The urban growth and the conservation of its infrastructure are the most significant global challenges of our age that demand research efforts to develop more sustainable and resilient construction materials. As the global need for building infrastructure increases to improve worldwide production, the construction industry needs more advanced materials with adaptive and multifunctional purposes that allow them to change their properties as response to the environmental and load-bearing stimuli they are exposed.
The LabMAT is helping to advance these efforts conducting research focused on the field of innovative construction materials from a vision of waste valorisation by introducing novel developments and methodologies that address the following emerging topics:
Self-healing Construction Materials
Asphalt and concrete are the two most used materials for infrastructure construction in the world. Therefore, extending the lifespan of these construction materials by reducing their maintenance is needed to promote a more resilient infrastructure. To address this, we are exploring new self-healing bituminous and cementitious materials from a vision of developing and characterization at multiple scales. Topics of interest include, but are not limited to: self-healing of bituminous materials by externally triggered heating by magnetic field technologies and addition of metallic waste, such as induction heating and microwave, and bioencapsulated rejuvenators to activate crack-healing by the effect of reconstitution of the chemical composition of the binder, and self-healing concrete by encapsulated agents.
Extrinsic self-healing of bituminous materials using encapsulated rejuvenators is a hot topic within road materials. Based on a circular economy vision for more sustainable and resilient asphalt pavements, this study explores for the first time the use of pyrolytic oil from waste tyres as a promising encapsulated rejuvenator to promote the extrinsic self-healing in bituminous materials. Pyrolytic oil-in-water emulsions, and capsules and their components were produced and characterised through gas chromatography-mass spectrometry (GC/MS) and SARA fractions analysis, fluorescence microscopy methods, creaming index, thermogravimetric analysis (TGA-DGT), optical and scanning electron microscopy (SEM), encapsulation efficiency and mechanical properties.
Norambuena-Contreras J, Arteaga-Pérez LE, Concha JL, Gonzalez-Torre I. Pyrolytic oil from waste tyres as a promising encapsulated rejuvenator for the extrinsic self-healing of bituminous materials. Road Materials and Pavement Design, 2021; 22(sup 1):117-133. [link]
This article presents an extensive and critical literature review of the processes of ageing, recovering and self-healing of bituminous materials, focusing on the use of rejuvenating agents to extend the life of pavements. Therefore, the different types and techniques to encapsulate rejuvenators, their evolution over the years, and their main applications in bituminous materials were analysed from a multiscale approach. Finally, based on the current trends in materials engineering, this article proposes advances and innovations to improve the future research in the field of encapsulated rejuvenators to promote asphalt self-healing, from a more sustainable point of view.
Gonzalez-Torre I, Norambuena-Contreras J. Recent advances on self-healing of bituminous materials by the action of encapsulated rejuvenators. Construction and Building Materials 2020; 258, 119568. [link]
Asphalt self-healing by encapsulated rejuvenating agents is considered a revolutionary technology for the autonomic crack-healing of aged asphalt pavements. This paper aims to explore the use of Bio-Oil (BO) obtained from liquefied agricultural biomass waste as a bio-based encapsulated rejuvenating agent for self-healing of bituminous materials. Novel BO capsules were synthesized using two simple dripping methods through dropping funnel and syringe pump devices, where the BO agent was microencapsulated by external ionic gelation in a biopolymer matrix of sodium alginate.
Norambuena-Contreras J, Arteaga-Perez LE, Guadarrama-Lezama AY, Briones R, Vivanco JF, Gonzalez-Torre I. Microencapsulated bio-based rejuvenators for the self-healing of bituminous materials. Materials 2020; 13, 1446. [link]
The management and disposal of solid waste from industrial sources is a problem around the world. There is currently an important necessity of recycling the waste materials generated by the industry to avoid environmental hazards. Several research efforts have been carried out to develop environmentally friendly materials based on waste valorisation. To address this, we are researching the use of several wastes from industrial sources and renewable resources to develop more sustainable construction materials with improved properties. Topics of interest include, but are not limited to: recycled rubber membranes reinforced with crushed polyethylene particles, cement mortars and bituminous materials modified with carbon and iron powder waste, steel shavings and wool fibres, recycled brass fibres, lignins, along with earth-based materials reinforced with jute fibres, and recent research on the production of biopolymers and bitumen rejuvenators through thermochemical conversion from biomass waste, as well from waste tyre rubber.
This paper reports part of an international research project with the long-term aim of developing more sustainable asphalt mixture with crack-healing properties by the addition of recycled metallic waste from industrial sources. Specifically, this article presents an evaluation of the physical, thermophysical, and mechanical properties of asphalt mixtures with metallic fiber obtained from recycled tires for crack-healing purposes.
González A, Norambuena-Contreras J, Poulikakos L, Varela MJ, Valderrama J, Flisch A, Arraigada M. Evaluation of asphalt mixtures containing metallic fibers from recycled tires to promote crack-healing. Materials 2020; 13, 5731. [link]
Recycled rubber powder from shredded End of Life Tyres (ELTs) has been used for the development of a new membrane as sustainable construction material. Four different membranes with the same rubber powder gradation, but with four different percentages of crushed polyethylene particles and pre-conditioned under four different environmental conditions (dry, water-saturated, cold and ageing) have been considered. The influence of polyethylene particles on the mechanical behaviour of the membranes has been evaluated using tensile strength tests.
Norambuena-Contreras J, Silva-Robles E, Gonzalez-Torre I, Saravia-Montero Y. Experimental evaluation of mechanical and thermal properties of recycled rubber membranes reinforced with crushed polyethylene particles. Journal of Cleaner Production 2017;145:85-97. [link]
Multifunctional construction materials are the materials that perform multiple functions in a system or structure due to their specific intrinsic or extrinsic properties. These innovative construction materials can be both naturally existing and specially engineered. For instance, numerous multifunctional materials can be found in nature. Biomaterials typically contain sensing, healing, activating, and other functions built into the primary structures of an organism that respond to the environmental and load-bearing stimuli to which they are exposed. Focused on this purpose, we are exploring engineered materials for infrastructure construction with multifunctional properties such as, self-sensitive, self-monitoring, bio-inspired and energy harvesting. Topics of interest include, but are not limited to: bituminous materials with electromagnetic heating-sensitive and energy harvesting properties, and recent research on bio-inspired cement-based materials.
This paper presents the first analysis on the evaluation of the thermophysical and heating performance of self-healing asphalt mixtures with different contents of steel wool fibres for their potential use as a solar radiation absorbing material in an asphalt solar collector prototype.
Concha JL, Norambuena-Contreras J. Thermophysical properties and heating performance of self-healing asphalt mixture with fibres and its application as a solar collector. Applied Thermal Engineering, 2020, 115632. [link]