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Qiao G, Chen F, Wang N, Zhang D. Spatio-temporal evolution analysis of the coupling situation of economic-social-ecological system in Guangdong. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:32406-32426. [PMID: 36462076 PMCID: PMC9734722 DOI: 10.1007/s11356-022-24444-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
The economic and social structures of Chinese cities are constantly transforming in recent years. The coordinated development of economic, social, and ecological environment is an important path to achieving the construction of high-quality development. Taking Guangdong Province, the largest economic province in China, as an example, the evaluation index systems of economic development system (ED), social development system (SD), and ecological environment system (EE) are constructed, respectively. The entropy weight method and comprehensive evaluation method are applied to measure the evaluation indexes of economic, social, and ecological environment levels of each city in Guangdong Province from 2010 to 2020. The coupled coordination model is used to measure the spatial and temporal evolution of the coupled ED-SD-EE coordination of Guangdong cities and explore the impact of the epidemic on the coupling coordination degree. The results concluded that (i) the economic, social, and ecological environment of each city in Guangdong Province will be more harmonious from 2010 to 2020. ED-SD-EE coupling coordination of Guangdong cities shows a "rising and then declining" trend, but it is still in a "high coupling-low coordination" development state. (ii) The lagging development of the coupled ED-SD-EE system in Guangdong cities is mainly the ecological environment system. (iii) Epidemic harms the coupling and coordination of Guangdong cities, with the most negative effect on the coordination development of the EE. The paper findings clarify the current state of ED-SD-EE coupling and coordination in Guangdong cities, with a view to providing a reference basis for policy formulation and research on quality urban development.
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Affiliation(s)
- Guotong Qiao
- School of Economics and Management, Anhui University of Science and Technology, Huainan, 232001 Anhui China
- Dean’s Office and Innovation College, Anhui University of Science and Technology, Huainan, 231001 Anhui China
| | - Fei Chen
- School of Economics and Management, Anhui University of Science and Technology, Huainan, 232001 Anhui China
| | - Na Wang
- School of Economics and Management, Anhui University of Science and Technology, Huainan, 232001 Anhui China
| | - Dandan Zhang
- School of Economics and Management, Anhui University of Science and Technology, Huainan, 232001 Anhui China
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Amran M, Onaizi AM, Fediuk R, Vatin NI, Muhammad Rashid RS, Abdelgader H, Ozbakkaloglu T. Self-Healing Concrete as a Prospective Construction Material: A Review. MATERIALS 2022; 15:ma15093214. [PMID: 35591554 PMCID: PMC9106089 DOI: 10.3390/ma15093214] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 01/20/2023]
Abstract
Concrete is a material that is widely used in the construction market due to its availability and cost, although it is prone to fracture formation. Therefore, there has been a surge in interest in self-healing materials, particularly self-healing capabilities in green and sustainable concrete materials, with a focus on different techniques offered by dozens of researchers worldwide in the last two decades. However, it is difficult to choose the most effective approach because each research institute employs its own test techniques to assess healing efficiency. Self-healing concrete (SHC) has the capacity to heal and lowers the requirement to locate and repair internal damage (e.g., cracks) without the need for external intervention. This limits reinforcement corrosion and concrete deterioration, as well as lowering costs and increasing durability. Given the merits of SHCs, this article presents a thorough review on the subject, considering the strategies, influential factors, mechanisms, and efficiency of self-healing. This literature review also provides critical synopses on the properties, performance, and evaluation of the self-healing efficiency of SHC composites. In addition, we review trends of development in research toward a broad understanding of the potential application of SHC as a superior concrete candidate and a turning point for developing sustainable and durable concrete composites for modern construction today. Further, it can be imagined that SHC will enable builders to construct buildings without fear of damage or extensive maintenance. Based on this comprehensive review, it is evident that SHC is a truly interdisciplinary hotspot research topic integrating chemistry, microbiology, civil engineering, material science, etc. Furthermore, limitations and future prospects of SHC, as well as the hotspot research topics for future investigations, are also successfully highlighted.
