement base/subbase applications. Based on the microscopic tests and laboratory tests of the aggregate, the compaction test, unconfined compressive strength (UCS) test, indirect tensile strength (IDT) test, resilient modulus test, freeze and thaw cycling test, and drying shrinkage test were conducted with the different WCB content cement-stabilized RCA/WCB blends. A trial pavement section was paved based on the test results, and finite element analysis (FEA) was carried out to investigate the effect of cement-stabilized RCA/WCB blends on asphalt pavement. It is concluded that the potential utilization of pozzolanic properties of WCB plays an important role in pavement applications. The moderate content of WCB fine aggregate is beneficial for the UCS, IDT, resilient modulus, freeze and thaw cycling, and drying shrinkage of cement-stabilized RCA/WCB blends, while the content of WCB coarse aggregate influences the test results to a worse degree. Besides, the performances of the trial pavement section comply with the pavement design and specifications. Furthermore, the results of FEA indicate that the maximum vertical displacement and von Mises stress increase with the reduction of the resilient modulus. This paper gives systematic research on the effect of WCB content on cement-stabilized pavement base/subbase applications, and it may improve the potential application of cement-stabilized RCA/WCB blends in pavement base/subbase. [ABSTRACT FROM AUTHOR]

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The falling weight deflectometer (FWD) detection system benefits from its outstanding characteristics of no damage, fast speed, and high precision. The warping deformation of cement concrete pavement occurs due to the temperature difference along the depth of the slab, which makes FWD detect different results under different temperature fields. In this study, we systematically carried out the cement pavement's temperature field and deflection test. The experimental data were analyzed to obtain the temperature variation law of the top and bottom of the pavement slab every day. By establishing a three-dimensional finite element model of cement pavement with a multi-layer elastic foundation type, the influence of the temperature difference at the bottom of the slab on the deflection of the center point of the slab corner load under different working conditions, different seasons, different loads and whether there is polymer filling in the void area was studied. We summarize the correlation between the temperature difference and the influence coefficient and propose the cement pavement void identification and polymer grouting effect evaluation method considering the temperature effect. [ABSTRACT FROM AUTHOR]

Solar pavements are a new type of pavement structure that harvest energy from the sun and have been widely investigated in recent years. A critical step toward the acceptance and development of solar pavement structures is investigating their mechanical response, which is conducted in this study. Here, a typical pavement structure with functional photovoltaic, cement concrete, base, subbase, and subgrade layers was selected. This is one of the most acceptable forms of the solar pavement structure. A numerical simulation of the solar pavement was conducted by establishing a 3D model using the finite element software ABAQUS. The effects of the vehicle critical load position, elastic modulus, geometric size, linear expansion coefficient of the photovoltaic panel (PVP), and cement concrete slab (CCS) thickness on the mechanical response of the solar pavement under vehicle and temperature loadings were investigated. The results indicated that the critical load position of the solar pavement in the middle of the long side of the concrete slab was the same as that of the traditional concrete pavement. The PVP parameters influenced the mechanical response in the following order: elastic modulus, linear expansion coefficient, and geometric size. By increasing the CCS thickness from 0.20 to 0.28 m, the CCS load stress decreased by 15%; however, the curling stress increased significantly from 0.85 to 1.97 MPa. An increase in the PVP linear expansion coefficient caused the curling stress of the solar pavement to first decrease and then increase. A linear expansion coefficient of 1 × 10–5 resulted in minimum curling stresses of 0.42 and 1.70 MPa for PVP and CCS, respectively. [ABSTRACT FROM AUTHOR]

To investigate the deflection, maximum stress, maximum strain, and failure of pavement joints of conventional and remix concrete pavement models. Nine model pavement slab specimens has been cast and statically loaded using hydraulic jack, load cell on loading frame assembly. Two concrete mix design grades and three concrete remixing procedures were chosen and fixed. This work checks the effect of remix concrete on rigid pavements, taking into account time lag (t in hr.) of Concrete (THC) and the blend ratio (r). The methods were a regular mixed with traditional procedures and a remix mixture with selfing and crossing methods. The results of a 3D finite element analysis with ANSYS simulation are compared to experimental trials. By adding a higher graded fresh concrete to the old and partially set concrete, there is improvement in the compressive strength, quality of the concrete, and modulus subgrade reaction, according to this study. [ABSTRACT FROM AUTHOR]

