scholarly journals Influence of Crystalline Admixtures and Their Synergetic Combinations with Other Constituents on Autonomous Healing in Cracked Concrete—A Review

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 440
Author(s):  
Yuanzhu Zhang ◽  
Runwei Wang ◽  
Zhi Ding
Keyword(s):  
High Performance ◽  
Research Progress ◽  
Cement Matrix ◽  
Future Research ◽  
Self Healing ◽  
Matrix Composites ◽  
Expansive Agent ◽  
Practical Engineering ◽  
Research Findings ◽  
Fundamental Research

Crystalline admixtures (CAs) are new materials for promoting self-healing in concrete materials to repair concrete cracks. They have been applied to tunnel, reservoir dam, road, and bridge projects. The fundamental research and development of CAs are needed concerning their practical engineering applications. This paper reviews the current research progress of commercial CAs, including self-made CA healing cracks; the composition of CA; healing reaction mechanism; the composition of healing products; distribution characteristics of healing products; the influence of service environment and crack characteristics on the healing performance of CA; and coupling healing performance of CA with fiber, expansive agent, and superabsorbent polymers. The current research findings are summarized, and future research recommendations are provided to promote the development of high-performance cement matrix composites.

scholarly journals Intrinsic Self-Healing Epoxies in Polymer Matrix Composites (PMCs) for Aerospace Applications

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 201
Author(s):  
Stefano Paolillo ◽  
Ranjita K. Bose ◽  
Marianella Hernández Santana ◽  
Antonio M. Grande
Keyword(s):  
High Performance ◽  
Polymer Matrix Composites ◽  
Critical Issue ◽  
General Description ◽  
Self Healing ◽  
Matrix Composites ◽  
Testing Procedures ◽  
Aerospace Applications ◽  
Polymer Properties ◽  
Healing Efficiency

This article reviews some of the intrinsic self-healing epoxy materials that have been investigated throughout the course of the last twenty years. Emphasis is placed on those formulations suitable for the design of high-performance composites to be employed in the aerospace field. A brief introduction is given on the advantages of intrinsic self-healing polymers over extrinsic counterparts and of epoxies over other thermosetting systems. After a general description of the testing procedures adopted for the evaluation of the healing efficiency and the required features for a smooth implementation of such materials in the industry, different self-healing mechanisms, arising from either physical or chemical interactions, are detailed. The presented formulations are critically reviewed, comparing major strengths and weaknesses of their healing mechanisms, underlining the inherent structural polymer properties that may affect the healing phenomena. As many self-healing chemistries already provide the fundamental aspects for recyclability and reprocessability of thermosets, which have been historically thought as a critical issue, perspective trends of a circular economy for self-healing polymers are discussed along with their possible advances and challenges. This may open up the opportunity for a totally reconfigured landscape in composite manufacturing, with the net benefits of overall cost reduction and less waste. Some general drawbacks are also laid out along with some potential countermeasures to overcome or limit their impact. Finally, present and future applications in the aviation and space fields are portrayed.

scholarly journals Materials for Production of High and Ultra-High Performance Concrete: Review and Perspective of Possible Novel Materials

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4304
Author(s):  
Markssuel Teixeira Marvila ◽  
Afonso Rangel Garcez de de Azevedo ◽  
Paulo R. de de Matos ◽  
Sergio Neves Monteiro ◽  
Carlos Maurício Fontes Vieira
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Review Article ◽  
Cement Matrix ◽  
Bibliographic Databases ◽  
Future Research ◽  
Chemical Additives ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
Essential Components

