Research team

Energy and Materials in Infrastructure and Buildings (EMIB)

Expertise

Expertise in bitumen rheology, asphalt recycling and innovative technologies for sustainable asphalt pavements, structural pavement design inclusive.

Sustainability assessment of roads containing reclaimed asphalt pavement - Decision support based on life cycle assessment & life cycle cost analysis during road design. 01/11/2020 - 31/10/2022

Abstract

Recycling reclaimed asphalt pavement (RAP) in new roads ensures a circular approach and increases the sustainability. In general, there are three applications for RAP: asphalt mixtures, cement bound base layer mix and unbound material. However, the selection process for any application is currently not optimized. Recent laboratory research also shows that the addition of RAP in new structures does not negatively affect the mechanical properties if the mixture and/or the structural design is optimized. However, it is important to note that these optimizations can have a major impact on the economic and environmental impact of our roads. Therefore, it is important to assess these effects at an early stage so that the most sustainable solution can be chosen. This research will implement life cycle assessment (LCA) and life cycle cost analysis (LCCA) in road design to analyse the environmental and economic impact of the use of RAP in new roads. The first part will focus on the recycling potential of RAP. It will optimize the recycling process and determines the salvage value of RAP as a resource. Next, RAP will be used in a new cycle and the impact on the whole life cycle of roads will be examined. Finally, the LCA and LCCA will be combined and an optimization process will be designed which can be implemented in road design so the most sustainable material flow for RAP can be determined.

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Sustainable foundations through in situ recycling with foamed bitumen technology (FOAM) 01/11/2020 - 30/10/2022

Abstract

In Flanders, more and more attention is being paid to sustainable road structures. For the time being, attention is often focused on the pavements. However, over the next few decades, foundations and sub-foundations of existing roads will also have to be renewed. Only this will enable us to maintain our road infrastructure, which is of primary economic and social importance, for future generations. Abroad, we are seeing more and more innovative use of materials for foundations: new material forms (e.g. geopolymers) and production technologies (e.g. emulsions, foamed bitumen). This project uses one of the most promising innovative technologies: in situ recycling of asphalt pavements into bonded foundations. With this technology, the existing asphalt will be milled either completely or partly, possibly with part of the foundation, and mixed on site with foamed bitumen and a hydraulic binder. This mixture is then compacted into a new foundation layer. In addition, two alternative binding agents are included in a comparative laboratory study: geopolymer to replace cement and emulsions to replace the foamed bitumen. Both materials are currently being researched by UAntwerpen for their applicability in foundations, in collaboration with Odisee University College. Foam technology has existed abroad for more than twenty years, but is not gaining a firm foothold on Flemish soil because of the high investment, numerous unknown factors for material selection and profitability, limited know-how and lack of real product descriptions. As a result, the potential of in situ recycling of existing foundations is severely underused. Furthermore, about 40% of the released asphalt granulate (600.000 tons) is currently used as unbound granulaes as embankment, or in bonded state with cement, while in combination with the foamed bitumen the precious bitumen of the asphalt granulate is still used, which would probably be preferable for an LCA and LCC. In view of the fact that foundations are often laid for public works, the sector considers it necessary to test this innovative step for Flemish road construction via a Tetra project.

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CRUMBit Phase 2. 01/09/2020 - 31/08/2023

Abstract

The main aim of this research is to identify the barriers preventing the use of recycled tire rubber in Belgian asphalt road surfaces and to develop market-ready solutions that can be presented to road authorities. The main expected results within the second phase of this project are the following: scaling up of the rubber modified bitumen to asphalt applications, leaching tests, analysis of the recyclability and an LCA/LCC study of rubber modified asphalt. The final work package includes the necessary follow-up steps to install the final product in one or more test tracks and finally get it approved for the Belgian market.

