scholarly journals Iron and Aluminium Production Wastes as Exclusive Components of Alkali Activated Binders—Towards a Sustainable Alternative

2021 ◽  
Vol 13 (17) ◽  
pp. 9938
Author(s):  
Nuno Cristelo ◽  
Fernando Castro ◽  
Tiago Miranda ◽  
Zahra Abdollahnejad ◽  
Ana Fernández-Jiménez
Keyword(s):  
Co2 Emissions ◽  
Building Materials ◽  
Negative Impact ◽  
Raw Materials ◽  
Construction Materials ◽  
Heat Of Hydration ◽  
Sustainable Construction ◽  
Alkaline Solutions ◽  
By Products ◽  
Alkali Activated

The sustainability of resources is becoming a worldwide concern, including construction and building materials, especially with the alarming increase rate in global population. Alternative solutions to ordinary Portland cement (OPC) as a concrete binder are being studied, namely the so-called alkali-activated cements (AAC). These are less harmful to the environment, as lower CO2 emissions are associated with their fabrication, and their mechanical properties can be similar to those of the OPC. The aim of developing alkali-activated materials (AAM) is the maximization of the incorporated recycled materials, which minimises the CO2 emissions and cost, while also achieving acceptable properties for construction applications. Therefore, various efforts are being made to produce sustainable construction materials based on different sources and raw materials. Recently, significant attention has been raised from the by-products of the steelmaking industry, mostly due to their widespread availability. In this paper, ladle slag (LS) resulting from steelmaking operations was studied as the main precursor to produce AAC, combined with phosphating bath sludge—or phosphate sludge (PS)—and aluminium anodising sludge (AS), two by-products of the surface treatment of metals, in replacement rates of 10 and 20 wt.%. The precursors were activated by two different alkaline solutions: a combination of commercial sodium hydroxide and sodium silicate (COM), and a disposed solution from the cleaning of aluminium extrusion steel dies (CLE). This study assesses the influence of these by-products from the steelmaking industry (PS, AS and CLE) on the performance of the alkali-activated LS, and specifically on its fresh and hardened state properties, including rheology, heat of hydration, compressive strength and microstructure and mineralogy (X-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy and Fourier transform infra-red. The results showed that the CLE had no negative impact on the strength of the AAM incorporating PS or/and AS, while increasing the strength of the LS alone by 2×. Additionally, regardless of the precursor combination, the use of a commercial activator (COM) led to more fluid pastes, compared with the CLE.

Fundamentals of Geopolymers and Related Alkali Activated Materials

2014 ◽  
Vol 803 ◽  
pp. 144-147 ◽  
Author(s):  
J. Temuujin ◽  
A. Minjigmaa ◽  
U. Bayarzul ◽  
Ts. Zolzaya ◽  
B. Davaabal ◽  
...  
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Raw Materials ◽  
Construction Materials ◽  
Materials Chemistry ◽  
Low Carbon ◽  
Pond Ash ◽  
Sustainable Usage ◽  
By Products ◽  
Alkali Activated

With the increasing rate of depletion of natural raw materials for production of building materials, their sustainable usage is clearly an important topic for consideration. For instance, 1 tonne ordinary Portland cement (OPC) requires 1.7 tonnes of raw materials, 1.0 tonne of coal and 100 kWh of electricity. One tonne of cement emits 0.8 - 1 tonne of CO2 into atmosphere globally contributing ~5% of total manmade carbon dioxide. Therefore, the development of new, sustainable, low carbon footprint construction materials is an important task for materials scientists and civil engineers. One type of binder that is attracting particular attention around the world is alkali-aluminosilicate chemistry based material the so-called geopolymers. In this presentation we will discuss the fundamentals of geopolymer chemistry and the similarities to and differences from conventional alkali activated materials chemistry. Particular attention will be given to our latest results on the preparation of geopolymer type paste and concrete from fly ash. Mechanical activation of fly ash caused a decrease in porosity with a partial amorphisation of the crystalline constituents. Geopolymer type paste prepared from 30 minute milled Darkhan pond ash showed increase in 7 day compressive strengths by 7 times reaching of 15.4 (4.6) MPa. Keywords: Geopolymer binder, alkali-activated materials, coal combustion by products

Sustainable Construction Materials

2019 ◽  
pp. 658-687 ◽  
Author(s):  
R. V. Ralegaonkar ◽  
M. V. Madurwar ◽  
V. V. Sakhare
Keyword(s):  
Smart City ◽  
Raw Materials ◽  
Construction Materials ◽  
Raw Material ◽  
Sustainable Construction ◽  
City Development ◽  
Chemical Test ◽  
Physico Chemical ◽  
Increasing Demand ◽  
By Products

