Pavement Reinforcement Research Articles

Rehabilitation and reinforcement of cracked pavements using crack sealers and composite patches

Cracking is a significant concern for pavements and should be appropriately treated during road, highway, and runway rehabilitation. This study investigates the behavior of asphaltic materials under tensile and shear loading modes in intact, fractured, and repaired conditions. With this aim, several methods and materials are utilized for repairs, such as poring adhesive into the crack (using bitumen, neat epoxy resin, and polymer concrete adhesives) and patching the crack with textile (by glass fiber and epoxy resin or bitumen). These tests were conducted at +10 °C, with a three-point bending loading configuration, the same as the actual loading configuration of pavements. Criteria such as failure load, failure work, and post-failure work, as well as failure patterns, were assessed to assess the effectiveness of repairs. Numerical analysis was also performed, and a constitutive model was presented. The ultimate tensile capacity of the cracked specimen is measured at 63 % lower than the intact condition (778 N). The ultimate tensile load of the bitumen-repaired specimen is higher than that of the cracked specimen, but it is still 11 % lower than that of the intact condition. The ultimate tensile capacity of epoxy resin repaired and polymer concrete repaired specimens are 88 % and 79 % higher than the intact specimen (about 1400 N). The ultimate tensile load of the fabric patch reinforced specimen that used bitumen as the adhesive is 38 % higher than the intact specimen (1075 N), while for the case of using the epoxy resin adhesive, this value is 258 % (2788 N). Observations of tensile failure patterns show that, because bitumen is viscoelastic, failure in bitumen-repaired specimens happens in bitumen necking mode and starts at the repaired crack tip. In other cases, the failure occurred far from the pre-crack plane.

Design and mechanic analysis of asphalt pavements with subgrade reinforced using the AEMC software

The Construction industry is one of the major contributors to waste generation in various aspects of its production chain. Construction and Demolition Waste (CDW) stand out, generated by the lack of reuse and inadequate disposal, as well as a lack of knowledge about the potential uses of this material. Thus, this article presents a methodology for the use and design of asphalt pavement layers that use CDW as coarse aggregate and/or infrastructure layer. In this context, a mechanical analysis of the material used as a subgrade reinforcement in asphalt pavements for roads is carried out. In this sense, the study promoted the California Bearing Ratio (CBR) test of recycled aggregate, and subsequently, empirical design was performed using the DNIT method and mechanistic structural evaluation using the MeDiNa AEMC. The results of stresses, strains, and displacements reveal that the material can partially replace the simple granular gravel (BGS) as a sub-base material, contributing positively to the structural performance of the road infrastructure. It should be noted that this is a preliminary study, but the use of the material may be of interest in the short and medium term, significantly contributing to another way of useful and conscious disposal, bringing sustainability to the Construction industry.

SUBSTANTIATION OF THE ROAD CONSTRUCTION UNBOUND MATERIALS CALCULATION MODEL WITH GEOGRIDS STABILIZATION

Summary. Based on the results of experimental studies conducted on different types of flexible pavement structures, the authors of the article examined the behavior of unbound material reinforced with geogrid. A series of static plate load tests were carried out, and the deformation modulus values of traditional and reinforced pavement structures were determined. The impact of the geogrid, installed at the base of the unbound layer of the pavement structure, on its deformation modulus was investigated. It was found that the use of geogrids significantly increases the equivalent deformation modulus of the pavement, depending on the thickness of the inert material layer and the deformation characteristics of the subgrade soil. The effectiveness of the reinforcement depends on the ratio of the deformation characteristics of the pavement and the subgrade soil, as well as the relative depth of the geogrid installation. The greatest effect is achieved on weak soils under large deformations. The results obtained are significant for further research and practical application of pavement reinforcement technology using geosynthetic materials. Keywords: highway, pavement structure, biaxially oriented geogrid, geosynthetic reinforcement, plate load tests, deformation characteristics, loading, reinforcement coefficient, field experiment