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Durability assessment of the complex bonding mechanism between alkali activated materials and reclaimed asphalt aggregates 15/07/2020 - 14/07/2021

Abstract

CEFET-MG (Brazil) and UAntwerpen started a joint Phd in order to investigate the use of geopolymers and Reclaimed Asphalt Pavement aggregates (RAP) as an alternative for cement-treated base material for road.The main objective of this PhD research is to determine whether a concrete produced with "Alkali Activated" binder and RAP aggregates as replacement for natural aggregates, can yield a material (RAP-AAM) with acceptable strength, durability and low environmental impact to be used as subbase/base layers of pavements. The project contains an extensive experimental test program in order to validate several geopolymers and the binding with RAP. Confocal Laser Scanning Microscopy is used to evaluate the bonding area on mortars and Digital Image Correlation will reveal the effect of bending mechanism on the mixtures. An LCA will calculate the environmental impact of geopolymers as an alternative for cement.

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High-end electron paramagnetic resonance instrumentation for catalysis and materials characterization. 01/05/2020 - 30/04/2024

Abstract

Electron paramagnetic resonance (EPR) offers a unique tool for the characterization of paramagnetic systems found in biological and synthetic materials. It is used in very diverse fields, such as biology, chemistry, physics, medicine and materials sciences. EPR is a global name for many different techniques, of which the pulsed EPR spectroscopies are the most versatile ones, able to reveal very detailed structural information. The University of Antwerp hosts a pulsed and high-field EPR facility that is unique in Belgium. However, the basic continuous-wave EPR instrumentation that underlies this facility needs urgent upgrade. Moreover in recent years, the technical realization of arbitrary waveform generators (AWGs) with clock rates higher than a gigahertz has initiated a new era in EPR spectroscopy. These AWGs allow for novel experiments with shaped pulses through which more detailed information about the systems under study can be obtained. Use of these shaped pulses avails enormously increased sensitivity and spectral width. This is particularly important for the study of nanostructured materials and the detection of transiently formed active sites during catalysis, device operation or biological in-cell reactions, topics of major interest for the consortium. The requested extension of the EPR facility is essential to assure that EPR at UAntwerp remains at the forefront in this rapidly changing field.

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Photocatalytic Asphalt Pavements for the Port of Antwerp (PAPPoA): a feasibility study (Port of the future). 01/03/2020 - 30/12/2021

Abstract

Asphalt pavements need to be able to withstand the effects of weather (i.e. UV, rain, and freeze-thaw cycles) and (heavy) traffic loading during their service life, while maintaining the necessary mechanical performance, e.g. limited rutting, fatigue resistance and water resistance, and providing comfortable and safe driving conditions in terms of the surface properties, taking into account mostly skid resistance and texture. Recently, not only investigations related to the mechanical performance or overall environmental impact of asphalt pavements are conducted, but more attention is given towards smart pavements, e.g. photocatalytic pavements. In most cases, TiO2 nanoparticles (semiconductor material) are used in the field of photocatalysis for many purposes, mostly for air and water-pollutant photocatalytic degradation, as it is effective, non-toxic, easily available and cheap. Due to the huge surface area of road pavements and its vicinity to the exhaust gases from automobiles, the photocatalytic capability is quoted as promising for air-cleaning. TiO2 is able to react under UV-light (only 3-5% of the sunlight spectrum) with pollutant gases, such as NOx and SO2, creating water-soluble nitrates and sulfates respectively, which are easily removed from the asphalt pavement by rain. It also has the potential to degrade soot, (spilled) oil and volatile organic compounds (VOC). In this project, we want i) to further investigate further the effects of traffic on the photocatalytic efficiency, ii) to determine possible effects on traffic safety (skid resistance) and iii) to develop an in-situ test setup to measure the NOx reduction.

