Strain Monitoring of Concrete Using Carbon Black-Based Smart Coatings
Abstract: Given the challenges we face of an ageing infrastructure and insufficient maintenance, there is a critical shift towards preventive and predictive maintenance in construction. Self-sensing cement-based materials have drawn interest in this sector due to their high monitoring performance and durability compared to electronic sensors. While bulk applications have been well-discussed within this field, several challenges exist in their implementation for practical applications, such as poor workability and high manufacturing costs at larger volumes. This paper discusses the development of smart carbon-based cementitious coatings for strain monitoring of concrete substrates under flexural loading. This work presents a physical, electrical, and electromechanical investigation of sensing coatings with varying carbon black (CB) concentrations along with the geometric optimisation of the sensor design. The optimal strain-sensing performance, 55.5 ± 2.7, was obtained for coatings with 2 wt% of conductive filler, 3 mm thickness, and a gauge length of 60 mm. The results demonstrate the potential of applying smart coatings with carbon black addition for concrete strain monitoring.
Reference of this article: Milone, Gabriele, Christos Vlachakis, Jean-Marc Tulliani, and Abir Al-Tabbaa. 2024. "Strain Monitoring of Concrete Using Carbon Black-Based Smart Coatings" Materials 17, no. 7: 1577.
Affiliations:
Gabriele Milone, Christof Vlachakis and Abir Al-Tabbaa: Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK
Jean-Marc Tulliani: Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin 10129, Italy
Modification of Concrete Mix Design with Crystalline Admixture for Self-healing Improvement
Abstract: Current practice reveals that no adaptation of self-healing concrete mix designs are made for the introduction of healing agents. However, the inclusion of healing agent may downgrade the concrete properties to some extent. Therefore, an optimization of mix design is necessary in order to eliminate the possible negative effects induced by the healing agents and also to potentially improve the self-healing and self-sealing abilities. In this paper, seven concrete mix designs were studied with crystalline admixture (CA) as a prospective healing agent to stimulate the autogenous healing mechanism. Several design parameters were opted namely (1) dosage of CA from 0 to 2% by cement mass, (2) water-cement (w/c) ratio between 0.46 and 0.52, and (3) cement content in the range of 320 to 360 kg/m3. The self-healing and self-sealing performances were investigated by the indicators of crack closure and the permeability rate, respectively. Results showed that the addition of CA demonstrated an advanced progress on the crack closure with increasing the healing time. The size of the crack considerably influenced healing performance. All in all, the effects of mix design parameters in terms of improvements of healing and sealing efficiencies are discussed and a recommendation for optimizing the mix design is proposed.
Reference of this article: Harry Hermawan, Virginie Wiktor, Pedro Serna, Elke Gruyaert, Modification of Concrete Mix Design with Crystalline Admixture for Self-healing Improvement, Journal of Advanced Concrete Technology, 2024, Volume 22, Issue 4, Pages 237-252, Released on J-STAGE April 24, 2024, Online ISSN 1347-3913,
Affiliations:
Harry Hermawan and Elke Gruyaert: KU Leuven, Department of Civil Engineering, Materials and Constructions, Ghent Campus, Gebroeders De Smetstraat 1, 9000, Ghent, Belgium
Harry Hermawan and Pedro Serna: Instituto de Ciencia y Tecnología Del Hormigón (ICITECH), Universitat Politècnica de València, Camino de Vera S/n, 46022, Valencia, Spain
Virginie Wiktor: Cugla B.V., R&D Center, Rudonk 6b, 4824 AJ, Breda, The Netherlands
The use of additive manufacturing in self-healing cementitious materials: A state-of-the-art review
Abstract: This paper presents a state-of-the-art review on the application of additive manufacturing (AM) in self-healing cementitious materials. AM has been utilized in self-healing cementitious materials in three ways: (1) concrete with 3D-printed capsules/vasculatures; (2) 3D concrete printing (3DCP) with fibers or supplementary cementitious materials (SCMs); and (3) a combination of (1) and (2). 3D-printed capsules/vascular systems are the most extensively investigated, which are capable of housing larger volumes of healing agents. However, due to the dimension restraints of printers, most of the printed vasculatures/capsules are in small scale, making them difficult for upscaling. Meanwhile, 3DCP shows great potential to lower the environmental footprint of concrete construction. Incorporation of fibers and SCMs helps improve the autogenous healing performance of 3DCP. Besides, 3D-printed concrete with hollow channels as the vasculature could further improve the autonomous healing and scalability of self-healing cementitious materials. Finally, possible directions for future research are discussed.