Monitoring the performances of a geosynthetic-reinforced pavement during construction

Geosynthetic materials have been widely used to enhance engineering practice in buildings, bridges, and pavements. As a kind of popular stabilization product, geogrid can be used for pavement reinforcement by serving as an additional tensile element. It has been demonstrated by many laboratory studies and numerical simulations that the reinforcement could significantly extend the fatigue life and improve the rutting resistance in flexible pavement. Meanwhile, geotextiles can provide soil separation, filtration and drainage; therefore, mitigating the freeze-thaw disturbances in the subgrade underneath the pavement structure. To study the application of geosynthetics in pavement structures in a more comprehensive aspect, a full-scale study was performed. A fibreglass geogrid which is specifically designed to reinforce the asphalt layer; as well as a geogrid composite material made of bi-axial geogrid bonded to a continuous filament non-woven geotextile, were installed in two field test sections. The geogrid was installed in the middle of the binder course within the asphalt layer, while the geogrid composite was placed at the interface of the base layer and subgrade in another section. The stiffness of the pavement was tested on each layer of the pavement structure during construction. As one of the major criteria to evaluate the pavement condition in North America, the International Roughness Index (IRI) was assessed to investigate the performances of geosynthetic-reinforced pavement during construction on asphalt binder course and surface course.

Geosynthetic Reinforcement: A Strategy for Preventing Deformation of Flexible Pavements on Unstable Ground

This study assesses the effectiveness of geosynthetic reinforcement for flexible pavements on unstable ground. The methodology includes geotechnical data collection and modelling with Alizé LCPC and PLAXIS 2D 8.2. The results highlight the importance of geogrid reinforcement. Vertical deformations are reduced by the geogrids, with values of 3.44. m (phase 0 unreinforced), 2.65. m (phase 1 reinforced) and 2.07. m (phase 2 reinforced with reduced thickness). Horizontal deformations show an improvement of 117.07. % (reinforced pavement) compared with 51.54. % (reduced thickness). Vertical deformations showed a significant reduction, with 141.84. % (reinforced pavement with thickness reduction) compared with 171.32. % (reinforced pavement). In summary, geogrid reinforcement in flexible pavements offers an effective reduction in deformation. Combined with optimisation of the subgrade thickness, this strategy improves stability, strength and bearing capacity. This approach can be extrapolated to other road contexts for a better understanding of its benefits. Keywords: Geogrids, Deformations, Flexible pavements, Unstable soils

Reducing the Highway Networks Energy Bills using Renewable Energy System

Jordan has significant renewable energy potential due to its remarkable geographical location and climate conditions. This potential elevates engaging several innovative renewable alternatives in energy development, which may efficiently minimize the excessive import of traditional energy sources. The objective of this research is to study the potential of utilizing clean and affordable solar energy along roadways such as Jordan’s Desert Highway-15 to be in line with the United Nations Sustainable Development Goals (UN-SDG’s) by installing selected solar panels that possess adequate friction and the ability to allow solar radiation to reach the solar cells, in addition to allowing the load to be bypassed around the cells. The shoulder of the highway, with a length of 315 km and a width of 3.0 meters, has been exploited in order to supply the neighboring areas with energy for those roads, particularly those paved roads, which are poorly lit at night. Furthermore, this study provides direction and guidance concerning the structural performance of non-traditional pavement materials, which are a form of subgrade or pavement reinforcement. The performance of a prototype board on a variety of structural bases has also been evaluated. Overall, this paper found that it is possible to design a solar road panel to withstand traffic loading and that the concrete structural base allows for a significant improvement of the analyzed prototype design, especially in countries with limited energy sources and dependent on imports such as Jordan. Doi: 10.28991/CEJ-2023-09-11-019 Full Text: PDF

State and technical and economic assessment of the road pavement reinforcement method with the bottom-ash mixtures use

