Lightweight Concrete Manufacturing Technology Based on Waste Energy Raw Materials Alkaline-Activated

2020 ◽  
Vol 847 ◽  
pp. 155-160
Author(s):  
Marta Nalewajko

This article focuses on the compression strength of lightweight concrete based on alkaline-activated waste materials. The problem is important not only because of the possibility of disposal of excessive amount of building or industrial waste, but also because of the decreasing amount of natural aggregate deposits. Apart from the problem of the decreasing amount of natural aggregate deposits, there is also a problem related to the emission of greenhouse gases from cement production processes. It is estimated that the synthesis of alkaline-activated composites is twice as energy-intensive as the production of Portland cement and generates 4-8 times less carbon dioxide. Alkaline-activated concrete production can therefore lead to a significant reduction in environmental impact. The paper presents a thesis that there is a possibility of a monolithic combination of an alkaline activated mineral binder with an artificial ash-porbit aggregate, which will contribute to the improvement of the compression strength of light concrete based on alkaline activated energy waste materials and elimination of Portland cements.

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2289 ◽  
Author(s):  
Jacek Halbiniak ◽  
Jacek Katzer ◽  
Maciej Major ◽  
Izabela Major

Many byproducts and waste materials with pozzolanic properties can substitute natural raw materials in cement production. Some of these waste materials like fly ash and blast furnace slag are commonly harnessed by cement industry. Others are of seldom use due to limitations of the very centralized cement production systems currently in use. In the authors opinion, it is necessary to change this system to enable efficient utilization of various waste materials that are available locally (e.g., white and red ceramics). In this study, a new partially centralized system of cement production is proposed. The adoption of a new system would significantly reduce the volume of long-distance transportation and enable utilization of numerous locally available waste materials that are currently dismissed. The last stage of production of the ready-to-use cement would take place in situ. The cement would be produced on demand and be immediately used for concrete production on-site. The research program was conducted considering the importance of the quality of cements obtained in the new way, substituting up to 12% of its mass by white ceramics. The research program was proof of concept of the proposed cement production system. It was shown that the quality of “in situ cement” does not differ from standard cements.


2021 ◽  
Vol 876 ◽  
pp. 83-87
Author(s):  
Anthony N. Ede ◽  
Praise O. Gideon ◽  
Akpabot I. Akpabot ◽  
Solomon O. Oyebisi ◽  
Oluwarotimi Michael Olofinnade ◽  
...  

As the world population continues to increase, so does the demand for raw materials to produce basic needs of the human race. One of the areas where this pressing demand for means of production is evident is in the production of concrete materials for building construction and infrastructure. The source of constitutive materials for concrete production, such as cement and aggregates are fast shrinking across the nations of the earth, and there is an urgent need for substitutes that will guarantee the availability of this essential material to the built environment sector of the economy. One of the trending approaches is the adoption of waste materials as a replacement for some of the constitutive materials of concrete. This research reviews past works on the use of recycled plastic waste and periwinkle shells for the production of lightweight aggregate concrete. The results of this review showed that the adoption of a reduced percentage of waste plastic in concrete leads to acceptable strengths for lightweight concrete, economy, efficient energy and excellent crack resistance. The use of periwinkle shell is beneficial for satisfactory strengths for normal aggregate concrete and for lightweight aggregate concrete, excellent resistance to heat and economy. This approach is sustainable as a means of recycling and will facilitate the actualization of the sustainable development goal “Responsible Production and Consumption”, (SDGs 12). There is a perspective that combining these two waste materials will lead to improvement towards achieving sustainable concrete.