Due to ever increasing demand for the conventional construction materials as well as an increase in agro-industrial by-products it is essential to reuse these materials. As a smart city solution this chapter briefs an overview for the application of alternate raw materials as a principal source for the development of sustainable construction materials. The potential application of the discussed raw materials is elaborated as cementitious material, the aggregates as well as alternative reinforcement material. To understand the process of application, sustainable masonry product development is discussed in detail. In order to evaluate the feasibility of the raw material, the necessary physico-chemical test evaluation methods are also briefed. The developed end product performance evaluation is also discussed by desired tests as recommended by standards. The chapter concludes with a positive note that reuse of agro-industrial by-products is a feasible solution for the smart city development.

Green gold of Africa – Can growing native bamboo in Ethiopia become a commercially viable business?

2014 ◽  
Vol 90 (05) ◽  
pp. 628-635 ◽  
Author(s):  
Felix Böck
Keyword(s):  
Building Materials ◽  
Raw Materials ◽  
Construction Materials ◽  
Wood Products ◽  
Raw Material ◽  
Sustainable Construction ◽  
Sustainable Business ◽  
Subtropical Zone ◽  
New Construction ◽  
Increasing Demand

With concerns about climate change and the search for sustainable construction materials, significant attention is now being paid to Africa's natural resources. Ethiopia, known as Africa's political capital, has a rapidly expanding economy with increasing demand for new construction materials. Through public private partnerships projects the country is developing a sustainable business model to promote bamboo as a raw material. The subtropical zone of Ethiopia is home to approximately 65% of Africa's bamboo resources, an area of over 1 million hectares. Bamboo is potentially an ideal source of local, sustainable purpose-engineered building materials for growing cities not only in Ethiopia but across Africa. Production of conventional construction materials such as steel and concrete is expensive, highly energy intensive and unsustainable, requiring large quantities of water and is strongly dependent on imported raw materials. Bamboo is a renewable building material widely cultivated in Ethiopia but not yet utilized in modern construction. Structural Bamboo Products (SBP), similar to engineered wood products, have excellent potential to partially replace the use of more energy-intensive materials. Projects such as African Bamboo are taking steps in managing, cultivating and using Ethiopian bamboo species to help mitigate rapid deforestation in East Africa by creating alternative “wood” sources and sustainable business opportunities.

scholarly journals Radiological and physico-chemical characterization of red mud as an Al-containing precursor in inorganic binders for the building industry

2021 ◽  
Vol 36 (2) ◽  
pp. 182-191
Author(s):  
Ljiljana Kljajevic ◽  
Miljana Mirkovic ◽  
Sabina Dolenec ◽  
Katarina Ster ◽  
Mustafa Hadzalic ◽  
...  
Keyword(s):  
Construction Industry ◽  
Natural Radioactivity ◽  
Red Mud ◽  
Building Materials ◽  
Raw Materials ◽  
Construction Materials ◽  
Polymerization Process ◽  
Alkali Activation ◽  
Silica Alumina ◽  
Alkali Activated

The potential re-use of red mud in the building and construction industry has been the subject of research of many scientists. The presented research is a contribution to the potential solution of this environmental issue through the synthesis of potential construction materials based on red mud. A promising way of recycling these secondary raw materials is the synthesis of alkali-activated binders or alkali activated materials. Alkali-activated materials or inorganic binders based on red mud are a new class of materials obtained by activation of inorganic precursors mainly constituted by silica, alumina and low content of calcium oxide. Since red mud contains radioactive elements like 226Ra and 232Th, this may be a problem for its further utilization. The content of naturally occurring radionuclides in manufactured material products with potential application in the building and construction industry is important from the standpoint of radiation protection. Gamma radiation of the primordial radionuclides, 40K and members of the uranium and thorium series, increases the external gamma dose rate. However, more and more precedence is being given to limiting the radiological dose originating from building materials on the population these days. The aim of this research was to investigate the possible influence of alkali activation-polymerization processes on the natural radioactivity of alkali activated materials synthesized by red mud (BOKSIT a. d. Milici, Zvornik, Bosnia and Herzegovina) and their structural properties. This research confirmed that during the polymerization process the natural radioactivity was reduced, and that the process of alkali activation of raw materials has an influence on natural radioactivity of synthesized materials.