The article considers the road pavement reinforcement method with the use of bottom-ash mixtures. In the introductory part, there is an explanation about the conducted experimental works on road pavement strengthening with the cement, bottom-ash mixtures compositions base and stabilising additives (ANT, cryogelite, bitumen emulsion). The monitoring results of the motorway condition (2015–2022), reinforced with bottom-ash mixtures with photo committing changes and technical and economic assessment of the proposed solutions are given. Test section condition monitoring was carried out in accordance with Road industrial methodical document 218.0.000-2003 «Guidelines for assessing the level of maintenance of motorways». Technical and economic assessment is based on the Federal Unit Rates. The comparative options cost with the soil transportation distance of 10 km and cement, bottom-ash mixture, ash, and additives — 100 km in base prices of Federal Unit Rates 2001 has been calculated. Dependences of the road pavement construction cost on the cement transportation method and distance, bottom-ash mixture, ash, and additives transportation at the distance to the soil bank from 4 to 10 km have been constructed. Monitoring results showed that cement-soil road pavement with bottom-ash mixtures can be effectively used as a base for IV technical category motorways, but it is necessary to arrange a layer of pavement for its protection.

PEMBEBANAN MODEL PELAT SKALA KECIL PERKERASAN KAKU (RIGID PAVEMENT) DI ATAS TANAH PASIR

Road infrastructure issues need great attention, considering that this was a link and a cross-economy between one region and another. Damage to the pavement (pavement) would have fatal consequences for the development of an area and an increase in financial needs. Therefore, it was necessary to strengthen a solid road body so that it was able to strengthen the road and be comfortable for traffic loads to pass. Damage to the road body was a major concern in road maintenance efforts. This was due to several very complex problems in terms of the materials used, work implementation, traffic loads passing through the road body, and existing natural conditions. This research studies and analyses the behavior of dynamic-loaded rigid pavements. This load was a traffic load model, and the behavior was reviewed in a small-scale laboratory model. The expected result was to know the model’s behavior with and without rigid pavement reinforcement on both sandy and soft soils, namely in the form of analysis and the ability of the reinforcement to accept traffic loads. This research showed that the plate test model shows that multiple plate thickness supports plate stiffness. The cakar reinforcement plate affected the stiffness of the plate. The deflection value due to loading on the 3-layer plates (6.3 mm thick) was comparable to the 1-layer plate (2.1 mm) with cakar. FEM analysis can be performed to predict deflection due to loading in the center of the plate, and this value was very close to the results of the laboratory small-scale loading test. The CBR value used to calculate the deflection was closest to the real condition, namely the value before loading 0.2 kN and after loading 0.8 kN.

Evaluating long-term benefits of geosynthetics in flexible pavements built over weak subgrades by finite element and Mechanistic-Empirical analyses

Finite element (FE) models were developed to evaluate the benefits of geosynthetic reinforcement in flexible pavements built over weak subgrades. The parametric study was conducted to evaluate the effect of different variables such as base thickness, geosynthetic type, geosynthetic stiffness, and double-geogrid layers. FE analyses were performed for 100 load cycles, and the permanent deformation (PD) was used to calibrate the empirical parameters in MEPDG equations for each layer, which were used to extrapolate PD data for the service life of pavements. The PD curves for unreinforced and similar reinforced sections were used to evaluate the Traffic Benefit Ratios (TBR) at different rut depths. The results showed that the inclusion of one geogrid/geotextile layer at the base-subgrade interface could significantly reduce pavement rutting. The use of geogrid is more effective than geotextile in reducing pavement rutting. The derived TBR values range from 1.91 to 8.9 for one geogrid layer and from 1.71 to 5.92 for one geotextile layer. The TBR values increase with increasing the rutting depth and geosynthetic stiffness. The TBR value demonstrates an optimum at a base thickness of 10 in. The results demonstrated the superior benefits of using double geogrid layers compared to single-layer cases.

