Assessment of impact resistance recovery in Ultra High-Performance Concrete through stimulated autogenous self-healing in various healing environments

Niranjan Prabhu Kannikachalam, Paula Sofia Marin Peralta, Didier Snoeck, Nele De Belie and Liberato Ferrara

Abstract: Ultra High-Performance Concrete (UHPC) is widely acknowledged for its remarkable mechanical properties, owing to its compact microstructure. The response of UHPC to impact forces plays a vital role in ensuring the safety and longevity of structures, specifically in protective buildings, high-performance pavements and offshore concrete structures. In this context, this paper reports on an experimental investigation aimed at assessing the effects of stimulated autogenous self-healing of UHPC on the recovery of its performance under impact loadings. Drop weight tests were performed on UHPC slabs, with a 10 kg heavy impactor dropped from the height of 1 m on the centre of the specimens. Specimens were pre-cracked by repeated impacts up to 40% of their predetermined capacity. Pre-cracked specimens were exposed to different healing conditions, water submersion, 95% ± 5% RH, and wet/dry cycling (12/12 h) either in water or in a NaCl solution. Self-healing was evaluated through rebound height, elastic stiffness recovery, natural frequency, and laser displacement measurements. High-speed cameras and Digital Image Correlation were used to capture rebound height and crack formation. Performance was assessed at time 0, pre-damaging, 1, 2, and 4 months. After the healing period, all specimens were tested to failure. Specimens exhibited an increasing healing efficiency when moving from 95% ± 5% RH, over wet/dry cycling, to submerged conditions. Specimens healed continuously under submerged conditions exhibited a complete closure of surface cracks (50–150 μm) and an 80% recovery in natural frequency. Furthermore, they showed a more than 10% increase in stiffness and energy dissipation capacity after four months of healing.

Reference of this article:Niranjan Prabhu Kannikachalam, Paula Sofia Marin Peralta, Didier Snoeck, Nele De Belie, Liberato Ferrara, Assessment of impact resistance recovery in Ultra High-Performance Concrete through stimulated autogenous self-healing in various healing environments, Cement and Concrete Composites, Volume 143, 2023, 105239, ISSN 0958-9465,

Affiliations:

Niranjan Prabhu Kannikachalam, Paula Sofia Marin Peralta and Liberato Ferrara: Politecnico di Milano, Department of Civil and Environmental Engineering, piazza Leonardo da Vinci 32, 20133 Milan, Italy

Niranjan Prabhu Kannikachalam and Nele de Belie: Ghent University, Department of Structural Engineering and Building Materials, Magnel-Vandepitte Laboratory, Tech Lane Ghent Science Park, Campus A, Technologiepark Zwijnaarde 60, B-9052, Ghent, Belgium

Didier Snoeck: Building, Architecture and Town Planning (BATir) Department, Université Libre de Bruxelles, Belgium

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The full article can be found here: https://doi.org/10.1016/j.cemconcomp.2023.105239

 

      

Strain Monitoring of Concrete Using Carbon Black-Based Smart Coatings

Gabriele Milone, Christos Vlachakis, Jean-Marc Tulliani and Abir Al-Tabba

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

The full article can be found here: https://doi.org/10.3390/ma17071577

 

      

Modification of Concrete Mix Design with Crystalline Admixture for Self-healing Improvement

Harry Hermawan, Virginie Wiktor,Pedro Serna and Elke Gruyaert

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

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The full article can be found here: https://doi.org/10.3151/jact.22.237

 

The use of additive manufacturing in self-healing cementitious materials: A state-of-the-art review

Zhi Wan, Yading Xu, Shan He, Erik Schlangen, and Branko Šavija

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

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The full article can be found here: https://doi.org/10.1016/j.dibe.2024.100334

 

 

Investigation of Membrane Emulsification for the Scaled Production of Microcapsules for Self-sealing Cementitious Systems

Claire Riordan, Dave Palmer and Abir Al-Tabbaa

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

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The full article can be found here: https://doi.org/10.1051/matecconf/202337802010