Abstract From the late 1960’s airport engineers developed special paving material for arresting aircraft gears in event of overrun as a partial extension of a runway end safety area. Such pavement surface material, inverting a general concept, should be crushed over the first pass of gear wheels resulting the aircraft to sink and being promptly arrested resulting in abrupt loss of velocity, preferability avoiding loss of lives and injuries as well as with minimum risks for the airplane structural integrity. Herein is analyzed and discussed the possible application of pervious concrete for such a task by simulating an actual situation (Congonhas airport) and understanding the structural effects on the crushable concrete surface layer, pointing out stresses, deflections and required strengths for the material. Simulations regarded the critical aircraft A 320-200 as well as fire-fighters cars over the pavements. Analysis complied to Federal Aviation Administration requirements for non-standard pavement structures as well simulation of stresses trough the finite element method for medium-thickened plates. Compressive stresses along with flexural excessive stresses, besides predictable punching shear stresses allowed to conclude by the feasibility of using low strength pervious concrete as alternative for engineered material to be built as arresting system.

Concrete pavements are subjected to the combination of moisture transport, heat transport and traffic loading. A hygro-mechanical 3D finite element model was created in OOFEM software in order to analyse the stress field and deformed shape from a long-term non-uniform drying. The model uses a staggered approach, solving moisture transfer weakly coupled with MPS viscoelastic model for ageing concrete creep and shrinkage. Moisture transport and mechanical sub-models are calibrated with lab experiments, long-term monitoring on D1 highway and data from 40 year old highway pavement. The slab geometry is 3.5×5.0×0.29 m, resting on elastic Winkler-Pasternak foundation. The validation covers autogenous and drying strain on the slab. The models predict drying-induced tensile stress up to 3.3MPa, inducing additional loading on the slab, uncaptured by current design methods. [ABSTRACT FROM AUTHOR]

Due to the large-scale use of materials in highways, the sustainability of materials has attracted considerable interest for years. In this respect, significant effort has been spent investigating the use of recycled aggregates in concrete pavements. This study has been carried out to fill the gap in the structural performance of recycled aggregate concrete pavements. First, properties of concrete mixtures, produced with virgin, recycled concrete and recycled brick aggregates were experimentally measured, and the results were compared. Then, finite element analyses were done by following a novel methodology that considers the well-known previous works. Results showed that replacement of coarse aggregates with recycled aggregates decreases the mechanical properties in various amounts. Due to the resulting performances, for the same slab thickness, decreased maximum stress, increased deflection and stress ratio values were found for recycled aggregate mixtures. Additionally, higher thicknesses and material requirements were found for recycled aggregate concrete for a similar life. Despite the decreased performance and increased material requirements, the use of recycled aggregates in pavements can still be a viable alternative for countries with limited natural resources and landfills. Therefore, based on the findings, several important discussions and suggestions were presented for future works. [ABSTRACT FROM AUTHOR]

To investigate the shear-lag effect in the main girder of a composite twin-box girder cable-stayed bridge during construction, a full-bridge model and a local spatial model were established using the finite element software MIDAS/Civil and ABAQUS, respectively, for the main span of the Chibi Yangtze River Bridge in Hubei Province, China, as an engineering example. On this basis, the shear-lag effect in the composite twin-box girder under multiple typical construction conditions was analysed through numerical simulation, and the accuracy of the model was verified by field measurements at the construction site. Results demonstrate that as the balanced cantilever construction progresses, the stress in the deck slabs near the junction of the anchor plate and the outer web of the side box girder and at the location of small longitudinal beams changes substantially. However, the stress at other girder sections is gradually uniformly distributed, the shear-lag coefficient tends to be stable, and a phenomenon of positive and negative shear-lag effect conversion occurs in the deck slab sections of the main girder. [ABSTRACT FROM AUTHOR]

