scholarly journals Recycling Construction and Demolition Residues in Clay Bricks

2021 ◽  
Vol 11 (19) ◽  
pp. 8918
Author(s):  
Chiara Zanelli ◽  
Elena Marrocchino ◽  
Guia Guarini ◽  
Alice Toffano ◽  
Carmela Vaccaro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Environmental Impact ◽  
Construction Industry ◽  
Mineralogical Composition ◽  
Processing Plant ◽  
Fine Grained ◽  
Technical Performance ◽  
Clay Bricks ◽  
Compositional Properties

In recent years, the management of construction and demolition residues (CDRs) has become a major challenge for the construction industry due to the increasing volume of waste produced and its associated environmental impact. The aim of this article is to assess the effect of fine-grained fractions (<0.125 mm–0.6–0.125 mm) of construction and demolition residues, obtained by industrial sorting in a CDR processing plant in Rovigo (Italy), on the technological behavior and technical performance of clay bricks. Simulating the brickmaking process on a laboratory scale, it was appraised whether the CDR additions determined any change in the main properties of both fired and unfired bricks, taking a CDR-free brick body as a reference. The results indicated that the use of CDR is technologically feasible. It is possible to obtain, through proper crushing and sorting operations, grain-sized fractions with quite homogenous chemical and mineralogical composition. The residues did affect the compositional properties, porosity and water absorption of the clay bricks. Nevertheless, the characterization of the residual-added semi-finished and fired products highlighted their good technological and mechanical properties, which allowed them to provide performances similar to those of standard bricks manufactured with raw natural materials.

scholarly journals Microstructural and Mechanical Characterization of Multilayered Iron Electrodeposits

2011 ◽  
Vol 409 ◽  
pp. 474-479 ◽  
Author(s):  
C. Chan ◽  
J.L. McCrea ◽  
G. Palumbo ◽  
Uwe Erb
Keyword(s):  
Mechanical Properties ◽  
Columnar Structure ◽  
Multilayered Structure ◽  
Structure Design ◽  
Coarse Grained ◽  
Fine Grained ◽  
Microstructure And Mechanical Properties ◽  
Fine Grained Structure ◽  
Iron Coatings

Monolithic and multilayered iron electrodeposits were successfully synthesized by the pulse plating electrodeposition method. Electron microscopy and Vickers microhardness measurements were used to investigate the microstructure and mechanical properties of the iron electrodeposits produced. Two types of monolithic iron coatings were produced, one with a coarse grained, columnar structure and the other with an ultra-fine grained structure. Hall-Petch type grain size strengthening was observed in these monolithic coatings. Multilayered iron coatings composed of alternating layers of coarse grained and fine grained structures were also produced. The hardness value of the multilayered coatings falls between the hardness values for the two types of monolithic coatings produced. This study has demonstrated the possibility of applying a multilayered structure design to tailor the microstructure and mechanical properties of electrodeposited iron coatings.

Medium-Fraction Materials for Processing of Coal-Thread Waste Drains for the Production of Wall Ceramics

2018 ◽  
Vol 931 ◽  
pp. 532-536 ◽  
Author(s):  
Khungianos S. Yavruyan ◽  
Vladimir D. Kotlyar ◽  
Evgeny S. Gaishun
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Fractional Composition ◽  
Mineralogical Composition ◽  
General Characteristic ◽  
Technological Properties ◽  
Petrographic Composition ◽  
Fine Grained ◽  
Polyfunctional Additive ◽  
Preliminary Classification

The general characteristic of products of processing of waste heaps is given. Their characteristics by fractional composition are proposed: large-fractional, with grains from 2 to 150 mm in size, medium-fractional with a grain size of 0.5 to 2 mm, and fine-grained with a grain size of 0 to 0.5 mm. The results of work on the study of the chemical-mineralogical composition and physico-mechanical properties of the medium-fractionation products of the waste heaps processing with reference to the production of various wall ceramics products are presented. Their role is shown as a polyfunctional additive when introduced into ceramic masses and affects the properties of finished products. A preliminary classification according to the amount of coal component, mineralogical and petrographic composition, technological properties is proposed. The feasibility of their application in the production of wall ceramics with a reduced cost is given.

scholarly journals Manufacturing of Bricks From Coal Mine Overburden Dump of Korba, Chhattisgarh, India

2020 ◽  
Author(s):  
Shailendra Kumar Singh ◽  
Ranjeet K Singh
Keyword(s):  
Mechanical Properties ◽  
Sodium Silicate ◽  
Coal Mine ◽  
Value Added ◽  
Loss On Ignition ◽  
Process Technology ◽  
Clay Bricks ◽  
Standardized Parameters ◽  
Value Added Products