This review article proposes the identification and basic concepts of materials that might be used for the production of high-performance concrete (HPC) and ultra-high-performance concrete (UHPC). Although other reviews have addressed this topic, the present work differs by presenting relevant aspects on possible materials applied in the production of HPC and UHPC. The main innovation of this review article is to identify the perspectives for new materials that can be considered in the production of novel special concretes. After consulting different bibliographic databases, some information related to ordinary Portland cement (OPC), mineral additions, aggregates, and chemical additives used for the production of HPC and UHPC were highlighted. Relevant information on the application of synthetic and natural fibers is also highlighted in association with a cement matrix of HPC and UHPC, forming composites with properties superior to conventional concrete used in civil construction. The article also presents some relevant characteristics for the application of HPC and UHPC produced with alkali-activated cement, an alternative binder to OPC produced through the reaction between two essential components: precursors and activators. Some information about the main types of precursors, subdivided into materials rich in aluminosilicates and rich in calcium, were also highlighted. Finally, suggestions for future work related to the application of HPC and UHPC are highlighted, guiding future research on this topic.

A review on the mechanical properties of textile structural composite T-beams

2019 ◽  
Vol 90 (5-6) ◽  
pp. 710-727 ◽  
Author(s):  
Yiwei Ouyang ◽  
Xianyan Wu
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Raw Materials ◽  
Research Progress ◽  
Future Research ◽  
Research Directions ◽  
Structural Composite ◽  
Delamination Resistance ◽  
Application Potential ◽  
Future Research Directions

In order to review the most effective ways to improve the mechanical properties of composite T-beams and further increase their application potential, research progress on the mechanical properties of textile structural composite T-beams was summarized based on two-dimensional (2-D) ply structure composite T-beams, delamination resistance enhanced 2-D ply structure T-beams, and three-dimensional (3-D) textile structural composite T-beams; future research directions for composite T-beams were also considered. From existing literature, the research status and application bottlenecks of 2-D ply structure composite T-beams and T-beams with enhanced delamination resistance performance were described, as were the specific classification, research progress, and mechanical properties of 3-D textile structural composite T-beams. In addition, the superior mechanical properties of 3-D braided textile structural composite T-beams, specifically their application potential based on excellent delamination resistance capacity, were highlighted. Future research directions for composite T-beams, that is, the applications of high-performance raw materials, locally enhanced design, structural blending enhancement, functionality, and intelligence are presented in this review.

scholarly journals Recent Progress in Polymer-Containing Soft Matters for Safe Mining of Coal

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1706 ◽  
Author(s):  
Hetang Wang ◽  
Yunhe Du ◽  
Deming Wang ◽  
Botao Qin
Keyword(s):  
High Performance ◽  
Surfactant Solution ◽  
Dust Control ◽  
Research Progress ◽  
Future Research ◽  
Material System ◽  
Fire Control ◽  
Mine Fire ◽  
Soft Matters ◽  
Safe Mining

Safe mining is the premise and guarantee of sustainable development of coal energy. Due to the combination of excellent properties of polymers and traditional soft matters, polymer-containing soft matters are playing an increasingly important role in mine disaster and hazard control. To summarize the valuable work in recent years and provide reference and inspiration for researchers in this field, this paper reviewed the recent research progress in polymer-containing soft matters with respect to mine dust control, mine fire control, mine gas control and mine roadway support. From the perspective role of polymers in a material system, we classify mine polymer-containing soft matters into two categories. The first is polymer additive materials, in which polymers are used as additives to modify fluid-like soft matters, such as dust-reducing agents (surfactant solution) and dust-suppressing foams. The second is polymer-based materials, in which polymers are used as a main component to form high performance solid-like soft matters, such as fire prevention gels, foam gels, gas hole sealing material and resin anchorage agent. The preparation principle, properties and application of these soft matters are comprehensively reviewed. Furthermore, future research directions are also suggested.

scholarly journals Application Status and Research Progress of Resin Matrix Composites in Unmanned Underwater Vehicle

2021 ◽  
Vol 2133 (1) ◽  
pp. 012022
Author(s):  
Xiaoran Wei ◽  
Suli Xing ◽  
Dingjiang Wei
Keyword(s):  
High Performance ◽  
Underwater Vehicle ◽  
Research Progress ◽  
Resin Matrix ◽  
Utilization Rate ◽  
Matrix Composites ◽  
Specific Strength ◽  
Unmanned Underwater Vehicle ◽  
Resin Matrix Composite ◽  
Aerial Vehicle