scholarly journals NORM waste, cements, and concretes. A review

2021 ◽  
Vol 71 (344) ◽  
pp. e259
Author(s):  
F. Puertas ◽  
J. A. Suárez-Navarro ◽  
M. M. Alonso ◽  
C. Gascó
Keyword(s):  
Natural Radioactivity ◽  
Industrial Waste ◽  
Building Materials ◽  
Raw Materials ◽  
Health Hazard ◽  
Sustainable Construction ◽  
Steel Mill ◽  
Portland Cements ◽  
Iron And Steel ◽  
By Products

The use of industrial waste and/or by-products as alternative sources of raw materials in building materials has become standard practice. The result, more sustainable construction, is contributing to the institution of a circular economy. Nonetheless, all necessary precautions must be taken to ensure that the inclusion and use of such materials entail no new health hazard for people or their environment. Due to the processes involved in generating industrial waste/by-products, these alternative or secondary materials may be contaminated with heavy metals, other undesirable chemicals or high levels of natural radioactivity that may constrain their use. In-depth and realistic research on such industrial waste is consequently requisite to its deployment in building materials. This paper reviews the basic concepts associated with radioactivity and natural radioactivity, focusing on industrial waste/by-products comprising Naturally Occurring Radioactive Materials (NORM) used in cement and concrete manufacture. Updated radiological data are furnished on such waste (including plant fly ash, iron and steel mill slag, bauxite and phosphogypsum waste) and on other materials such as limestone, gypsum and so on. The paper also presents recent findings on radionuclide activity concentrations in Portland cements and concretes not bearing NORMs. The role of natural aggregate in end concrete radiological behaviour is broached. The radiological behaviour of alternative non-portland cements and concretes, such as alkali-activated materials and geopolymers, is also addressed.

scholarly journals Construction Waste as a Resource in a Sustainable Built Environment

2020 ◽  
Vol 2020 (08) ◽  
pp. 28-36
Author(s):  
Martina Zbašnik-Senegačnik ◽  
Ljudmila Koprivec
Keyword(s):  
Life Cycle ◽  
Built Environment ◽  
Building Materials ◽  
Waste Treatment ◽  
Raw Materials ◽  
Construction Materials ◽  
Raw Material ◽  
Sustainable Construction ◽  
Construction Waste ◽  
Key Factor

The built environment requires ever-increasing amounts of raw material resources and at the same time bears the responsibility for the resulting waste. Waste is generated throughout the life cycle. In the initial phases it is referred to as industrial waste, while during construction, reconstruction, and demolition it is called construction waste. Construction waste is most voluminous but it also has a great potential in circular economy that aims at the closed loop cycle where already used construction materials and components are recovered as raw materials. Sustainable building principles include four basic strategies, waste avoidance, construction materials and components re-use, continued use, and recycling. The possibility of construction waste treatment and its possible recovery in the building process depends on the type of prevailing materials that are contained in building elements as well as on detachability, separability and inseparability of structural joints and components. The architect plays a responsible role in decreasing the volume of construction waste as the conception of a building represents the key factor in sustainable construction waste management. Planning a construction with a good dismantling potential at the end of the building’s life cycle includes a number of factors such as the choice of building materials with a low environmental impact, the design of detachable composite materials and structures as well as the design of mono material structures. This article focuses on waste resulting from the built environment and discusses architectural concepts with a potential of reducing the volume of construction waste and its potential recovery as a construction resource.

Sustainable Construction Materials

2016 ◽  
pp. 1-37
Author(s):  
R. V. Ralegaonkar ◽  
M. V. Madurwar ◽  
V. V. Sakhare
Keyword(s):  
Smart City ◽  
Raw Materials ◽  
Construction Materials ◽  
Raw Material ◽  
Sustainable Construction ◽  
City Development ◽  
Chemical Test ◽  
Physico Chemical ◽  
Increasing Demand ◽  
By Products

Due to ever increasing demand for the conventional construction materials as well as an increase in agro-industrial by-products it is essential to reuse these materials. As a smart city solution this chapter briefs an overview for the application of alternate raw materials as a principal source for the development of sustainable construction materials. The potential application of the discussed raw materials is elaborated as cementitious material, the aggregates as well as alternative reinforcement material. To understand the process of application, sustainable masonry product development is discussed in detail. In order to evaluate the feasibility of the raw material, the necessary physico-chemical test evaluation methods are also briefed. The developed end product performance evaluation is also discussed by desired tests as recommended by standards. The chapter concludes with a positive note that reuse of agro-industrial by-products is a feasible solution for the smart city development.