Experimental Study of Strength Development in Black Cotton Soil and Granular Material Reinforced with Geogrid and Non-Woven Geotextile

Reinforcement of flexible pavements using geosynthetics is gaining widespread application. However, there is inadequate understanding of strength development for non-woven geotextile and geogrid as reinforcement in Black Cotton Soil (BCS) and granular material in relation to cement stabilization method. Therefore, this paper presents experimental study to investigate strength development for BCS and granular material reinforced with geogrid and non-woven geotextile using California Bearing Ratio approach. The categories of samples tested were; neat, reinforced and cement stabilized. All samples were tested after 4 days’ soak. Placement of reinforcement material in BCS was done at 0.3H and 0.6H for single layer reinforcement while for double layer reinforcement, it was done at both 0.3H and 0.6H. In granular soil, single layer reinforcement condition only was considered at 0.2H, 0.4H and 0.6H. Cement stabilization for both BCS and granular soil was done by the following percentages of cement increment; 1%, 2%, 3% and 4%. From the study, the strength improvement considering single layer reinforcement by geogrid and non-woven geotextile in BCS was 37.5% and 45% respectively. In granular material, CBR strength increased by 21% and 14% due to geogrid and non-woven geotextile respectively. Percentage increase in CBR of reinforced BCS corresponded to that of over >1% cement stabilization. To further enhance decision making between these strength development alternatives, it is recommended to advance it to cost analysis.

Basalt fibre continuous reinforcement composite pavement reinforcement design based on finite element model

Abstract The thrust of basalt fibre (BFRP) tendons will result in narrower transverse crack spacing, decreased load transfer capacity of transverse cracks and voids at the bottom of the slab, which will lead to thrust failure. The thesis uses the finite element analysis method to analyse the material characteristics of BFRP tendons. At the same time, the article determines the critical load position corresponding to the tensile stress of concrete and BFRP tendons, and analyses the influence of voids, crack spacing and other factors on the load stress of concrete and BFRP tendons. The study results found that continuously reinforced concrete and asphalt overlay composite design can reduce cracks.

Basalt fibre continuous reinforcement composite pavement reinforcement design based on finite element model

Abstract The thrust of basalt fibre (BFRP) tendons will result in narrower transverse crack spacing, decreased load transfer capacity of transverse cracks and voids at the bottom of the slab, which will lead to thrust failure. The thesis uses the finite element analysis method to analyse the material characteristics of BFRP tendons. At the same time, the article determines the critical load position corresponding to the tensile stress of concrete and BFRP tendons, and analyses the influence of voids, crack spacing and other factors on the load stress of concrete and BFRP tendons. The study results found that continuously reinforced concrete and asphalt overlay composite design can reduce cracks.

Structure formation of dispersion hardened organomineral mixtures

The relevance of the work is determined by the need to improve the properties of the road pavement layers. Under conditions of increasing carrying capacity of vehicles and traffic intensity, pavements designed and constructed in accordance with the regulatory documents are destroyed without reaching the required service life. The pavement reinforcement with chemical fibers is one of the ways to solve this problem. The aim of this work is to study the structure formation of dispersion reinforcement of the pavement layers made of organomineral mixtures. Theoretical calculations are presented for the structural formation with directional reinforcement by using meshes and interlayers with dispersed reinforcement. It is shown that directional reinforcement of the structural layers provides compensation of tensile stresses only at the bottom layer, where the mesh locates. At the edges of the deflection bowl in the upper layer, tensile stresses are not compensated because the reinforcing mesh locates at the bottom layer. With dispersed reinforcement, chemical fiber penetrates in the structural layer, including its top and perceive tensile loads and reduce the likelihood of cracking. The implementation of the liquidphase method of dispersed reinforcement of organomineral mixtures improves the bitumen adhesion to the fiber surface of the dispersed reinforcement.

Influence of Geocomposite Properties on the Crack Propagation and Interlayer Bonding of Asphalt Pavements.