Years of research have been devoted to developing a tool to model and analyze the behavior of rigid pavements. A major component of the new design approaches is the threedimensional Finite Element Method (FEM), which caused a breakthrough in rigid pavement analysis. The current study used FEM to analyze a rigid pavement composed of a concrete slab layer and a subgrade. The impact of the depth of the concrete slab layer on vertical stresses and displacements was studied with the ABAQUS software. Three different thicknesses were chosen, 20, 25, and 28cm, while the thickness of the remaining paving layers remained unchanged. According to the study results, the top of the concrete slab layer had an increase in stress of approximately 88% when its thickness increased from 20 to 28cm, whereas the top of the subgrade layer had a decrease of about 21% in stress. The change in vertical stress at the top of the subgrade layer was 46% for a thickness of 20-25cm and 14.8% for 25-28cm. The percent of the reduction in vertical stress at the top of the concrete slab layer was 13.2% and 1.8% for thicknesses of 20-25 and 25-28cm respectively. Vertical displacement in the middle of the horizontal distance under the tire print was reduced by 14%, 12%, and 24% when the concrete slab layer increased from 20 to 25, from 25 to 28, and from 20 to 28cm respectively. [ABSTRACT FROM AUTHOR]

A composite separator layer in Portland cement concrete pavement, formed by a lower bearing layer and micro surfacing, was seldom used in airport pavement, but it has great application potential. This paper studied the properties of the composite separator layer and its benefits for pavement. The basic properties investigated in the study were resilient modulus and interlayer property between the separator layer and concrete. The resilient modulus of the micro surfacing was tested to calculate the modulus of the whole separation layer. The interlayer shearing test was done on core specimens using a self-developed facility that can apply load in the normal direction. Shearing test results show that temperature affects the shape of the shearing curve and normal stress linearly affects the stable shear force. Additionally, an in-situ erosion test was carried out to prove the anti-scouring property of the separator layer. Furthermore, a finite element model (FEM) model was established to study the influence of the composite separator layer. The FEM employed the modulus test results and the measured interlayer characteristic. The interlayer characteristic was simplified into a two-stage constitutional model. Monitored data on the mechanical response of the pavement structure in an airport validated the FEM model. Results show that the separator layer reduces the chance of contraction crack under the sudden temperature drop in the concrete slab before sawing. FEM results show that though the separator layer slightly increases the tensile stress of concrete, the tensile stress is greatly reduced if the slab develops voids in the future. The most significant benefit of the separation layer is it reduces the chance of void occurrence so that the lifespan of pavement with a separator layer is improved compared to regular pavements which frequently have voids beneath the slab. With the finite element model results and cumulative fatigue life equations, the separator layer was estimated to elongate the pavement service life for years, depending on the time voids appear. [ABSTRACT FROM AUTHOR]

This study aimed to determine the material properties and the thickness of the layers of an unbonded jointed plain concrete pavement design over a deteriorated flexible pavement that lost its service capability. Maximum principal stresses occurring under the concrete pavement should not exceed the modulus of rupture of the concrete. Three-dimensional finite element analyses using ANSYS (Release 18.1 SAS IP, Inc.) software were carried out with the Taguchi method. The most reliable solution for the pavement design was investigated with whole configuration axle loading that reflects the realistic traffic situation. The stress values under the concrete slab due to the positive temperature gradient neglected in the American Association of State Highway and Transportation Officials (AASHTO) method were also investigated. The concrete slabs are exposed to these stresses for longer than the axle loads. Temperature distributions throughout the thickness of the concrete slab were calculated with the bilinear formulas suggested in the study. Axle loadings were applied on both the pavement edge and corner to reflect the most critical loading condition in the pavement design. The critical axle type was found to be 1.2. It was observed that a 0.15 m concrete thickness was appropriate for the concrete class, joint spacing and hot mix asphalt (HMA) elasticity modulus levels used for the 1.22, 1.122, and 1.2 + 111 axle types, but it was not appropriate for the 1.2 axle types. The slab thicknesses calculated with the AASHTO method, and the finite element method were found to be close to each other. It was determined that the concrete thickness significantly affected the maximum principal stress, with a performance statistic (S/N) value of 1692 for the 1.2 axle type. This was followed by the modulus of elasticity of the concrete with an S/N value of 0.356, the modulus of elasticity of the existing flexible pavement with an S/N value of 0.244, and the concrete joint spacing with an S/N value of 0.105. A practical design guide was recommended to extend the service life of a highly deteriorated flexible pavement with the construction of unbonded jointed plain concrete. [ABSTRACT FROM AUTHOR]