Abstract Mixing coal mine overburden with sodium silicate and cement, for manufacturing bricks was studied with the objective of converting the coal mine overburden waste into value-added products. Bricks were prepared using different compositions of coal mine overburden with proportions of sodium silicate and Ordinary Portland Cement (OPC), in cuboid mould (9″ X 5″X 3″). Bricks were air dried for 24 hours, placed in oven for 115 ± 10 °C for 24 hours. Characterization of tailings and manufactured bricks were done. Mechanical properties such as compressive strength (CS), water absorption (WA), loss on ignition (LoI) and efflorescence were measured. The maximum CS of 9.5 N/mm2 was recorded for brick having overburden to cement ratio of 8:2. However, for making it more economical the ratio of 9:1 was considered and this compares very well cost with full filed the Indian standard (IS): 3495 (Part 1) (1992) of bricks. The results also indicated that the overburden percentage in the bricks affect their mechanical properties. The WA rates of the manufactured bricks are low compared to standard conventional clay bricks, and the same varies with process parameters. The low capillary pore may deter the formation of efflorescence. The process, with standardized parameters, may be commercially adapted, and large quantities of coal mine overburden may be put to use in making bricks. Thus, the process technology observed in this paper can potentially convert the huge amount of environmentally hazardous waste into value added product. Coal mine overburden may materialize as a sustainable supplement to conventional clay, use of which in brick making is totally restricted. The finding also usher a new area of research.

Microstructure Characterization of Tungsten Based Alloys for Fusion Application

2013 ◽  
Vol 58 (2) ◽  
pp. 473-476 ◽  
Author(s):  
G. Cempura ◽  
A. Kruk ◽  
C. Thomser ◽  
M. Wirtz ◽  
A. Czyrska-Filemonowicz
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Electron Tomography ◽  
Analytical Electron Microscopy ◽  
Large Scatter ◽  
Fine Grained ◽  
Analytical Electron ◽  
The Matrix ◽  
Strengthening Particles

The microstructure of two tungsten based alloys (W-1.1%TiC and W-1.7% TiC) was characterized using light microscopy, analytical electron microscopy and electron tomography. These alloys represent a class of W based dispersion strengthened alloys with TiC used as strengthening particles. Addition of TiC leads to improved creep resistance and tensile strength of the W based alloys. The results show that the W-1.7%TiC alloy exhibits large scatter in grain size, much higher porosity and contains also Ti-O particles. The W-1.1%TiC alloy has fine grained microstructure with uniformly distributed fine TiC particles within the matrix and low porosity. As a result of the different microstructure, the W-1.1%TiC alloy exhibits better mechanical properties, when compared to the W-1.7%TiC alloy.

Geomechanical Characterization of Faulted Rock Materials in Korea

2006 ◽  
Vol 321-323 ◽  
pp. 328-331 ◽  
Author(s):  
Yong Seok Seo ◽  
Chang Yong Kim ◽  
Kwang Yeom Kim ◽  
Kyoung Mi Lee
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Physical And Mechanical Properties ◽  
Mineralogical Composition ◽  
Rock Materials ◽  
Direct Shear Tests ◽  
Fault Gouges ◽  
Geomechanical Characterization ◽  
Mineralogical Assemblage

A faulted rock usually shows the swelling behavior because of clay minerals which consist of the fault gouges. It makes rock mass unstable and threatens the safety of structures built in rock mass. This study was aimed at clarifying characteristics of physical and mechanical properties of faulted rock materials. At first, microstructures and mineralogical composition associated with faulting in the fault gouge zones were analyzed by using X-ray diffractometry (XRD) and SEM microphotographs. Physical properties of the faulted rock materials from fields were measured in the laboratory. It is well known that the mechanical properties are sensitive to the mineralogical assemblage and are affected by the shapes, distribution and preferred crystallographic orientation of the components. Material and direct shear tests were also conducted on faulted rock materials under saturated and unsaturated conditions. The mechanical results were analyzed together with the analyzed result of XRD and SEM.

