Research Johan Blom

Abstract

The harmful effects of the building industry on our environment pose an increasing pressure on the development of new sustainable practices of construction. This project aims at laying the scientific foundation of basic design strategies to develop longer-lasting and more adaptable load-bearing structures of buildings, which are considered the most permanent building part and which hold the vast majority of embodied carbon. However, to design for change, change must first be understood. Through the empirical analysis of existing rehabilitated buildings, this project will generate novel insight into how and under which constraints buildings can indeed change, connecting findings from academic research and architectural practice.

Researcher(s)

• Promoter: Rinke Mario
• Co-promoter: Blom Johan
• Fellow: Pacquée Robbe

Research team(s)

• Henry van de Velde

Project type(s)

• Research Project

Abstract

Mobility is one of the essential prerequisites for the sustainable growth of modern human society, which is increasingly facing climate change, urbanisation, and raw materials depletion. To answer these challenges, substantial progress in the fundamental knowledge on microstructural and physicochemical properties of bitumen, as a critical material component of asphalt pavements, and the innovative approaches to its enhancement is the underlying factor for the breakthrough of road infrastructure in a zero-emission future. The behaviour of bitumen and its interaction with mineral aggregate is projected throughout all length scales of asphalt performance. Therefore, a deep understanding of its intrinsic features and the interaction with other material phases of asphalt is essential for successfully fulfilling the above goal. During recent years, there has been extensive multidisciplinary research all over the world dedicated to identifying the relations between the microstructural evolution of bitumen (primarily in the context of photo-oxidative ageing) and its rheomechanical performance, which directly affects the durability of asphalt pavement layers. Although these developments were made possible by an enormous advancement in various microscopic techniques, a systematic quantitative spatiotemporal characterisation of its multiphase composition considering various modifiers and comprehensive outside effects is still unavailable. The global aim of this scientific research network (SRN) is to conduct comprehensive basic research on the spatiotemporal microscopic and spectroscopic features of bitumen responsible for numerous physico-chemo-mechanical processes in the interaction between internal and external material phases. The planned research will be conducted by applying innovative ways for simulating thermal, oxidative, and mechanical effects (including their combination) to quantify the real-time kinetics of the material's microstructure and interphase relations. This SRN will join and implement cutting-edge experimental resources and techniques in the field. It will primarily consider bitumens of various origins (from around Europe), emerging aspects of elastomeric polymer modification, and rejuvenation of aged (i.e. recycled) bitumen. The currently highly relevant phenomena like phase separation, polymer degradation, and interaction with fine mineral aggregate will also be investigated. The main methods for pursuing these objectives will be laser scanning confocal, atomic force, scanning electron microscopy, and different types of calorimetry, thermogravimetric analysis, and crystallography. The data processing will also include advanced image analysis algorithms as a new approach in the field of bituminous materials. This network will comprise leading and well-established scientists and stimulate the contribution of members below the postdoctoral level. Besides providing new and deep materials science-based insights, the output of this SRN should include the establishment of original approaches and new standards in the microstructural characterisation of bitumen as a multiphase system. These outputs would represent an essential background for further advancement of bitumen-based pavement materials and their implementation in sustainable road infrastructure systems.

Researcher(s)

• Promoter: Blom Johan

Research team(s)

• Sustainable Pavements and Asphalt Research (SuPAR)

Project type(s)

• Research Project

Abstract

This research project aims to understand how buildings change over their lifetime if they are adapted. If buildings are not or cannot be used anymore, their very characteristic design, particularly its building structure, often prevents it from being adapted to new possible functions leading to vacancy and, consequently, demolition. Obsolescence is by far the main reason for demolition — and mostly of rather young buildings: Their service life (ca. 40 years) is thus much shorter than its physical life expectancy (min 80-100 years). Understanding the circumstances of change, first of its use and then of the building, and which components prevent or allow necessary transformations or extensions, forms a substantial basis for the design of new buildings. Such knowledge of change is largely missing. Building both on a detailed analysis of various case studies along their adaptations and the agency of stakeholders in the building industry, the project will model adaptability empirically to show how building functions, construction systems and materials are connected, and which paths of sustainable building design are most likely to produce long-living buildings.