The authors proposed a new precast RC column-steel beam (RCS) joint with whole column-section diaphragm, aiming to address the shortcomings including bearing failure and difficulty in prefabrication of the RCS joint details available in the existing literature. Due to its unique details, the proposed RCS joint may have a dissimilar force-transferring mechanism from the conventional beam-through type RCS joint. Moreover, the effect of various parameters on this novel joint was still unclear by limited test results. The objective of this study was to clarify the shear mechanism of the proposed joint and the impact of critical parameters. Specimens with different axial load ratios and thickness of parallel FBPs were tested under cyclic loading. The results showed that the increase in axial load ratio and thickness of parallel FBPs improved joint strength in this test. A detailed three-dimensional finite element (FE) model was developed and verified using the experimental results. The difference in the force transferring between the proposed joint and conventional beam-through RCS joints was explained in detail based on the numerical results. The dowel action of longitudinal column bars were evident in the proposed joint and the orthogonal FBPs were ineffective in activating the inner concrete strut. A parametric study was further conducted. The impacts of width of parallel FBPs, thickness of orthogonal FBPs, and axial load ratio were investigated. The joint strength linearly increased with the width of parallel FBPs. A parabolic distribution of shear stress in the parallel FBP section was obtained, while the yield zone was concentrated in the central area of the parallel FBP. The ductility could be improved with the thickness of orthogonal FBPs when the thickness was less than 10 mm. Further increasing the thickness of orthogonal FBP beyond 10 mm did not significantly affect the overall joint behavior. The joint may attain the optimal shear strength when the axial load ratio is between 0.3 and 0.4. The modeling approach in this study could be adopted as an effective tool to assess joint behavior. Moreover, the conclusions obtained by numerical study potentially promoted the application of the proposed joint. • A comprehensive numerical study on a new proposed RCS joint with whole column-section diaphragm was presented. • A finite element model that reasonably revealed the joint behavior was developed. • The differences in force-transferring mechanism between the proposed joint and traditional joint were discussed. • The effects of essential parameters on joint behavior were evaluated. [ABSTRACT FROM AUTHOR]

Engineered Cementitious Composites (ECC) are considered a promising alternative for the construction of durable pavements. The objective of this study was to evaluate the effects of plasticity and flexural fatigue behaviour of ECC on pavement performance. A low-cost ECC using low fibre content (1.5% volume fraction), locally-available river sand and a high level of cement replacement with class F fly ash (75% by weight) was investigated. The ECC demonstrated a pseudo-strain-hardening (PSH) behaviour at all curing ages. Furthermore, as curing progressed, the tensile and flexural strengths increased; yet, ductility decreased. The flexural fatigue performance of the ECC was significantly superior to that of regular concrete. Finite Element Analysis (FEA) was integrated with flexural fatigue experimental results to establish a thickness vs. cycles to failure (T-N) relationship. In developing the T-N relation, the effect of ECC plasticity was accounted for by proposing a stress equivalency function to convert plastic stress into an equivalent linear elastic stress. From the T-N curves, it was determined that the original ECC T-N curve (without implementing the stress equivalency function) greatly overestimated the numbers of the cycle to failure for thicknesses below ~60 mm as this curve starts exhibiting an asymptotic behaviour with respect to N. [ABSTRACT FROM AUTHOR]

This study aims to investigate the mechanical characteristics of precast concrete runway cement pavement under the wheel load of aircraft, and to promote the construction of precast concrete pavement. In this study, based on the elastic layered Boussinesq calculation theory and ABAQUS finite element numerical model, the distribution law of stress, the displacement of the aircraft wheel load acting on different positions of the pavement slab, the influence of the added dowel bar on the pavement slab, and the load transfer between adjacent slabs are obtained. The results revealed that when the wheel load of the aircraft acts on the edge and joint of the slab, the vertical stress of the adjacent slab edge is largest, followed by the middle of the slab, and then the joint; the maximum vertical stress is 0.295 MPa. Furthermore, the aircraft wheel load on the slab edge, and the joint vertical displacement, is larger than that of the slab middle, and the adjacent slab edge transverse displacement attenuation coefficient is approximate. Moreover, the load transfer efficiency of the dowel bar was lower when the wheel load of the aircraft was closer to another unloaded slab. Finally, the validity and sensitivity of the simulation results are verified by laboratory test data. These results can provide a reference and suggestions for the design and production of the precast concrete pavement of airport runways. [ABSTRACT FROM AUTHOR]