IMPACTOS AMBIENTAIS CAUSADOS POR ATIVIDADE DE MINERAÇÃO DE AREIA EM DUNAS FIXAS, CAUCAIA, CEARÁ

2019 ◽  
Vol 21 (2) ◽  
pp. 1060-1069
Author(s):  
Letícia De Freitas Vieira ◽  
Antonio Jeovah De Andrade Meireles ◽  
Henrique Sampaio De Castro
Keyword(s):  
Environmental Impact ◽  
Construction Industry ◽  
Interaction Matrix ◽  
Office Work ◽  
Check List ◽  
Landscape Characterization ◽  
High Magnitude ◽  
Negative Impacts

Este trabalho propõe-se em trazer uma discussão acerca da mineração, enfocando nos impactos ambientais causados pela extração de agregados para a construção civil. A área de estudo é uma poligonal de 44,8 hectares, licenciada para extrair areia até 2018. Localizada em uma duna fixa, foi possível constatar os impactos relacionados com o desmatamento, retirada do solo e do minério, mudança topográfica e o afloramento do lençol freático. A metodologia consistiu em trabalho de campo, gabinete e aplicações de métodos da Avaliação de Impactos Ambientais que foram a Metodologia de listagem (Check-list) e Matrizes de interações. Através dessas metodologias, alguns dos resultados obtidos foram a descaracterização da paisagem, a determinação dos processos evolutivos do campo de dunas com a extração mineral e o afloramento do lençol freático. Por meio do check-list, foram elencados os impactos positivos e negativos, e a matriz de interações relacionou os impactos do empreendimento com o meio ambiente. Baseado nos resultados, concluiu-se que os impactos da mineração são 44% negativos e apenas 6% positivos e que, na maioria dos casos, o impacto ambiental foi de elevada magnitude, representando atividade nitidamente insustentável no âmbito social e ambiental.Palavras-chave: Mineração; Descaracterização da paisagem; Impacto ambiental. ABSTRACTThe present work proposes a discussion about mining, with emphasis on the environmental impacts caused by the extraction of aggregates for the construction industry. The study area is a 44.8 hectare polygon that was auctioned for sand extraction until 2018. Located on a fixed dune, Related to: deforestation, removal of vegetation, soil and ore, topographic change and outcropping of groundwater . The methodology consisted of fieldwork, office work and the applications Environmental Impact Assessment Methods that were the List Methodology (Checklist) and Interaction Matrices. Through these methodologies, some of the results obtained were the de-characterization of the landscape,The determination of the evolutionary processes of the dune field with the mineral extraction and the outcrop of the water table Positive and negative impacts were listed throughout the checklist and the interaction matrix related to development impacts within the environment. Based on the results, it was concluded that the impacts of mining are 44% negative and only 6% positive and that in most cases, the environmental impact was of high magnitude, representing a clearly unsustainable social and environmental activity.Keywords: Mining; Landscape characterization; Environmental impact.

Characterization of the mechanical properties of ultra-fine grained NiTiCr-wires

2009 ◽  
Vol 40 (1-2) ◽  
pp. 17-22 ◽  
Author(s):  
M. Frotscher ◽  
J. Burow ◽  
P. Schön ◽  
K. Neuking ◽  
R. Böckmann ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fine Grained

scholarly journals Determinación de las propiedades térmicas de un mortero modificado con sargazo como material alternativo en construcción

2019 ◽  
pp. 1-9
Author(s):  
Alberto Zavala-Arceo ◽  
Julio César Cruz-Argüello ◽  
Mayra Zyzlila Figueroa-Torres ◽  
Alberto Yeladaqui-Tello
Keyword(s):  
Mechanical Properties ◽  
Construction Industry ◽  
Thermal Load ◽  
Thermal Transfer ◽  
Hardening Process ◽  
Sustainable Materials ◽  
Compression Resistance ◽  
Resistance Tests ◽  
Reducing Energy

In the present work we analyze the properties of a mortar with the addition of treated sargassum algae, replacing the stone aggregate in percentages of 5%, 10%, 15% and 20% in order to reduce the thermal conductivity of the coating and the thermal load of the interior of the buildings, thus reducing energy consumption and implementing sustainable materials to the construction industry. For the purposes of this investigation, a characterization of the components of the mortar was carried out, the stone aggregate and the sargassum treated for its use as an aggregate. Samples were prepared for each percentage and compression resistance tests were performed at 3, 7, 14 and 28 days to analyze the behavior of the mortar during the hardening process. Adhesion tests were performed to determine if the mixtures are efficient for use as a coating. Subsequently, the thermal transfer was evaluated by conduction and convection. The material showed hydrophilic characteristics, therefore, the analysis of the mechanical properties showed as bigger substitution of sargassum, low is the resistance, limiting the efficient percentages to 5 and 10% for its use.

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

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