Abstract Unmanned underwater vehicle (UUV) is a kind of underwater unmanned vehicle. In recent years, it has been widely used in civil and military fields. With the development of the unmanned underwater vehicle to multi-function, strong concealment, high performance and other directions, different kinds of resin matrix composite materials with excellent sound absorption, corrosion resistance, high specific strength characteristics, the utilization rate of unmanned underwater vehicle gradually increased and has broad development potential. In this paper, the application status and key technologies of resin-matrix composites in the field of unmanned aerial vehicle (UUV) are studied from two aspects of function and structure, and the technical trend of resin-matrix composites in the future UUV is described, and its development prospect is forecasted.

Research Progress on Carbon Nanotubes Reinforced Cement-Based Materials

2014 ◽  
Vol 629-630 ◽  
pp. 487-493
Author(s):  
Bao Min Wang ◽  
Shuai Liu ◽  
Yu Han
Keyword(s):  
Carbon Nanotubes ◽  
High Performance ◽  
Weight Fraction ◽  
Research Field ◽  
Research Progress ◽  
Cement Matrix ◽  
Cement Composites ◽  
Mechanical Stirring ◽  
Cement Based Materials ◽  
Reinforced Cement

For their remarkable properties, carbon nanotubes (CNTs) are considered as promising candidate for next generation of high performance and functional cement-based composites in 21st century. The paper focuses on the dispersibility, mechanical property, durability, conductivity and piezoresistivity properties of CNTs reinforced cement-based materials. A homogenous CNTs-suspension was obtained using the method which combined ultrasonic processing with mechanical stirring, electric-field introduction and surfactant decoration. The low weight fraction of CNTs improved the mechanical properties of CNTs/cement composites. The compressive strength and toughness were correspondingly improved. The added CNTs improved the sulfate attack resistance and impermeability properties of the prepared CNTs/cement mixes. Meanwhile, the added CNTs improved the pressure-sensitive, conductivity and electromagnetic absorption properties of the prepared mixes, which laid a foundation of multi-functional concrete and structure. It concludes that the key issue for CNTs/cement composites is the dispersibility and the compatibility of CNTs in cement matrix. The solving solutions are put forward. In the meantime, the further research prospects in this research field are forecasted.

Micromachining of Aluminum Alloys

2019 ◽  
Author(s):  
Ann Rumsey ◽  
Muhammad Jahan
Keyword(s):  
Aluminum Alloys ◽  
Process Development ◽  
Burr Formation ◽  
Future Research ◽  
Matrix Composites ◽  
Comprehensive Overview ◽  
Research Findings ◽  
Wrought Aluminum Alloys ◽  
Wrought Aluminum ◽  
Aluminum Metal Matrix Composites

This article provides a comprehensive overview of the machining of aluminum alloys, composites, and ceramics at micro scale. All major aspects of the micromachining of aluminum alloys including process descriptions, key research findings, applications, major challenges, and guidelines for future research have been covered in this article. Based on the literature, conventional micromachining processes, such as turning, milling, grinding, and drilling, have been found to be suitable for machining most of the cast and wrought aluminum alloys. On the other hand, nonconventional micromachining processes were approached for the micromachining of aluminum metal matrix composites and alumina ceramics. Some challenges and aspects in the area of micromachining of aluminum alloys that need future considerations are burr formation, tool wear, surface finish, microstructures and properties changes, and process development for advanced and hybrid micromachining.

scholarly journals Underlying indicators for measuring smartness of buildings in the construction industry

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Frank Ato Ghansah ◽  
De-Graft Owusu-Manu ◽  
Joshua Ayarkwa ◽  
Amos Darko ◽  
David J. Edwards
Keyword(s):  
Construction Industry ◽  
High Performance ◽  
Future Research ◽  
Building Performance ◽  
Content Type ◽  
Smart Building ◽  
Building Technology ◽  
Zero Energy Building ◽  
Research Findings ◽  
Analyse Data