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Purchase of a gyratory compactor for asphalt samples. 01/01/2020 - 31/12/2021

Abstract

As both present gyratory compactors are at the end of their lifespan (purchase in 2000 and 2008), with numerous calibration issues and temporary failure, a new gyratory compactor for research purposes is budgetted on this project. This device is essential as a first step in asphalt research as many standardized test methods, such as fatigue and water sensitivity, have to use specimens compacted according to EN 12697-31. With this device, cylindrical asphalt test pieces with a diameter of 100 or 150 mm are compacted, including the real-time monitoring and measurement of important research parameters such as the percentage of air voids and the shear stress. In addition, the height and apparent volumetric mass of the specimen can be checked and displayed. All necessary accessories such as molds for both standard and warm mix asphalt mixtures are included in this project proposal.

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AQ²UABIT – Advanced Qualitative and QUantitative surface Analysis of BITuminous binders using laser scanning confocal microscopy. 01/01/2020 - 31/12/2021

Abstract

In this project, an innovative methodology is developed by using Laser Scanning Confocal Microscope (LSCM) to investigate the behaviour of bituminous binders and mortar under specific physical and mechanical conditions including the impact of several additives. Bitumen, an oil derivate, is an important binder used in asphalt mixtures, roofing materials and emulsions. Regarding the circular economy, a higher recycling rate and increased service life is expected for future application, as it provides both economic and ecological benefits: a base layer with 40% reclaimed asphalt is about 25% cheaper and its total environmental impact is reduced by 6% (based on an LCA-study). An increased service life and quality avoids mobility problems, damage, fast deterioration etc. In most cases, both aspects are proven by mechanical tests in laboratory. However, efficient use of this material demands more and more scientific insight in the fundamental structural behaviour of bitumen. In order to enhance the current sustainability vision of 'closing loops', besides the mechanical properties, also the physico-chemical aspects must be taken into account, especially for higher recycling rates, fibre reinforcement, and additives improving healing and fatigue resistance. Moreover, both the development of innovative technologies, such as smart fibres in bitumen, and understanding the behaviour of the bituminous mixture, e.g. the ageing mechanism, need validated physico-chemical models. In this project, both methodologies, mechanical and physico-chemical aspects, are used to investigate the properties of the same bituminous samples (bitumen and mortar). A new technology is introduced and validated: the latest Laser Scanning Confocal Microscope (LSCM) allows for measurements across a 50 mm area with nanometre resolution (5 nm in Z-direction and 10 nm in the XY-direction). This technology allows to scan quickly (5 s measurement time) the bitumen surface in order to visualize aspects like bee structures (wax content) and bitumen coverage (adhesion between binder and granulate). Furthermore, the surface profile and film thicknesses are measured as well, which is important in the analysis of bitumen blending. Lastly, by combining these qualitative images with the Digital Image Correlation (DIC) methodology, it will be possible to obtain detailed quantitative results and to track changes in the bituminous mixture on a nanometre scale, e.g. during blending or healing. This technology will be used, together with mechanical tests (Dynamic Shear Rheometer, Direct tensile tests, Fraass bending point) to investigate the ageing/healing process, blending of old and new bitumen during recycling, and optimized use of additives, such as fibres, crumb rubber and rejuvenators. The project is divided into three steps: - integration of this new high-tech equipment, especially adjusted for bitumen research, in our bitumen laboratory, including Matlab software for data analysis; - development of a methodology for testing bituminous samples using an LSCM to fully understand bitumen morphology and physico-chemical mechanisms, related to ageing/healing, improved use of additives and as verification for mechanical tests. An opensource database of 6 binders, containing the physico-chemical and rheological properties, will be available and a secured database with the special binders will be available for collaborative research. - valorisation trajectories for designing new materials in a bituminous matrix, such as smart fibres or enhanced crumb rubber modified bitumen.

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Automated inspection of infrastructure using drones (AutoDrone) 01/10/2019 - 30/09/2021

Abstract

In this project we will use drones to detect and monitor damage in infrastructure: wind turbines, bridges, buildings, solar panels, pavements, etc. Firstly, an overview of available path planning tools will be given. Secondly, we will develop machine learning tools to automatically detect damage (cracks, potholes, corrosion). The third aim of the project is the development of a methodology to allow a systematic comparison of repeated drone based camera measurements. During the project 9 case studies will be performed. The project is performed by UAntwerpen and WTCB together with a large consortium of companies active in drone based inspections or owners of infrastructure.