Since the mid-2000 s, longitudinal tinning has been applied to concrete pavements of expressways to improve the comfort and safety of road vehicle users. However, in certain longitudinal tinning sections, lateral vibrations occur during driving, which poses a safety hazard. This paper analyzes the cause behind this problem and proposes a longitudinal texturing specification that can minimize lateral vibration. To perform this analysis, the accelerations of driving vehicles and the degree of lateral vibration transmitted to panels in the vehicles were evaluated for each longitudinal texture applied in South Korea. Structural analysis was also conducted for the lateral force and moment according to the tire tread profile and longitudinal texturing specifications using the finite element method. In addition, field investigation, indoor drivability evaluation, and field application were performed to evaluate the optimal longitudinal texturing specification. The results indicate that the texture designated as 2 × 3 × 19 mm is the optimal longitudinal texture on hardened concrete pavement. However, because this specification is difficult to apply to fresh concrete, 3 × 3 × 16 mm is proposed as the optimal longitudinal texture owing to its excellent performance in the panel survey and in structural analysis. [ABSTRACT FROM AUTHOR]

Rigid pavements have high compressive strength and low flexural strength due to the brittleness of concrete. This leads to the formation of cracks easily under the applied loads of vehicles; therefore, the design of concrete pavements usually leads to an increase in the high thicknesses. Hybrid steel fibers are used in concrete to increase flexural strength and minimize crack formation. Using concrete with steel fibers in pavements reduces the required concrete thickness. In recent decades, the application of the finite element method to predict the behavior of rigid pavements has increased. This study investigates the influence of hybrid steel fiber on the behavior of rigid pavements; a finite element modeling approach is used to simulate the case study. Several parameters are entered and investigated in this study, including the proportion mix of hybrid fiber concrete (HFC), which contains 0.2% macro synthetic fibers and 0.68, 0.8, and 0.96% of steel fibers, compressive strengths of 25, 35, and 45 MPa, slab thicknesses of 150, 200, and 250 mm, and the load of the tandem axle at the edge of mid slab on the Winkler foundation. The ATENA software package is used to perform a nonlinear finite element analysis. Thirty-six rigid specimen pavements with dimensions of 3600 × 3600 mm were modeled in this investigation. The results showed that the addition ratio (0.68 + 0.2)% of hybrid fibers is more effective in improving the load bearing capacity with a slab thickness of 150 mm and 25 MPa compressive strength. [ABSTRACT FROM AUTHOR]

In this study, a set of numerical simulation analysis methods for studying the dynamic response of runway under the action of aircraft taxiing load are presented. An aircraft-runway coupled vibration model was established, and the runway pavement roughness was taken as the vibration excitation source; then, the aircraft taxiing dynamic load was obtained. A three-dimensional finite element model of the runway was established, and the vertical dynamic displacement (VDD) response and its variation law of the runway under different void conditions were studied under the action of the dynamic load of a taxiing aircraft. In addition, using wavelet packet transform, the acceleration signals at different positions of the pavement slab under the sliding load were decomposed into three layers. The relationship among the wavelet packet energy ratio (WPER), the wavelet packet energy entropy (WPEE) of each frequency band, and the void under the pavement slab was obtained. The results show that the established model could quickly and accurately solve the aircraft taxiing dynamic load. In the case of a slight void, the VDDs in the runway center and under the main landing gears had negative exponential and logarithmic relationships with the reduction coefficient of the dynamic elastic modulus of the base layer, respectively. When there was a severe void, the pavement slab was separated from the base layer. The VDDs in the runway center and under the main landing gears were exponentially and linearly related to the slab's void area, respectively. The vibration signals were extracted at three measuring points, and the wavelet packet energy characteristics of the signals were compared and analyzed. It was found that the WPER and WPEE of the vibration signals in the void area of the slab corner could better reflect the void state of the slab bottom. [ABSTRACT FROM AUTHOR]

The performance of cast-in-place cement concrete pavement can be greatly influenced by the surrounding environment and the quality of construction, and it requires longer curing time before opening to the traffic. The precast cement concrete pavement has the potential to address the disadvantages of using the cast-in-place cement concrete as the pavement surface material, and it also provides an alternative solution for the rapid repair of pavement damage. The current study aimed to assess the influences of geometry of full-scaled precast concrete slabs with various load transfer joint types. A numerical analysis was conducted using the finite element method to analyze the mechanical responses of the single and double slabs in accordance with the elastic thin-plate theory and the Specifications for Design of Highway Cement Concrete Pavement. Under the premise of determining the most unfavorable load position for different mechanical parameters, the mechanical response regularity under the critical loads was determined. The precast concrete pavement slab with dimensions 4 m long, 3 m wide and 0.28 m thick exhibited better mechanical responses when considering the maximum deflection and flexural stress as the evaluation index. The results indicated that the variation of joint forms has marginal influences on the maximum deflection and displacement transfer coefficient. When considering the maximum flexural stress and load transfer coefficient of the precast slabs, the circular tongue-and-groove joint form was recommended for application. [ABSTRACT FROM AUTHOR]