Researcher(s)

• Promoter: Rinke Mario
• Co-promoter: Blom Johan
• Fellow: Pacquée Robbe

Research team(s)

• Henry van de Velde

Project type(s)

• Research Project

Abstract

Both international research and research at UAntwerpen (AIRbezen/strawbAIRies/CurieuzeNeuzen) have shown that our outdoor air quality, especially in urban areas, often leaves much to be desired. We breathe this unfiltered air every day, not only outside but often also inside our buildings. As traffic is a major source of this problem, it is not surprising that increased concentrations of pollutants and harmful particulate matter are measured along roads. In addition to the use of new means of transport, efficient local capture and purification, close to the road, can therefore offer a solution to control the situation and prevent further spread. At TU Eindhoven, a study was recently carried out in which the concentration of fine particulate matter in the outside air was removed by means of fine dust extractors. In Belgium, an innovative "Clean Air" concept was developed by BESIX for active purification of outdoor air using moss filters. Although the operation and potential of both technologies has been demonstrated, there are no practical implementations other than pilot plants, because the investment is not yet attractive. Stakeholders indicate that it is necessary to demonstrate the socio-economic benefits to convince them. This PoC project wants to contribute to tilting the balance between system costs for installation and maintenance on the one hand and filter efficiency versus the social costs of pollution on the other hand in a positive direction for the Clean Air system. The focus is on research into the development of cheaper, more efficient and fully renewable moss filters. It will be investigated whether surplus and exhausted moss from the wall can be reused and processed into an innovative zero-waste, bio-based basic filter cloth. The objective is to further close the current system by reusing waste flows as raw materials. Due to the limited project budget within this PoC project, we will initially focus on the development and characterisation of nonwoven 2D textile composites based on recycled moss fibres. We will also actively look for additional funding to investigate the possibilities of nonwoven 3D multilayers. As support, BESIX will install a fully operational airpurifying moss wall on the BlueApp site, in order to determine and compare the in-situ filter efficiency of the new moss filters under equal (multiple filters can be placed in the wall next to each other) but variable boundary conditions (wind direction, wind speed, sunlight, etc.). This project proposal focuses on research into the development, production, testing and optimisation of a more efficient, cheaper and circular Clean Air heart. The moss filters have to be affordable, work optimally and subscribe to a circular economy before other adaptations are meaningful. However, the collaboration between EMIB, BESIX and a new venture to be set up from BESIX around Clean Air by summer 2022 (the 'NewCo' ) is a stepping stone to follow-up research, where the adaptations to other subsystems could be the subject of new funding requests. As part of this bigger story, BESIX /the NewCo and EMIB are committed to a long-term collaboration with other UA research groups. The objective is to achieve a win-win for all parties and to make Clean Air a self-sustaining, socially relevant investment within a circular and green building context. The further development of Clean Air is part of the expansion of the research and valorisation programme on "Green Building" of EMIB, which has common ground with each of the 3 spearhead domains of UAntwerpen. Strengthening this programme has the potential to bring together expertise from different research groups of UAntwerpen and make them work together towards a strong BlueApp community.

Researcher(s)

• Promoter: Audenaert Amaryllis
• Co-promoter: Belmans Bert
• Co-promoter: Blom Johan

Research team(s)

• Energy and Materials in Infrastructure and Buildings

Project type(s)

• Research Project

Abstract

This research proposes a new development in the restoration sector is presented. This development consists of the application of 3D printed geopolymers in stone-built heritage. Stone-built heritage plays a significant role in the past as well as in today's society. Numerous structures, sculptures and other decorations are made in stone, ranging from purely functional structures to structures of significant historical and cultural value. Stone has quantitative properties, such as durability, which is why it is associated with longevity. However, the stone is not an inert material. It undergoes changes in appearance and functional capacity that can be understood as surface processes that lead to degradation, ultimately with an overall loss of value (damage). Currently, the conventional restoration method is the use of repair mortars. Repair mortars are an efficient way of preservation, aiming at maximum preservation of the original material. However, they also have many drawbacks, the main one being the lack of compatibility with the original material. It will eventually cause damage to the substrate. It is a very well-founded reason to look beyond the known and established products and methods from the restoration sector and conduct multidisciplinary research. By combining engineering and materials science with restoration sciences, we can develop new methods. A new method that can result from this is the application of 3D printed geopolymers. Geopolymers are stone-like materials which are placed between binders, such as cement and ceramics. The properties can be strongly influenced. Different types of geopolymers exist, depending on the system through which they are activated. In this study, we would like to focus on alkali-activated geopolymers because they can be manufactured from waste materials. In this way, this is a circular material, and therefore CO2 production is significantly reduced. An additional advantage of using alkali-activated geopolymers is that the equipment to print this type of geopolymer already exists (but we do not rule out the possible use of other types of geopolymers in the future). By conducting this research, a new and innovative working method can be developed for the restoration industry. It will improve the restoration process so that our stone heritage can be well preserved for later generations, despite the degradation processes of stone. At the same time, this research also yields a sustainable method, which will be crucial for later generations to continue to admire the heritage.

Researcher(s)

• Promoter: De Kock Tim
• Co-promoter: Blom Johan

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

This project is being carried out by the University of Antwerp and VITO, and supported by the Belgian Road Research Centre (BRRC). Two possible solutions are being investigated to prevent the release of zinc from rubber granules; on the one hand by coating the rubber granules (UAntwerp) and on the other hand by trapping the released harmful components in a sorbent before they are released into the environment (VITO). Possible solutions can, be developed further at a later stage (phase II) and can be used for many applications of rubber granulates where environmental problems play a role. In the follow-up research, attention will also be paid to the recyclability and durability of both solutions (influence of ageing and/or exceptional weather conditions).