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Crumb rubber modified bitumen (CRUMBit). 27/05/2019 - 30/06/2020

Abstract

The main purpose of this research is to identify the barriers which inhibit currently the use of tyre-derived crumb rubber in Belgian asphalt roads and to develop different market-ready solutions that can be introduced to the road authorities. The main expected results for phase I of this research are the following: detection of possible toxicity and health issues when using crumb rubber as bitumen modification (e.g. measurement of the volatile organic compounds or VOCs) and comparison of the mechanical and rheological properties of crumb rubber modified bitumen (CRmB) with commercial polymer modified bitumen (PmB).

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Sustainable asphalt by using rejuvenators (REJUVEBIT) 01/11/2018 - 31/10/2020

Abstract

Reclaimed asphalt is usually reintroduced into the asphalt production cycle as asphalt granulate, mainly in base courses. With an average reuse ratio of 66% for asphalt granulate, there is still a final step to be taken to optimise reuse and/or broaden the scope of application, for example use in top layers. Rejuvebit aims to technically, economically and ecologically evaluate the use of rejuvenation agents in the asphalt sector, so that their innovative use can lead to an increase in the recycling percentage of released asphalt granulate. The review and market survey of the supply of rejuvenation agents leads to a ranking of potential rejuvenation agents for the Flemish asphalt sector. On the basis of 6 demonstrative trial sites in Flanders, the technical impact of the use of rejuvenation agents was evaluated at the level of mixture design pre-study, mechanical properties of the post-study and traceability. These demonstrations were intensively documented by means of a written final report and a publicly accessible website. Each test section was divided into subsections so that, in addition to a reference, variants were also constructed. The project provides for the reporting of the quantification of the environmental impact and economic feasibility for Flanders, with scenarios for asphalt plants, processability and life span, in relation to a reference, in order to increase the recycling rate at sector level and per type of mixture. The project results were communicated through reports, the project website (https://www.uantwerpen.be/en/research-groups/emib/rejuvebit/) and various presentations. The project deals with sustainability in the sense of technical durability (quality and life span) and sustainability (financial feasibility, ecological profile and social impact). The economic impact refers to a higher production of asphalt and more in-depth innovation studies for "greener asphalt", since the increase in recycling (both higher percentages and new applications) will not lead to lower turnover but to higher production for the same budget of the client. In this project, the direct economic effect (for the target group) is calculated for the 6 test surfaces (cost price balance with higher recycling and extension of service life). The social added value is to be found in a better preservation of the road infrastructure (demonstrated in this project by means of lab test results and afterwards by having test surfaces available) and a lower ecological footprint with a higher production quantity, demonstrated in this project by means of comparative LCA-studies of the 6 test surfaces. This quantification can subsequently be used by policy makers for further environmental measures in this sector, or as an example in other sectors. The project was successfully completed. The project has shown that the use of asphalt granulate in top layers is possible up to 40% and in baselayers up to 80%, provided that a rejuvenating agent is used. The test sites are monitored annually for further evaluation. More info via: https://www.uantwerpen.be/en/research-groups/emib/rejuvebit/

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Development of a novel optical signal processing method for analyzing data of the deformations of the asphalt construction by using Fiber Bragg technology in order to design new asphalt model. 01/07/2018 - 31/12/2019

