scholarly journals Sustainable Development and Performance Evaluation of Marble-Waste-Based Geopolymer Concrete

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1924 ◽  
Author(s):  
Wei-Hao Lee ◽  
Kae-Long Lin ◽  
Ting-Hsuan Chang ◽  
Yung-Chin Ding ◽  
Ta-Wui Cheng

The key objective of this study was to develop marble-based geopolymer concrete and examine the viability of its application as a sustainable structural material for the construction industry. The results of the research demonstrated that marble-based geopolymer concrete can be developed, and its physical/mechanical properties were shown to have a very good performance. According to various experimental tests and a large-scale ready-mixed plant test, it was found that the marble-based geopolymer concrete displayed a good workability and was not easily influenced by temperature changes. The results showed that marble-based geopolymer concrete has an excellent potential for further engineering development in the future.

2021 ◽  

Concrete is the most versatile, durable and reliable material and is the most used building material. It requires large amounts of Portland cement which has environmental problems associated with its production. Hence, an alternative concrete – geopolymer concrete is needed. The general aim of this book is to make significant contributions in understanding and deciphering the mechanisms of the realization of the alkali-activated fly ash-based geopolymer concrete and, at the same time, to present the main characteristics of the materials, components, as well as the influence that they have on the performance of the mechanical properties of the concrete. The book deals with in-depth research of the potential recovery of fly ash and using it as a raw material for the development of new construction materials, offering sustainable solutions to the construction industry.


2019 ◽  
Vol 8 (4) ◽  
pp. 8336-8342

From decades it has been recognized that Geopolymer will considerably replace the role of cement in the construction industry. In general, Geopolymer exhibits the property of the peak compressive strength, minimal creep and shrinkage. In this current research paper, Geopolymer mortar is prepared by using GGBS and Fly ash. The mix proportions are of (100-60)%GGBS with Fly ash by 10% replacement. The alkali activators Na0H and Na2Sio3 are used in the study for two different molarities of 4&8. The ratio to Sodium silicates to sodium hydroxide is maintained from 1.5, 2, 2.5 & 3 were used. Mortars are prepared and studied the effect of molarities of alkali activators in their setting times and strengths


Author(s):  
D T Branson ◽  
P S Keogh ◽  
D G Tilley

This paper addresses a controller design methodology for the hydraulic actuation of non-linear multi-body systems. It takes account of system uncertainties, envisaged system changes through added mass, positioning speed requirements, and vibration control. A mathematical model developed in the companion paper, Part 1, describes an experimental multi-body structure that is actuated by a hydraulic system. It is used to generate H∞-based position and active vibration controllers to meet the actuation requirements at the design stage. Experimental tests were undertaken with the developed H∞ controllers to demonstrate their accuracy and stability of motion control. The results are compared to ‘base level’ tests completed using a more traditional proportional-integral (PI) controller. In contrast with the instability experienced using PI control, the design process associated with the H∞ controllers ensures accurate closed loop stability over the range of system variations.


2019 ◽  
Vol 262 ◽  
pp. 06006
Author(s):  
Aleksandra Krampikowska ◽  
Anna Adamczak – Bugno

Modern fiber-cement boards currently used in construction are made of natural raw materials such as cement, cellulose fibers and of polyvinyl alcohol (PVA) and water. They replaced the eternitic plates, which were harmful to health, originated by Ludwig Hatschek. Materials made of fiber-cement are used in construction industry as a building and finishing material for facades, internal walls and roofs. Therefore, they are exposed to environmental conditions including rainfall and temperature changes, and in particular to frequent temperature transition through 0°C in a 24-hour cycle (cyclic freezing-thawing). In addition, fibrous cement materials, primarily used as cladding elements, are exposed to exceptional conditions, which include the high temperature caused by fire. The article presents the results of experimental tests of flexural strength of cement fiber boards subjected to exceptional conditions, to which the operation of fire belongs. The paper also presents a proposal to use a non-destructive method of acoustic emission based on time-frequency analysis for testing fiber-cement boards. Interesting research results were obtained that allowed to trace the differences in the mechanisms of material destruction under the influence of the changing time of external factors.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1742
Author(s):  
Roberto Montanari ◽  
Alessandra Varone

FIMEC (flat-top cylinder indenter for mechanical characterisation) is an instrumented indentation test employing a cylindrical punch. It has been used to determine the mechanical properties of metallic materials in several applications of industrial interest. This work briefly describes the technique and the theory of indentation with a flat-ended punch. The flat indentation of metals has been investigated through experimental tests, and an equation has been derived to calculate the yield stress from the experimental data in deep indentation. The approach is supported by many data on various metals and alloys. Some selected case studies are presented in the paper: (i) crank manufacturing through pin squeeze casting; (ii) the evaluation of the local mechanical properties in a carter of complex geometry; (iii) the qualification of Al billets for extrusion; (iv) stress–relaxation tests on CuCrZr heat sinks; (v) the characterization of thick W coatings on CuCrZr alloy; (vi) the measure of the local mechanical properties of the molten-zone (MZ) and the heat-affected zone (HAZ) in welded joints. The case studies demonstrate the great versatility of the FIMEC test which provides information not available by employing conventional experimental techniques such as tensile, bending, and hardness tests. On the basis of theoretical knowledge and large amount of experimental data, FIMEC has become a mature technique for application on a large scale in industrial practice.