Researcher(s)

• Promoter: Vuye Cedric
• Co-promoter: Billen Pieter
• Co-promoter: Blom Johan
• Co-promoter: Blust Ronny
• Co-promoter: Dardenne Freddy
• Co-promoter: Vande Velde Christophe
• Co-promoter: Verbruggen Sammy

Research team(s)

• Sustainable Pavements and Asphalt Research (SuPAR)

Project type(s)

• Research Project

Abstract

Assessment of new Crumb rubber (CR) proposals for Green.er The aims of this project are the following: 1. A summary of the relevant legislation when using crumb rubber as a building material for Flanders, Walloon region, Brussels and the European Union; 2. A position paper on ecotoxicity regarding the possible risks of combinations of toxic substances, even when the individual contaminants are within their quality standards incorporated in legislation. The document will inform on ecotoxicological risk related to substances and mixtures, on expected changes in legislation (e.g. surface water), and methodologies related to ecotoxicological risk assessment; 3. A checklist for new applicants related to environmental concerns (leaching, VOC emissions, ecotoxicity, …); 4. Assessment of new project proposals for Greener by a group of experts, limited to the potential environmental impact.

Researcher(s)

• Promoter: Blom Johan
• Co-promoter: Dardenne Freddy
• Co-promoter: Teuchies Johannes
• Co-promoter: Vuye Cedric

Research team(s)

Project type(s)

• Research Project

Abstract

In Flanders, more and more attention is being paid to sustainable road structures, but rather to the pavement. In the next decades, we will also have to renew the foundations and sub-foundations of existing roads in the most sustainable way possible. Only this will allow us to perpetuate our road infrastructure, which is of primary economic and social importance, for generations to come. Abroad, we see more and more innovative use of materials for foundations: new material types (e.g geopolymers) and production technologies (e.g. emulsions, foamed bitumen). In this project, one of the promising innovative technologies was deployed: recycling old asphalt pavements into bonded foundations with foamed bitumen technology. With this technology, the existing asphalt is first milled off and crushed into an aggregate. The aggregate is then processed with a hydraulic binder and foamed bitumen to form a semi-bound mixture (FOAM). FOAM is then transported to the site and compacted (cold), just like unbound foundation material. Optionally, the process can even be done in situ, with emulsion and the foundation present. In this project, the asphalt was crushed and reduced to granules near the job site and mixed in ambient temperature to form a bitumen-bonded mixture. Being able to mill, mix and process on site mainly saves transport, leading to a lower environmental impact and economic balance. This project included a market study, an elaborated lab methodology to design quality mixtures with an alternative compaction that is more applicable to contractors, process control guidelines, an elaborated road design methodology with standard structures, the construction of two trial sections with different sections and a comprehensive LCA-LCCA calculation showing that this road structure is a favourable alternative to bonded and unbonded foundations. The use of FOAM allows more road construction materials to be economically recycled on site, with equivalent mechanical quality and less environmental impact.

Researcher(s)

• Promoter: Van den bergh Wim
• Co-promoter: Audenaert Amaryllis
• Co-promoter: Blom Johan
• Co-promoter: Craeye Bart
• Co-promoter: Vuye Cedric

Research team(s)

Project website

Project type(s)

• Research Project

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.

Researcher(s)

• Promoter: Vuye Cedric
• Co-promoter: Audenaert Amaryllis
• Co-promoter: Blom Johan
• Co-promoter: Van den bergh Wim

Research team(s)

• Sustainable Pavements and Asphalt Research (SuPAR)

Project type(s)

• Research Project

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.

Researcher(s)

• Promoter: Vuye Cedric
• Co-promoter: Blom Johan
• Co-promoter: Denys Siegfried
• Co-promoter: Tytgat Tom
• Co-promoter: Van den bergh Wim

Research team(s)

Project type(s)

• Research Project

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.

Researcher(s)

• Promoter: Vuye Cedric
• Co-promoter: Blom Johan
• Co-promoter: Van den bergh Wim

Research team(s)

Project type(s)

• Research Project

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.

Researcher(s)

• Promoter: Van den bergh Wim
• Co-promoter: Blom Johan
• Co-promoter: Vuye Cedric

Research team(s)

Project type(s)

• Research Project

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).

Researcher(s)

• Promoter: Blom Johan
• Co-promoter: Van den bergh Wim
• Co-promoter: Vuye Cedric

Research team(s)

Project type(s)

• Research Project

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/rers/projects/highlighted/rejuvebit/

Researcher(s)

• Promoter: Van den bergh Wim
• Co-promoter: Audenaert Amaryllis
• Co-promoter: Blom Johan

Research team(s)

Project website

Project type(s)

• Research Project