Use of concrete formulations based on dredging sand in the fabrication of tetrapods for protection of harbour dykes

MATEC Web of Conferences ◽

10.1051/matecconf/202134801005 ◽

2021 ◽

Vol 348 ◽

pp. 01005

Author(s):

Mehdi Hassoune ◽

Hassan Fatmaoui ◽

Jamal Chaoufi

Keyword(s):

Marine Environment ◽

Construction Materials ◽

Dredged Materials ◽

Port Structures ◽

Alternative Solutions

Port structures (quays and dykes) need an enormous consumption of materials, in particular concrete and its components, as well as sand, hence the need to develop alternative solutions using port dredging sand, estimated at thousands of tonnes through its use in the concrete that forms the blocks of the quay walls. After having demonstrated in a previous work the possibility of using the dredged sand from the port of Agadir in concrete formulations, the present work consists in showing the possibility of using the dredged sand from the port of Agadir in concrete formulations that can be used in the construction of concrete tetrapods from a concrete formulation based on dredged sand, more precisely 50% of the sand entering in the formulation is dredged sand extracted from the port of Agadir. The eventual use of dredged sand in the concrete of the tetrapods will lead to enormous gains in the quantities of sand and thus to a lower consumption of construction materials, and will also play a more important role in the preservation of the marine environment by avoiding the trapping of the dredged materials.

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Protection Coatings for the Underwater Part of Ship’s Hull

Journal of Maritime & Transportation Science ◽

10.18048/2018.00.04 ◽

2018 ◽

Vol 55 (1) ◽

pp. 59-70

Author(s):

Renato Ivce ◽

Matej Grubiša ◽

Darijo Mišković

Keyword(s):

Marine Environment ◽

Protective Coatings ◽

Construction Materials ◽

General Consideration ◽

Antifouling Paints ◽

Environment Friendly ◽

Marine Industry ◽

Useful Life ◽

Alternative Solutions ◽

Day By Day

In this article authors present a general consideration of the underwater part of ship’s hull protection by protective coatings, paying particular attention to antifouling paints. Following the presentation of the importance of ship’s hull maintenance and protection in order to make navigation safer and to keep the ship in operation for as long as possible, a summary is made of the main types of antifouling products used throughout the history up to the present time. As far back as a thousand years BC, people had developed techniques to protect objects from falling into disrepair and understood the importance of preserving construction materials in order to prolong their useful life and value. Marine industry has been developing day by day and attention is increasingly focused on the safety of ships and crews, as well as on the protection of marine environment. Tin-free self-polishing copolymer (SPC) and foul release technologies are currently applied, in addition to many alternative solutions being suggested. Modern approaches to effective environment-friendly antifouling systems and their performance are highlighted.

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Reinforcement Mechanism of Cement/Lime-Fly Ash Treated Sediments as Road Construction Materials

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.99-100.924 ◽

2011 ◽

Vol 99-100 ◽

pp. 924-927 ◽

Cited By ~ 1

Author(s):

Dong Xing Wang ◽

Hong Xing Wang ◽

Wen Zhao Chen

Keyword(s):

Fly Ash ◽

Mechanical Performance ◽

Construction Materials ◽

Road Construction ◽

Strength Test ◽

Point Of View ◽

Environment Friendly ◽

Reinforcement Mechanism ◽

Dredged Materials ◽

Compressive Strength Test

Solidified dredged materials as environment-friendly materials in construction domain are increasingly popular because of their better mechanical performance and low pollution. Based on the physical characteristic of dredged marine sediments, a series of tests, such as unconfined compressive strength test and tensile strength test, were performed to explore the mechanical properties of cement/lime-fly ash treated sediments for the beneficial use in road construction. Finally, the reinforcement mechanism of solidified sediments was explored by SEM tests from the point of view of the formation of CSH phases and the change in microstructure.

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The Ethical Significance of Antibiotic Resistance towards Aquaculture Practices

IIUM Medical Journal Malaysia ◽

10.31436/imjm.v17i2.993 ◽

2018 ◽

Vol 17 (2) ◽

Author(s):

Ahmed Jalal Khan Chowdhur ◽

Akbar John ◽

Dilruba Nasrin ◽

Abdurezak Abdulahi Hashi ◽

Suhaila Mohd Omar ◽

...