scholarly journals Parametric Studies Regarding the Development of Alkali-Activated Fly Ash-Based Geopolymer Concrete Using Romanian Local Raw Materials

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 11
Author(s):  
Adrian-Victor Lăzărescu ◽  
Henriette Szilagyi ◽  
Cornelia Baeră ◽  
Andreea Hegyi
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Negative Impact ◽  
Raw Materials ◽  
Geopolymer Concrete ◽  
Human Needs ◽  
Alternative Material ◽  
Parametric Studies ◽  
And Performance ◽  
Alkali Activated

Current research and development policies in the field of building materials, in the context of sustainable development, have the main objectives of increasing the safety and performance of the built environment at the same time as reducing pollution and its negative impact. Today, the idea that the sustainable city of the future should meet human needs and maintain a higher quality of life is worldwide unanimously accepted. The aim of this paper is to present results regarding the production of alkali-activated fly ash-based geopolymer concrete, a new, alternative material, produced using local available raw materials from Romania.

scholarly journals Fire-resistant cellulose boards from waste newspaper, boric acid salts and protein binders

2021 ◽  
Author(s):  
Paalo Moreno ◽  
Nicole Villamizar ◽  
Jefferson Perez ◽  
Angelica Bayona ◽  
Jesús Roman ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Boric Acid ◽  
Building Materials ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Sustainable Construction ◽  
Load Bearing ◽  
Protein Binders

Abstract Housing construction consumes more materials than any other economic activity, with a total of 40.6 Gt/year. Boards are placed between construction materials to serve as non-load-bearing partitions. Studies have been performed to find alternatives to conventional materials using recycled fibers, agro-industrial waste, and protein binders as raw materials. Here, fire-resistant cellulose boards with low density and adequate flexural strength were produced for use as non-load-bearing partitions using waste newspapers, soy protein, boric acid, and borax. A central composite design (CCD) was employed to study the influence of the board component percentage on flame retardancy (UL 94 horizontal burning test), density (ASTM D1037-12) and flexural strength (ISO 178–2010). The cellulose boards were characterized by thermal analysis (ASTM E1131-14) and scanning electron microscopy. Fire-resistant cellulose boards were successfully made with low densities (120–170 kg/m3) and flexural strength (0.06–0.64 MPa). The mechanical performance and fire resistance of cellulose boards suggest their suitability for use as building materials. A useful and sustainable construction material with great potential is produced with the valorization of waste materials.

scholarly journals Radiological and physico-chemical characterization of red mud as an Al-containing precursor in inorganic binders for the building industry

2021 ◽  
Vol 36 (2) ◽  
pp. 182-191
Author(s):  
Ljiljana Kljajevic ◽  
Miljana Mirkovic ◽  
Sabina Dolenec ◽  
Katarina Ster ◽  
Mustafa Hadzalic ◽  
...  
Keyword(s):  
Construction Industry ◽  
Natural Radioactivity ◽  
Red Mud ◽  
Building Materials ◽  
Raw Materials ◽  
Construction Materials ◽  
Polymerization Process ◽  
Alkali Activation ◽  
Silica Alumina ◽  
Alkali Activated

The potential re-use of red mud in the building and construction industry has been the subject of research of many scientists. The presented research is a contribution to the potential solution of this environmental issue through the synthesis of potential construction materials based on red mud. A promising way of recycling these secondary raw materials is the synthesis of alkali-activated binders or alkali activated materials. Alkali-activated materials or inorganic binders based on red mud are a new class of materials obtained by activation of inorganic precursors mainly constituted by silica, alumina and low content of calcium oxide. Since red mud contains radioactive elements like 226Ra and 232Th, this may be a problem for its further utilization. The content of naturally occurring radionuclides in manufactured material products with potential application in the building and construction industry is important from the standpoint of radiation protection. Gamma radiation of the primordial radionuclides, 40K and members of the uranium and thorium series, increases the external gamma dose rate. However, more and more precedence is being given to limiting the radiological dose originating from building materials on the population these days. The aim of this research was to investigate the possible influence of alkali activation-polymerization processes on the natural radioactivity of alkali activated materials synthesized by red mud (BOKSIT a. d. Milici, Zvornik, Bosnia and Herzegovina) and their structural properties. This research confirmed that during the polymerization process the natural radioactivity was reduced, and that the process of alkali activation of raw materials has an influence on natural radioactivity of synthesized materials.

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