2019 ◽  
Vol 11 (7) ◽  
pp. 1876 ◽  
Author(s):  
Carlos Parra ◽  
Eva M. Sánchez ◽  
Isabel Miñano ◽  
Francisco Benito ◽  
Pilar Hidalgo

The use of waste materials as lightweight aggregates in concrete is highly recommended in seismic risk areas and environmentally recommended. However, reaching the strength needed for the concrete to be used structurally may be challenging. In this study four dosages were assayed: the first two-specimen had high cement content (550 and 700 kg/m3 respectively), Nanosilica, fly ash and superplasticizer. These samples were high performance, reaching a strength of 100MPa at 90 days. The other two mixtures were identical but replaced 48% of the aggregates with recycled lightweight aggregates (30% polypropylene, 18.5% cork). To estimate its strength and durability the mixtures were subjected to several tests. Compression strength, elasticity modulus, mercury intrusion porosimetry, carbonation, attack by chlorides, and penetration of water under pressure were analyzed. The compression strength and density of the lightweight mixtures were reduced 68% and 19% respectively; nonetheless, both retained valid levels for structural use (over 30MPa at 90 days). Results, such as the total porosity between 9.83% and 17.75% or the chloride ion penetration between 8.6 and 5.9mm, suggest that the durability of these concretes, including the lightweight ones, is bound to be very high thanks to a very low porosity and high resistance to chemical attacks.


2020 ◽  
Vol 12 (23) ◽  
pp. 9873
Author(s):  
Vojtěch Václavík ◽  
Marcela Ondová ◽  
Tomáš Dvorský ◽  
Adriana Eštoková ◽  
Martina Fabiánová ◽  
...  

Sustainability in the construction industry refers to all resource-efficient and environmentally responsible processes throughout the life cycle of a structure. Green buildings may incorporate reused, recycled, or recovered materials in their construction. Concrete is as an important building material. Due to the implementation of by-products and waste from various industries into its structure, concrete represents a significant sustainable material. Steel slag has great potential for its reuse in concrete production. Despite its volume changes over time, steel slag can be applied in concrete as a cement replacement (normally) or as a substitute for natural aggregates (rarely). This paper focused on an investigation of concrete with steel slag as a substitute of natural gravel aggregate. Testing physical and mechanical properties of nontraditional concrete with steel slag as a substitute for natural aggregates of 4/8 mm and 8/16 mm fractions confirmed the possibility of using slag as a partial replacement of natural aggregate. Several samples of concrete with steel slag achieved even better mechanical parameters (e.g., compressive strength, frost resistance) than samples with natural aggregate. Moreover, a life cycle assessment (LCA) was performed within the system boundaries cradle-to-gate. The LCA results showed that replacements of natural aggregates significantly affected the utilization rate of nonrenewable raw materials and reduced the overall negative impacts of concrete on the environment up to 7%. The sustainability indicators (SUI), which considered the LCA data together with the technical parameters of concrete, were set to evaluate sustainability of the analyzed concretes. Based on the SUI results, replacing only one fraction of natural gravel aggregate in concrete was a more sustainable solution than replacing both fractions at once. These results confirmed the benefits of using waste to produce sustainable materials in construction industry.


2016 ◽  
Vol 47 (4) ◽  
pp. 1600
Author(s):  
I. Anagnostopoulos ◽  
P. Lampropoulou ◽  
Th. Tzevelekou ◽  
V. Stivanakis ◽  
A. Kastanaki ◽  
...  

The production of lightweight aggregates from the utilization of solid byproducts [fly ash (FA) and bottom ash (BA)], of the lignite fired power plants from West Macedonia (Kardia, Ptolemaida) and Peloponnesus (Megalopolis), has been investigated in this study. Sintering of FA and BA with the grate sinter band method was selected because it exploits the energy content of the raw materials for the increase of temperature and completion of the material’s sintering. These byproducts contain the necessary carbon content for temperature increase during the sintering process. Detailed XRD analyses show that Megalopoli’s FA contains high amounts of amorphous phase (25-54wt%) while fly ashes from Kardia and Ptolemaida power units are more crystalline. Lime and anhydrite are the most abundant crystalline phases in Ptolemaida’s and Kardia’s fly ashes. The bottom ashes revealed high percentages of amorphous content (58-64wt%) and anorthite and quartz as the major crystalline phases. Mixtures of different BA/FA ratios were prepared for sintering tests. The sintered mixtures from Kardia’s and Ptolemaida’s regions did not have sufficient mechanical properties for further treatment. The sintercake produced from Megalopolis’ ashes exhibited good mechanical properties and was selected for further study for use as light aggregate raw materials to the lightweight concrete production.