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Affiliation(s)
- Mugahed Amran
- Department of Civil Engineering, College of Engineering, Prince Sattam Bin Abdulaziz University, Alkharj 16273, Saudi Arabia
- Department of Civil Engineering, Faculty of Engineering and IT, Amran University, Amran 9677, Yemen
- Correspondence: or
| | - Ali M. Onaizi
- School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor, Malaysia;
| | - Roman Fediuk
- Polytechnic Institute, Far Eastern Federal University, 690922 Vladivostok, Russia;
- Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia;
| | | | | | - Hakim Abdelgader
- Department of Civil Engineering, Faculty of Engineering, University of Tripoli, Tripoli 13275, Libya;
| | - Togay Ozbakkaloglu
- Ingram School of Engineering, Texas State University, San Marcos, TX 78666, USA;
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Tesfamariam BB, Seyoum R, Andoshe DM, Terfasa TT, Ahmed GMS, Badruddin IA, Khaleed H. Investigation of Self-Healing Mortars with and without Bagasse Ash at Pre- and Post-Crack Times. MATERIALS 2022; 15:ma15051650. [PMID: 35268883 PMCID: PMC8911208 DOI: 10.3390/ma15051650] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/25/2022] [Accepted: 02/07/2022] [Indexed: 02/06/2023]
Abstract
Cracks in typical mortar constructions enhance water permeability and degrade ions into the structure, resulting in decreased mortar durability and strength. In this study, mortar samples are created that self-healed their cracks by precipitating calcium carbonate into them. Bacillus subtilus bacterium (10−7, 10−9 cells/mL), calcium lactate, fine aggregate, OPC-cement, water, and bagasse ash were used to make self-healing mortar samples. Calcium lactates were prepared from discarded eggshells and lactic acid to reduce the cost of self-healing mortars, and 5% control burnt bagasse ash was also employed as an OPC-cement alternative. In the presence of moisture, the bacterial spores in mortars become active and begin to feed the nutrient (calcium lactate). The calcium carbonate precipitates and plugs the fracture. Our experimental results demonstrated that cracks in self-healing mortars containing bagasse ash were largely healed after 3 days of curing, but this did not occur in conventional mortar samples. Cracks up to 0.6 mm in self-healing mortars were filled with calcite using 10−7 and 10−9 cell/mL bacteria concentrations. Images from an optical microscope, X-ray Diffraction (XRD), and a scanning electron microscope (SEM) were used to confirm the production of calcite in fractures. Furthermore, throughout the pre- and post-crack-development stages, self-healing mortars have higher compressive strength than conventional mortars. The precipitated calcium carbonates were primed to compact the samples by filling the void spaces in hardened mortar samples. When fissures developed in hardened mortars, bacteria became active in the presence of moisture, causing calcite to precipitate and fill the cracks. The compressive strength and flexural strength of self-healing mortar samples are higher than conventional mortars before cracks develop in the samples. After the healing process of the broken mortar parts (due to cracking), self-healing mortars containing 5% bagasse ash withstand a certain load and have greater flexural strength (100 kPa) than conventional mortars (zero kPa) at 28 days of cure. Self-healing mortars absorb less water than typical mortar samples. Mortar samples containing 10−7 bacteria cells/mL exhibit greater compressive strength, flexural strength, and self-healing ability. XRD and SEM were used to analyze mortar samples with healed fractures. XRD, FTIR, and SEM images were also used to validate the produced calcium lactate. Furthermore, the durability of mortars was evaluated using DTA-TGA analysis and water absorption tests.
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Affiliation(s)
- Belay Brehane Tesfamariam
- Department of Materials Science and Engineering, Adama Science and Technology University, Adama 1888, Ethiopia; (R.S.); (D.M.A.)
- Correspondence: or
| | - Redeat Seyoum
- Department of Materials Science and Engineering, Adama Science and Technology University, Adama 1888, Ethiopia; (R.S.); (D.M.A.)
| | - Dinsefa Mensur Andoshe
- Department of Materials Science and Engineering, Adama Science and Technology University, Adama 1888, Ethiopia; (R.S.); (D.M.A.)
| | - Tatek Temesgen Terfasa
- Department of Chemical Engineering, Adama Science and Technology University, Adama 1888, Ethiopia;
| | - Gulam Mohammed Sayeed Ahmed
- Program of Mechanical Design and Manufacturing Engineering, School of Mechanical, Chemical and Materials Engineering, (So-M-C-M-E), Adama Science and Technology University, Adama 1888, Ethiopia;
- Center of Excellence (COE) for Advanced Manufacturing Engineering, Program of Mechanical Design and Manufacturing Engineering, School of Mechanical, Chemical and Materials Engineering, (So-M-C-M-E), Adama Science and Technology University, Adama 1888, Ethiopia
| | - Irfan Anjum Badruddin
- Research Center for Advanced Materials Science (RCAMS), King Khalid University, Asir 61413, Saudi Arabia;
- Mechanical Engineering Department, College of Engineering, King Khalid University, Abha 61421, Saudi Arabia
| | - H.M.T. Khaleed
- Department of Mechanical Engineering, Faculty of Engineering, Islamic University of Madinah, Madinah Munawara 42351, Saudi Arabia;
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