Abstract

This project focuses on collecting and verifying reliable deformation data of asphalt pavements by using Fiber Bragg Grating sensors. These sensors are already integrated in a bicycle path at the University of Antwerp (project CyPaTs at Campus Groenenborger). FBG is a new technology for measuring deformations in a material, e.g. by external loading. In asphalt pavement, the service life of the lower positioned asphalt layers is directly related to these deformations, loadings and rest periods between loadings. Nowadays, this service life is monitored by Falling Weight Deflection (FWD) measurements only for primary road network and each two years. These measurements are time-consuming, expensive and the road needs to be closed for a certain time. The FBG technology could give a solution to measure these deformations continuously for a lower cost. Moreover, FBG will give more insight in the deformation under all available conditions (temperature of the road, different loadings, rest periods). In order to predict service life, an asphalt response model needs to be developed, based on a monitoring program over at least 1 year. The project will allow to determine long-term ageing and healing properties of the pavement. In this project both technology domains will be used: FBG data will give the deformations in the structure in such a way that the parameters of a visco-elastic plastic asphalt model are optimized continuously. The installed FBG monitoring system of CyPats will be used in this project. Data will be gathered by means of a monitoring campaign in normal conditions (climate) and forced-conditioned on site; calibrated loadings and rest periods. These data will be used for fitting the parameters of a simple response model by Young modulus. The data can be used in future work for parametric fit in more complex models, e.g. a visco-elastic (Burgers) and a visco-elastic plastic model (Huet-Sayegh). A first step will be taken in this project. A challenge to be encountered is to distinguish the effect of ageing and healing, e.g. increase of resistance to deformation during a rest period after a loading set. In current models these are not taken into account and the expected service life has to be estimated by doing FWD tests with a lot of variance in results. Moreover, in the FBG setting, the ageing is monitored continuously. This will give insight in the ageing mechanism in time of asphalt pavements allowing to use this factor as fundamental knowledge. The ageing factor will be used in a complex response model and in a prediction model for estimated service life. Moreover in the future, with this knowledge, a new ageing method under laboratory conditions can be developed based on the measurements on site. The project work program consists of 3 workpackages. The first workpackage focuses on the signal processing of optical FBG spectra i.e. how to determine the peak shifts in order to obtain a correct strain value. workpackage 2 focuses on the identification of the Young modulus from FBG vibration measurements using the so-called inverse modelling approach to identify the mechanical material properties of the different layers of the asphalt, starting from a simple elastic Young's modulus model. Workpackage 3 deals with the monitoring of the Young modulus in time on the asphalt pavement structure of CyPaTs bicycle path during 24 months, and relating these to more complex models.

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Study into OSA asphalt mixtures and cores. 25/03/2017 - 31/07/2017

Abstract

In this study the cause of damage to drilled OSA cores is researched. The study includes visual examination, queries related to the damage, analysis of previous research. Objective: cause of damage, conclusions and possible recommendations for follow-up and new tests.

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ROAD_IT: Towards an efficient process management system for asphalt road construction works by IT. 01/12/2015 - 30/11/2017

Abstract

The objective of this project is to develop and implement a robust IT architecture with a digital portal. This system allows the communication between all active parties of the asphalt sector during a construction work and stores data for later interventions. The architecture allows in each step and for each partner and device to communicate in real time in order to achieve an effective process. The project includes four demonstration cases.

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Development of a fibre mixture for durable asphalt mixtures 01/10/2015 - 31/03/2017

Abstract

In this project, a study is performed in order to compose and design an optimal mix of fibers. The project team consists of UA-members in cooperation with an industrial partner. This fiber mix will lead to a more durable asphalt mixture for top layers, as an alternative to polymer bitumen. The test program includes: selection of the fiber, optimizing the fiber blend, experimental testing with i.a. wheel rutting tests and ravelling tests, research in the bituminous mortar and an analysis related to recycling of fibre-reinforced asphalt mixtures.

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Preliminary study into the economic and technical feasibillty of the use of river sludge in bitumen bound materials 07/10/2014 - 28/02/2016

Abstract

This project represents a formal research agreement between UA and on the other hand the Flemish Public Service. UA provides the Flemish Public Service research results mentioned in the title of the project under the conditions as stipulated in this contract.

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Pilot project Quiet Road Surfaces: technical guidance and implementation monitoring program. 01/09/2014 - 31/12/2017

Abstract

This project represents a formal research agreement between UA and on the other hand City of Antwerp. UA provides City of Antwerp research results mentioned in the title of the project under the conditions as stipulated in this contract.

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