Because of favorable mechanical properties, deformation resistance and being conducive to environmental protection, honeycomb fabricated plastic pavement slabs are highly recommended these years. At present, most studies focus on the performance of plastic materials, however, the dimension optimization of fabricated plastic pavement slab is rarely mentioned. In this paper, an optimized geometry of the honeycomb pavement slab was determined through finite element analysis. Mechanical response of honeycomb slabs with different internal dimensions and external dimensions were explored. Several dimension factors were taken into consideration including the side length, rib thickness, the thickness of both top and bottom slabs of honeycomb structure and the length, the width and the thickness of the fabricated plastic slab. The results showed that honeycomb pavement slab with 6 cm bottom slab, 12 cm top slab,18 cm side length and 6 cm rib thickness is recommended, additionally, an external dimension of 4 m × 4 m × 0.45 m is suggested. Then, the mechanical responses of this optimized fabricated plastic slab were further investigated. Significance of different influencing factors, including wheel load, elastic modulus of plastic material, base layer thickness, soil foundation modulus and base layer modulus were ranked. [ABSTRACT FROM AUTHOR]

Accurate monitoring of concrete pavement support condition is critical for pavement maintenance. This paper proposed a novel support condition monitoring method using distributed optical fiber sensing (DOFS) technology. The DOFS-based method can precisely monitor the support condition on a larger scale. Single-mode optical fiber with a particular rubber encapsulation was applied as a compression sensor, measuring the interfacial compression status between the concrete pavement slab and the pavement base through a compression-to-strain transfer mechanism. Finite element analysis (FEA) and laboratory experiments were conducted to compression-to-strain transfer mechanism. It was revealed that the average compression-to-strain transfer efficiency reached over 1900 μϵ/mm. The design parameters of the compression sensor were also provided based on the FEA and experiment results. A quasi-distributed sensing system was developed to capture the two-dimensional support condition by connecting the sensors in a particular path. The sensing system's effectiveness was demonstrated by conducting full-scale tests and using the pressure-sensitive film (PSF) as a comparison. The test results showed a great deal of applicability for support condition monitoring under concrete pavement. [ABSTRACT FROM AUTHOR]

This paper presents comprehensive research work on the crack initiation behavior of Semi Flexible Pavements (SFP) with the help of a one-way coupled multiscale modelling approach. The study focuses on elucidating the influence of layer interface conditions on potential cracking patterns under different temperature conditions. By integrating material properties at both local (mixture) and global (pavement) scales using a local de-homogenization approach, the interlocking effect was addressed within the asphalt binder's mesoscale properties. CT-image based mesostructure was employed to reconstruct the Representative Volume Element (RVE). Cohesive Zone Model (CZM) was utilized to simulate cracking initiation within the RVEs, with simulation results validated against practical engineering inspections. Additionally, a potential macroscopic failure index was introduced for SFP. It was found that the typical macroscopic failure indexes utilized for AC pavement may not be suitable for SFP due to the higher degree of heterogeneity. Analysis showed that SFP layer's coarse aggregate and cement grout at the bottom may experience compressive stress, while asphalt binder beneath the tire load may face high tensile stresses. Regardless of the interface conditions, top-down cracking was found to be the dominating failure mode in SFP. Besides, the vulnerable area in bonded interface SFP shifts from under tire load to the adjacent area with the rise in pavement temperature, while bottom-up cracking may appear only in unbonded interface SFP under low temperature conditions. Subsequent analysis demonstrated that top-down cracking is prominent in bonded interface SFP, especially at higher temperatures, compared to unbonded interface SFP. It is expected that critical observations for SFP highlighted above will certainly help in understanding critical failure modes and, hence, designing and constructing durable SFP structures. • A one-way coupled multiscale modelling approach considering interlocking effect was developed. • The interlocking effect was addressed using a local de-homogenization method. • The cracking initiation form of SFP was simulated and validated by pavement inspection. • A potential macro-mechanical failure index was proposed for SFP. [ABSTRACT FROM AUTHOR]