2017 ◽  
Vol 17 (1) ◽  
pp. 83
Author(s):  
Nur Fatoni ◽  
Rinaldy Imanuddin ◽  
Ahmad Ridho Darmawan

Waste management is still defined as limited to collection, transportation and garbage disposal. The follow-up of the meaning is the provision of facilities such as garbage bins, garbage trucks and waste collection land. Waste management has not included waste separation. Segregation of waste can minimize the amount of waste that must be discharged to the final place. Segregation of waste can supply recyclable raw materials and handicrafts made from garbage. The manufacture of handicraft products from garbage is still local and requires socialization and training. It is needed to increase the number of craftsmen and garbage absorption on the crafters. Through careful socialization and training, citizens' awareness of waste management becomes advanced by making handicrafts of economic value from waste materials.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 439
Author(s):  
Sandra Filipović ◽  
Olivera Đokić ◽  
Aleksandar Radević ◽  
Dimitrije Zakić

Copper slag, a by-product of the pyrometallurgical process used for obtaining copper from copper ore in Bor, Serbia, contains mainly silicon, iron, calcium, and aluminium oxides. Due to such properties, it is disposed of in landfills. Despite the favourable technical properties copper slag aggregates possess, such as low-water absorption (WA24 0.6%), low resistance to fragmentation (LA 10%), and low resistance to wear (MDE 4%), its use in the construction industry is still limited. The results of testing the technical properties of copper slag aggregates (CSAs) as a potential replacement for natural river aggregate (RA) are presented in this paper. The experiments included tests on three concrete mixtures with partial replacement of coarse natural aggregate with copper slag. The replacement of RA particle sizes of 8/16 mm and 16/31.5 mm with CSA in the amount of 20% + 50% and 50% + 50% resulted in an increase in the compressive strength of 12.4% and 10.5%, respectively. The increase of CSA content led to a decrease in water penetration resistance and salt-frost resistance of concrete, whereas the resistance to chloride ion penetration did not change significantly.


2016 ◽  
Vol 881 ◽  
pp. 346-350 ◽  
Author(s):  
Luzana Leite Brasileiro ◽  
Fátima Maria de Souza Pereira ◽  
Pablo de Abreu Vieira ◽  
José Milton Elias de Matos

Every year, there is a considerable increase in the exploitation of deposits to supply the market for aggregates. On the other hand, so does the production of solid waste from construction and demolition waste (CDW). In 2010 Brazil approved the PNRS (National Policy on Solid Waste), which sets out how the country should have their waste, encouraging recycling and sustainability. As an alternative to the above problem, this paper aims to investigate the feasibility of partial and total replacement of the asphalt concrete aggregates by recycled aggregates from CDW in order to reduce the environmental impacts caused by the operation of quarries and give an adequate final destination the residue produced by man in construction. Were carried out five (05) projects mixture of: the first (parameter of our research) used only natural aggregates (0% CDW) in the second, third and fourth replaced 25%, 50% and 75% respectively of natural aggregate by the recycled aggregate and the fifth and last, used only recycled aggregates (100% CDW). They carried out the characterization of the aggregates by means of physico-chemical and mechanical, analyzing them with reference based on specific standards paving. For mixtures, they calculated the volumetric parameters and performed mechanical tests of tensile strength and stability. The results indicate that the recycled aggregate, in a defined proportion, can replace the natural aggregate in the flexible pavements


2021 ◽  
Vol 320 ◽  
pp. 181-185
Author(s):  
Elvija Namsone ◽  
Genadijs Sahmenko ◽  
Irina Shvetsova ◽  
Aleksandrs Korjakins

Because of low calcination temperature, magnesia binders are attributed as low-CO2 emission materials that can benefit the environment by reducing the energy consumption of building sector. Portland cement in different areas of construction can be replaced by magnesia binder which do not require autoclave treatment for hardening, it has low thermal conductivity and high strength properties. Magnesium-based materials are characterized by decorativeness and ecological compatibility.The experimental part of this research is based on the preparation of magnesia binders by adding raw materials and calcinated products and caustic magnesia. The aim of this study was to obtain low-CO2 emission and eco-friendly material using local dolomite waste materials, comparing physical, mechanical, thermal properties of magnesium binders.


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