The application of geocomposites as reinforcement in asphalt pavements is a promising solution for the maintenance/rehabilitation of existing pavements and for the construction of new pavements, whose effectiveness strongly depends on the physical and mechanical properties of the geocomposite. This study aims at assessing the influence of four different geocomposites, obtained by combining a reinforcing geosynthetic with a bituminous membrane, on the crack propagation and interlayer bonding of asphalt pavements. First, a laboratory investigation was carried out on double-layered asphalt specimens. The crack propagation resistance under static and dynamic loads was investigated through three-point bending tests (carried out on specimens with and without notch) and reflective cracking tests respectively, whereas the interlayer shear strength was evaluated through Leutner tests. Then, a trial section was constructed along an Italian motorway and a Falling Weight Deflectometer (FWD) testing campaign was carried out. The laboratory investigation highlighted that—as compared to the unreinforced system—the geocomposites increased the crack propagation energy in the layer above the reinforcement from five to ten times, indicating that they can significantly extend the service life of the pavement by delaying bottom-up and reflective cracking. However, they also worsened the interlayer bonding between the asphalt layers (de-bonding effect). The field investigation indicated that all geocomposites decreased the stiffness of the asphalt layers with respect to the unreinforced pavement as a consequence of the de-bonding effect, thus corroborating the laboratory results. Based on the results obtained, it is desirable that the geocomposite possess a high energy dissipation capability and an upper coating ensuring good adhesion between the asphalt layers. The monitoring of the existing trial section in the future will provide useful data on the long-term field performance of reinforced pavements subjected to actual motorway traffic.

Bituminous Pavement Reinforcement with Fiber: A Review

This paper attempts to display, analyze and discuss the literature affiliated to the previous research data on road surfacing in pavement engineering reinforcement. In this paper, a review of the background and present status of road surfacing is also provided for supportive explanation of the significance of fiber-reinforced asphalt pavement HMA and its role in providing effective and durable surfacing for heavy-trafficked roads. The paper attempts to clarify some of the terms and notions related to the discussions to give the readers the needed background, to be able to actively understand the experiments and discussions. Results from many studies confirm that fiber specifically enhances the optimum bitumen content in the design of the mixture and halts the bitumen leakage due to its asphalt absorbing susceptibility. Fiber modifies the visco-elastic response, susceptibility against moisture, increase resistance to rutting, as well as lowers the pavement fatigue cracking.

REHABILITACIÓN DEL FIRME DE CUATRO GLORIETAS MEDIANTE UN REFUERZO DELGADO DE HORMIGÓN (“THIN WHITETOPPING”)

This article describes the design and construction of the structural rehabilitation of the bituminous pavement of four roundabouts by means of the arrangement of a 12 cm layer of vibrated concrete with fibres with very close joints (technique known as "thin whitetopping"). The roundabouts, which belong to the N-II National Road as it passes through La Jonquera (Spain), are subject to high levels of heavy vehicle traffic (IMDp > 4,000 heavy vehicles/day). In the project phase, the causes of deterioration of the original road surface were studied, its remaining bearing capacity was characterised and the thickness of concrete to be used was calculated. In the most damaged areas, the bituminous mixture was completely replaced by a lower quality concrete which was adhered to the concrete of the reinforcement by means of metal connectors. In addition, a detailed design of the transitions between the rehabilitated and the existing pavement and the arrangement of the joints was also carried out. Throughout the document, the different tasks carried out for the design and construction of the adopted solution are described in detail and, finally, design and construction recommendations are provided based on the results obtained. Keywords: Concrete, concrete bonding, Concrete with fibres, Reinforcement of pavements with concrete, Fuel resistance, Whitetopping.