PurposeThis study investigates the underlying indicators for measuring the smartness of buildings in the construction industry; where the Smart Building Technology (SBT) concept (which incorporates elements of the Zero Energy Building (NZEB) concept) could ensure efficient energy consumption and high performance of buildings.Design/methodology/approachAn overarching post-positivist and empirical epistemological design was adopted to analyze primary quantitative data collected via a structured questionnaire survey with 227 respondents. The mean ranking analysis and one-sample t-test were employed to analyse data.FindingsResearch findings revealed that the level of knowledge of smart building indicators is averagely high in the Ghanaian construction industry. Future research is required to evaluate the awareness level of Smart Building Technologies (SBTs) by construction professionals and identify barriers to its adoption.Originality/valueA blueprint guidance model (consisting of significant indicators for measuring building smartness) was developed to help improve building performance and inform policymakers.

scholarly journals Deep Learning Methods for Remote Heart Rate Measurement: A Review and Future Research Agenda

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6296
Author(s):  
Chun-Hong Cheng ◽  
Kwan-Long Wong ◽  
Jing-Wei Chin ◽  
Tsz-Tai Chan ◽  
Richard H. Y. So
Keyword(s):  
Heart Rate ◽  
Deep Learning ◽  
Vital Signs ◽  
Video Camera ◽  
Research Progress ◽  
Future Research ◽  
Physiological Signal ◽  
Future Research Agenda ◽  
Research Findings ◽  
Digital Healthcare

Heart rate (HR) is one of the essential vital signs used to indicate the physiological health of the human body. While traditional HR monitors usually require contact with skin, remote photoplethysmography (rPPG) enables contactless HR monitoring by capturing subtle light changes of skin through a video camera. Given the vast potential of this technology in the future of digital healthcare, remote monitoring of physiological signals has gained significant traction in the research community. In recent years, the success of deep learning (DL) methods for image and video analysis has inspired researchers to apply such techniques to various parts of the remote physiological signal extraction pipeline. In this paper, we discuss several recent advances of DL-based methods specifically for remote HR measurement, categorizing them based on model architecture and application. We further detail relevant real-world applications of remote physiological monitoring and summarize various common resources used to accelerate related research progress. Lastly, we analyze the implications of research findings and discuss research gaps to guide future explorations.

scholarly journals Electrical, Piezoresistive and Electromagnetic Properties of Graphene Reinforced Cement Composites: A Review

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3220
Author(s):  
Shengchang Mu ◽  
Jianguang Yue ◽  
Yu Wang ◽  
Chuang Feng
Keyword(s):  
Material Properties ◽  
High Performance ◽  
Cement Composite ◽  
Electromagnetic Properties ◽  
Cement Matrix ◽  
Future Research ◽  
Cement Composites ◽  
Preparation Methods ◽  
Reinforced Cement ◽  
Filler Dispersion

Due to their excellent combination of mechanical and physical properties, graphene and its derivatives as reinforcements have been drawing tremendous attention to the development of high-performance and multifunctional cement-based composites. This paper is mainly focused on reviewing existing studies on the three material properties (electrical, piezoresistive and electromagnetic) correlated to the multifunction of graphene reinforced cement composite materials (GRCCMs). Graphene fillers have demonstrated better reinforcing effects on the three material properties involved when compared to the other fillers, such as carbon fiber (CF), carbon nanotube (CNT) and glass fiber (GF). This can be attributed to the large specific surface area of graphene fillers, leading to improved hydration process, microstructures and interactions between the fillers and the cement matrix in the composites. Therefore, studies on using some widely adopted methods/techniques to characterize and investigate the hydration and microstructures of GRCCMs are reviewed and discussed. Since the types of graphene fillers and cement matrices and the preparation methods affect the filler dispersion and material properties, studies on these aspects are also briefly summarized and discussed. Based on the review, some challenges and research gaps for future research are identified. This review is envisaged to provide a comprehensive literature review and more insightful perspectives for research on developing multifunctional GRCCMs.

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