Reference of this article: Zhi Wan, Yading Xu, Shan He, Erik Schlangen, Branko Šavija, The use of additive manufacturing in self-healing cementitious materials: A state-of-the-art review, Developments in the Built Environment, Volume 17, 2024, 100334, ISSN 2666-1659,
Affiliations:
Zhi Wan, Yading Xu, Shan He, Erik Schlangen, and Branko Šavija: Microlab, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, the Netherlands
Investigation of Membrane Emulsification for the Scaled Production of Microcapsules for Self-sealing Cementitious Systems
Abstract: Capsule-based self-sealing in cementitious systems is an advantageous methodology which has the potential to decrease water ingress and thus enhance a system’s durability and extend its lifespan. If capsule-based self-sealing is to be considered as an industrial solution, production must be scaled while capsule quality and batch reproducibility are maintained. In this study, polyurethane-shelled microcapsules containing a commercially available water repellent agent were produced using membrane emulsification equipment, supplied by Micropore Technologies, followed by interfacial polymerisation. Production was scaled across three different cross-flow membrane emulsification devices, the AXF-1, the AXF-3, and the AXF-4, increasing production output to a maximum of 850 L/hr of capsule suspension. Following production, capsules were characterised, measuring average size and size distribution, as well as integrated into a cementitious matrix. The results highlight the key parameters that govern capsule size, the versatility of the equipment, and the consistent quality of capsules produced. It is hoped that this scaled production of capsules will help to develop the commercial viability of capsule-based self-sealing cementitious systems.
Reference of this article: Investigation of Membrane Emulsification for the Scaled Production of Microcapsules for Self-sealing Cementitious Systems Claire Riordan, Dave Palmer and Abir Al-Tabbaa MATEC Web Conf., 378 (2023) 02010
Affiliations:
Claire Riordan, Dave Palmer and Abir Al-Tabbaa: Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK
Dave Palmer: Micropore Technologies Ltd, Wilton Centre, Redcar, TS10 4RF, UK
Corresponding author:
Towards a Conscious and Far-Sighted Construction Market Through the Use of Sustainability Indexes
Davide di Summa, Esteban Camacho, Liberato Ferrara, & Nele De Belie
Abstract: The ever-changing needs of the end user in the construction industry, together with the increasing awareness about the great influence of the sector on the worldwide sustainability, require some tools to be employed by the stakeholders to drive the market towards conscious and appropriate choices. An example in this regard are advanced cement-based materials that, either by partially replacing cement with supplementary cementitious materials and virgin aggregates with recycled ones or by increasing durability, are generating interest in the market thanks to their potentially better environmental performance. Therefore, besides the sustainability analyses such as the Life Cycle Assessment (LCA) and Life Cycle Cost (LCC) ones, some recent literature already tackled the problem proposing a more immediate evaluation approach represented by a series of indexes which are focused on the ecological and structural (generally, the compressive strength) performance of the material. To this end, from a comprehensive perspective, in this work two indexes are proposed able to include a wider range of environmental performances besides the costs and the durability characteristics. One is aimed to determine the suitability of using certain cementitious materials, encompassing the aforesaid parameters for the cubic meter scale. A second one is aimed to define the best mix design to be used to build certain structures (or components). For such purpose, the case of precast panels made with Ultra High Performance Concrete (UHPC) is here addressed, to assess the consistency of such indexes, upgrading from the material scale to the product scale.
Reference of this article:di Summa, D., Camacho, E., Ferrara, L., De Belie, N. (2023). Towards a Conscious and Far-Sighted Construction Market Through the Use of Sustainability Indexes. In: Ilki, A., Çavunt, D., Çavunt, Y.S. (eds) Building for the Future: Durable, Sustainable, Resilient. fib Symposium 2023. Lecture Notes in Civil Engineering, vol 349. Springer, Cham.
Affiliations:
Davide di Summa, and Nele De Belie: Department of Structural Engineering and Building Materials, Magnel-Vandepitte Laboratory, Ghent University, Tech Lane Ghent Science Park, Campus A, Technologiepark Zwijnaarde 60, 9052, Ghent, Belgium
Davide Di Summa,and L. Ferrara: Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
Esteban Camacho: RDC Research and Development Concretes, Calle Conde Altea 52, pta 3, 46005, València, Spain