2019 ◽  
Vol 265 ◽  
pp. 07007
Author(s):  
Ruben Kazaryan

In engineering systems, which are used in construction industry and its production (buildings, constructions, roads), two fundamentally different ways of mechanical joint are used: non-collapsible and collapsible. Some architects relate non-collapsible objects to monolithic and consider their recycling as a difficult and expensive process. Compression joints on self-locking fittings can be considered as non-collapsible as well. A compression connection cannot be disassembled without destroying. Collapsible joint differs from non-collapsible by the following features: 1. You can disassemble it to original components according to a prior technology, identify and change defective elements or add some other components. 2. It requires periodic inspection and maintenance because of climatic conditions (temperature changes, pressure changes, wind loads, etc.), and the specificity of operation of this joint leads to a decrease in its mechanical properties. 3. It is forbidden to make them monolithic, so collapsible joints are mounted in an accessible way.


Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1110
Author(s):  
Hani Alanazi

For the same concrete quality, different types of coarse aggregates may result in different mechanical properties. This paper presents a study on the effect of aggregate types on the mechanical properties of two concretes, namely, geopolymer concrete (GP) and traditional Portland cement (TC) concrete. The mechanical properties were investigated through several large-scale tests. Moreover, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and laser scanning microscope (LSM) images were obtained to study the microstructure of tested mixes. The results revealed that the aggregate type has different effects on the mechanical properties of TC and GP, as they were behaving opposite to quartz and limestone aggregates. Microstructure analysis further confirmed the growth of well-bonded regions between the paste and aggregate in the GP with limestone aggregates, and the formation of several weak interfacial zones in concrete mixtures made with quartz aggregates. It was concluded that the mechanical properties of GP are very sensitive to the stiffness of aggregate, concentrations of stress, and the physical and chemical reactions occurring in the interfacial transition zone which may lead to improved or weakened bond strength between paste and aggregates.


2021 ◽  
Vol 16 (2) ◽  
pp. 173-199
Author(s):  
Nadine T. El Gazzar ◽  
Alberto T. Estévez ◽  
Yomna K. Abdallah

1. ABSTRACT Recently, developing sustainable architectural materials from renewable resources is gaining great interest. This interest is intended to alleviate the drawbacks of petroleum-based materials and their contribution in the escalation of CO2 emissions causing the current environmental deterioration. Achieving sustainability through developing efficient architectural materials have been always conditioned by technological advancements and economic potential. This has affected the architectural design and construction sectors, especially in times of disasters or economic crisis, resulting in paralysis in the architectural construction and material development. These effects were caused by the capitalization and centralization of architectural construction industries. The recent trend of self-sufficiency that had first emerged in environmental activities supporting recycling, environmental purification and conservation, oxygen, food, and electricity production, has extended to cover more sophisticated products, such as wearables, gadgets and architecture. Achieving self-sufficiency in architecture is of interest to multidisciplinary researchers who focus on developing both self-sufficient systems and materials as the two main components of the built environment. Developing architectural materials aims to provide cheap, recycled, renewable, environmentally friendly, durable and sustainable building material regardless of the possibility of the autonomous production of these materials on a popular democratic basis. Architectural building materials production was always and still is considered a massive industry that is centralized in major firms and LTDs, limiting the architectural construction process to the availability of major economic capacity. This centralization had its merits in forcing forward large-scale economies and vitalizing the architectural design and construction market, but only on the large scale; however, this centralization shows its drawbacks every time in disasters or economic crisis, causing almost total paralysis in the construction industry due to economic impotence caused by different reasons. Moreover, the centralization of the building and construction industry have affected developing communities, causing economic drawbacks and creating a ripple-like crisis in housing. In this paper, the authors propose the self-sufficiency approach in the development and production of sustainable architectural material from abundant and renewable microbial agents, in order to democratize and popularize material production on a domestic and personalized basis. The current work presents Bacterial Cellulose (BC) as a structural and membrane material in different architectural elements and applications, developed through simple and domestically applied procedures in order to create distributed and self-sufficient productive units for architectural materials production. The current study aims specifically at the easiness and simplification of the production practices and procedures of the biopolymers, and specifically bacterial cellulose for encouraging and establishing the popularization of self-sufficient production units of these renewable and abundant biopolymers. In this regard, the current study is part of the ongoing research on enhancing the mechanical properties of bacterial cellulose in order to use it for structural applications, that will be further developed in terms of medium optimization, bacterial cellulose production efficiency analysis, and material mechanical and physical properties testing. The following sections will contain a literature review on the chemical base and physical/mechanical properties of biopolymers including bacterial cellulose, followed by the experimental work conducted in this paper to develop bacterial cellulose as an architectural material. The results were further analyzed through formal and structural customization proposing possible applications in architectural design.


2018 ◽  
Vol 18 (2) ◽  
pp. 387-399 ◽  
Author(s):  
Maria Teresa Gomes Barbosa ◽  
White José dos Santos ◽  
Claudia Valéria Gávio Coura

Abstract The use of industrial waste has raised great interest regarding its potential of contributing both to the reduction of costs and to sustainable development. In this context, there has been an increasingly high number of studies addressing the use of alternative materials in the construction industry, especially when considering the difficulty in obtaining building materials near urban centers, which results in an increase in the final price due to transportation costs. This research has characterized and evaluated the use of crushed marble waste to replace natural sand in the production of mortar. Many admixtures of mortar were subject to research regarding their physical and mechanical properties. It has been concluded that mortars produced with sand made of crushed marble waste have improved mechanical properties when compared to traditional mortar.


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