Study on the micro-mechanism and structure of unsaturated polyester resin modified concrete for bridge deck pavement

To solve the problems of durability reduction and service-life shortening of bridge deck pavement concrete, this study investigated the effect of unsaturated polyester resin (UPR) as a modifier on the cement hydration and the microstructure morphology of pore, crack and interface transition zone (ITZ) of cement concrete. The enhancement mechanism of UPR incorporation into bridge deck pavement concrete was determined with the aid of meso- and micro-structure analysis technology and digital image processing approach. The results indicated that the incorporation of UPR-emulsion might have a significant retarding effect on the cement hydration process while greatly enhanced the compactness and anti-permeability of the concrete. In addition, the addition of UPR emulsion could effectively delay crack initiation and restrain the propagation of crack during consolidation process, and reduce the zone area and materialize intense densification and homogenization in terms of ITZ. In comprehensive consideration of the characteristics of pore structure and micro-crack, the introduction of 3% UPR-emulsion could be recommended to achieve the performance reinforcement of deck pavement concrete to a certain degree.

Development of a rational design procedure based on fatigue characterisation and environmental evaluations of asphalt pavement reinforced with glass fibre grid

ABSTRACT The work presented in this paper is part of an interdisciplinary research project named SolDuGri dealing with the reinforcement of asphalt concrete pavements using glass fibre grids. We present in this paper one of the main results of the project dealing with the development of a rational design procedure for reinforced pavements. Laboratory and full-scale accelerated fatigue tests were carried out to define a relationship between the fatigue resistance of reinforced and non-reinforced samples in function of the position of the grid, and to calibrate a fatigue design criterion. Design examples using the proposed design procedure show that the reinforcement of pavements leads to a reduction of the asphalt thicknesses, compared to the unreinforced solution. Furthermore, environmental impacts including life cycle assessment, particles emissions and recycling of the reinforced pavement solutions obtained from the design and experimental works are investigated. These environmental studies are new in this research topic.

Experimental investigation on the flexural and post-cracking behaviour of geogrid-reinforced concrete overlays

Innovative materials are on the rise as alternatives to steel reinforcement in concrete structures. Recently, the use of polymeric geogrids as reinforcement elements has expanded into Portland cement concrete (PCC) overlays rehabilitation. Research conducted to date has indicated that the use of geogrids as reinforcement in concrete pavements shows both post cracking ductility and superior load capacity. Although this topic is not so explored in the literature, the use of geogrids in thin concrete overlays, pathway, pedestrian sidewalks and floating slabs is promising and gives a new employment area for the use of geogrid reinforcements. This paper presents an experimental investigation on the flexural behaviour, post-cracking and fracture energy performance of geogrid-reinforced concrete beams under four-point bending test. Different geogrids were embedded at one-third depth (from bottom) of concrete beam specimens (500 × 150 × 150 mm). The PCC mix was prepared using Ordinary Portland Cement (OPC grade 53) with compressive strength of 40 MPa. Results confirmed that the flexural performance and post-cracking resistance of the concrete beam specimens could be enhanced by the presence of geogrids, as evidenced by load-deflection response, crack mouth opening displacements and change in failure mode. Triaxial geogrids showed 11% increase in flexural strength of concrete beam, highlighting the potential benefits of geogrids reinforcements in PCC overlays.

Sensitivity Analysis of Determining the Material Parameters of an Asphalt Pavement to Measurement Errors in Backcalculations

Nondestructive tests of road pavements are among the most widely used methods of pavement condition diagnostics. Deflections of road pavement under a known load are most commonly measured in such tests, e.g., with the use of falling weight deflectometer (FWD). Measured values allow to determine the material parameters of the road structure, corresponding to the obtained results, by means of backcalculations. Among the factors that impact on the quality of results is the accuracy of deflection measurement. Deflection basins with small differences of displacement values may correspond to significantly different combinations of material parameters. Taking advantage of them for mechanistic calculations of road pavement may eventually lead to incorrect estimation of the remaining fatigue life and then inadequate selection of pavement reinforcement. This study investigated the impact of measurement errors on the change of the obtained values of stiffness moduli of flexible road pavement layers. Additionally, the influence of obtained material parameters on the values of key pavement strain, and consequently on its design fatigue life was presented.