Keyword(s):

Antibiotic Resistance ◽

Marine Environment ◽

Animal Health ◽

Bacterial Flora ◽

Construction Materials ◽

Health Concern ◽

Living Standard ◽

Aquatic Animal ◽

Human Beings ◽

Animal Pathogens

In recent decade, aquaculture species, including fish are under danger from bio-aggressors like viruses, bacteria, parasites and fungi. These organisms harm either spontaneously or through aquatic animal husbandry practices or both. The chemicals employed in aquaculture are drugs like antibiotics used to treat diseases, chemicals introduced through construction materials and hormones used to alter the reproductive viability, sex and growth rates. Drugs used to treat disease are the most dangerous to the fish. These persistent antibiotics tend to increase antibiotic-resistant free-living bacteria, thereby altering the composition of normal marine and freshwater bacterial flora. Evidence suggests that these antibioticresistant organisms in the marine environment will, in turn, pass their antibiotic resistance genes to other bacteria including human and animal pathogens. Antibiotic treatment in aquaculture is achieved by medicated baths and medicated food. In both cases, the probability exists for antibiotics to pass into the environment, affecting wildlife, remaining in the environment for extended periods of time and exerting their antibiotic effects to human. In this manner, potential alterations of the diversity of the marine microbiota produced by antibiotics may alter the homeostasis of the marine environment and affect complex forms of life including fish, shellfish, marine mammals, and human beings. The contamination of surface waters with antimicrobials has become an increasing public health concern because of the emergence of multi-resistant pathogens. Efforts to make progress on these issues require us to raise, confront and enact some difficult ethical decisions that will affect the living standard of human. Nevertheless, excessive antibiotic use in aquaculture should be of high concern to the aquaculture industry and its regulators, to public officials dealing with human and animal health and with the preservation of the environment, and to non-governmental organizations dealing with these issues.

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THE APPLICABILITY OF DISINTEGRATION TESTS FOR COHESIVE ORGANIC SOILS

Journal of Environmental Engineering and Landscape Management ◽

10.3846/16486897.2014.919924 ◽

2015 ◽

Vol 23 (1) ◽

pp. 1-14 ◽

Cited By ~ 9

Author(s):

Anne-Katrin GROßE ◽

Stefan CANTRÉ ◽

Fokke SAATHOFF

Keyword(s):

Boundary Conditions ◽

Large Scale ◽

Erosion Resistance ◽

Construction Materials ◽

Aggregate Stability ◽

Organic Soils ◽

Fine Grained ◽

Evaluation Procedures ◽

Dredged Materials ◽

Top Soil

The use of ripened fine-grained organic dredged materials as construction materials, e.g. as top soil on slopes such as landfills or dikes, is an important contribution to environmental engineering science. The materials are legally considered a waste and need to be beneficially re-used. Therefore, not only standard geotechnical parameter shave to be determined but also their erosion resistance which is a particularly critical environmental parameter. There is a variety of different tests to determine the flow dependent erosion resistance of soils, such as the erosion function apparatus (Briaud et al. 2001). In this study, however, the focus lays on the aggregate stability as an indicator for the erosion resistance under static loading, which can be determined using wet sieving and disintegration tests. The disintegration tests after Weißmann (2003) and Endell (RPW 2006) have a similar setup; however, the specific boundary conditions for the tests as well as the evaluation procedures are different. Weißmann proposed his test to determine the erosion stability of dike cover materials while the Endell test should be used for mineral sealing liners in navigation channels. In this study both tests have been used to evaluate the aggregate stability of fine-grained organic dredged materials that have been installed in large-scale research dike facilities and in the recultivation layers of different landfills. The materials showed good visual performance with respect to rainfall induced erosion so far; however, problems in determining erosion and aggregate stability indices limit the value of the studies: both disintegration tests investigated have major limitations with respect to the organic soils tested. Particularly the evaluation methods are not suitable for the soils but also some boundary conditions are critical and are discussed in this paper. The gained knowledge is a valuable basis for the development of standard characterisation methods for dredged materials in environmental and geotechnical applications.

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Fly Ash

Linnaeus Eco-Tech ◽

10.15626/eco-tech.2012.009 ◽

2017 ◽

Author(s):

Anna Wilhelmsson

Keyword(s):

Fly Ash ◽

Environmental Protection Agency ◽

High Water ◽

Crushed Rock ◽

Filling Materials ◽

Dredged Materials ◽

Land Disposal ◽

Maintenance Dredging ◽

Port Structures ◽

New Framework

Over the next few years, more than one million m3 of contaminated sediments, with a muddy texture, high water ratio and low strength, shall be dredged annually in the development of ports and maintenance dredging of navigable waterways in Sweden. Dumping at sea is limited since the dredged materials are contaminated. Land disposal requires transports and land area and is thus high in costs. In the construction of new port areas, large volumes of crushed rock, etc. are normally used as construction filling materials. These materials can be replaced by stabilised and solidified dredged materials, with modified geotechnical properties. The method of stabilising / solidifying (s/s) contaminated dredged materials has been used internationally for a long period of time and in more recent years, even in the Nordic countries. In Sweden, for instance, the Port of Gävle and the Port of Oxelösund have received permissions to reuse s / s-treated contaminated dredged materials in the port structures. The Municipality of Oskarshamn have applied for permit and permission are expected in autumn 2012. The Municipality of Oskarshamn will receive funding from the Swedish Environmental Protection Agency for remediating the polluted sediments within the harbor basin. Reuse of the stabilized / solidified masses in a geotechnical structure is supported by the new Framework Directive (2008/98/EC) on waste where great emphasis is placed on recycling. Within some of the projects mentioned the potential of using fly ash as a complementary binder has been investigated. In the presentation some of the most interesting results will be presented.

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