scholarly journals Mechanical and Microstructural Properties of Ordinary Concrete with High Additions of Crushed Glass

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1872
Author(s):  
Cherif Belebchouche ◽  
Karim Moussaceb ◽  
Salah-Eddine Bensebti ◽  
Abdelkarim Aït-Mokhtar ◽  
Abdelkader Hammoudi ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Hardened Concrete ◽  
X Ray Diffraction ◽  
Glass Waste ◽  
Ordinary Concrete ◽  
Concrete Mix Design ◽  
Partial Cement Replacement ◽  
Mechanical And Microstructural Properties ◽  
Bet Technique ◽  
Mechanical Strengths

This study investigates the use of crushed glass waste as partial cement replacement in ordinary concretes. Six concrete mixes were designed and prepared: a reference without substitution and five substitution percentages of crushed glass waste ranging from 5% to 25%. The made concrete mix design underwent different tests, namely: slump test, mechanical strength, thermogravimetric analysis (TGA), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) determination and finally, water porosimetry, in order to evaluate the influence of the use of crushed glass waste on the properties of fresh and hardened concrete. Mechanical strengths results show that the use of 15% of the crushed glass waste improves the mechanical strength. TGA analysis confirms this result by highlighting a higher hydration degree. The latter contributes to the reduction of the porosity and, consequently, the mechanical strength increases. Also, it can be caused by the increasing amount of chromium which, if added a little, accelerates the hydration of C3S and leads to an increase of the mechanical strength. The BET technique and porosimetry tests showed that the use of crushed glass waste reduces the global porosity of concrete. This is due to the filling effect of the glass powder.

scholarly journals Effect of Different Mineralization Modes on Strengthening Calcareous Sand under Simulated Seawater Conditions

2021 ◽  
Vol 13 (15) ◽  
pp. 8265
Author(s):  
Shiyu Liu ◽  
Bowen Dong ◽  
Jin Yu ◽  
Yanyan Cai ◽  
Xingqian Peng ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Construction Projects ◽  
Construction Material ◽  
X Ray Diffraction ◽  
Calcareous Sand ◽  
Sand Column ◽  
Sporosarcina Pasteurii ◽  
Phosphate Mineralization ◽  
Filling Water ◽  
Simulated Seawater

Calcareous sand, as a blow-fill or construction material, is widely used in island and reef construction projects in marine environments after treatment. When microorganism-induced mineralization is used to strengthen calcareous sand, salinity and other conditions in the marine environment will adversely affect microorganisms or their mineralization process. For this reason, the two environmental conditions created by deionized water and simulated seawater were introduced to explore their effects on the growth and urease activity of Sporosarcina pasteurii. Then, the changes in the permeability and mechanical strength of calcareous sand under different mineralization methods were compared by one-dimensional sand column tests. Finally, the reinforcement mechanism was compared and analyzed based on the results of scanning electron microscopy and X-ray diffraction tests. The results show that Sporosarcina pasteurii can induce carbonate and phosphate precipitation and mineralization to strengthen calcareous sand in simulated seawater. The mineralized products greatly reduce the permeability of calcareous sand and significantly improve the mechanical strength by wrapping calcareous sand particles, filling water seepage channels and cementing adjacent particles. The reinforcement effect of carbonate mineralization is better than that of phosphate mineralization, but phosphate mineralization has less impact on the environment during the treatment process.

scholarly journals Enhancing carbonation and chloride resistance of autoclaved concrete by incorporating nano-CaCO3

2020 ◽  
Vol 9 (1) ◽  
pp. 998-1008
Author(s):  
Guo Li ◽  
Zheng Zhuang ◽  
Yajun Lv ◽  
Kejin Wang ◽  
David Hui
Keyword(s):  
Cement Hydration ◽  
Mercury Intrusion Porosimetry ◽  
Hardened Concrete ◽  
Optimal Dosage ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Carbonation Depth ◽  
X Ray ◽  
Chloride Resistance

AbstractThree nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.

scholarly journals Valorization of Brick and Glass CDWs for the Development of Geopolymers Containing More Than 80% of Wastes

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 672
Author(s):  
Dimitris Kioupis ◽  
Aggeliki Skaropoulou ◽  
Sotirios Tsivilis ◽  
Glikeria Kakali
Keyword(s):  
Electron Microscopy ◽  
Compressive Strength ◽  
Circular Economy ◽  
X Ray Diffraction ◽  
Glass Waste ◽  
X Ray ◽  
Optimum Synthesis ◽  
Synthesis Parameters ◽  
Construction And Demolition Wastes ◽  
Scanning Electron

One of the areas of priority in a circular economy, regarding waste management, regards the valorization of construction and demolition wastes (CDW). This study suggests the synthesis of geopolymeric binders based almost entirely on construction and demolition wastes. Ceramic waste was used as the aluminosilicate precursor of the geopolymer synthesis, while glass waste was applied in the preparation of the activation solution. A fractional experimental design defined the optimum synthesis parameters, based on compressive strength values. The final products were characterized by means of X-Ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The glass waste was appropriately processed in order to prepare the activation solution for the geopolymerization of brick waste. In this work, CDW-based geopolymers were produced with a compressive strength in the range 10–44 MPa. The developed products contained 80–90 wt.% CDWs, depending on the method of activator preparation.

Effect of Varying Wt% of TiC on Mechanical and Wear Properties of RZ5-TiC In-Situ Composite

2018 ◽  
Vol 8 (2) ◽  
pp. 45-56 ◽  
Author(s):  
Deepak Mehra ◽  
M.M. Mahapatra ◽  
S. P. Harsha
Keyword(s):  
Wear Resistance ◽  
Wear Behavior ◽  
Wear Test ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
X Ray ◽  
Tic Particle ◽  
Mechanical And Microstructural Properties ◽  
Sliding Distance

The purpose of this article is to enhance the mechanical properties and wear resistance of the RZ5 alloy used in the aerospace application by adding TiC particles. The present study discusses processing of in-situ RZ5-TiC composite fabricated by self-propagating high temperature (S.H.S.) method and its wear behavior. The effects of TiC particle on mechanical and microstructural properties of the composite are studied. The wear test is performed by varying the sliding distance and applied load. The composite is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results exhibited the properties like strength and hardness of RZ5-10wt%TiC composite has been increased considerably, while grain size is decreased as compared to the RZ5 alloy. The fractography indicated mixed mode (quasi-cleavage and ductile feature) failure of the composites. The wear results showed improvement in wear resistance of the composite. The FESEM showed dominate wear mechanisms are abrasion, ploughing grooves.

scholarly journals Theoretical Prediction of Mechanical Strength and Desalination Performance of One-Atom-Thick Hydrocarbon Polymer in Pressure-Driven Separation

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1358 ◽  
Author(s):  
Shuangqing Sun ◽  
Fei Shan ◽  
Qiang Lyu ◽  
Chunling Li ◽  
Songqing Hu
Keyword(s):  
Mechanical Strength ◽  
Simulation Method ◽  
Hydraulic Pressure ◽  
Gas Purification ◽  
Simulation Techniques ◽  
Separation Membrane ◽  
Hydrocarbon Polymers ◽  
Hydrocarbon Polymer ◽  
Mechanical Strengths ◽  
Pressure Driven

One-atom-thick materials hold promise for the future of membrane-based gas purification and water filtration applications. However, there are a few investigations on the mechanical properties of these materials under pressure-driven condition. Here, by employing molecular simulation techniques and continuum mechanics simulation, we investigate the mechanical strength of two-dimensional hydrocarbon polymers containing sub-nanometer pores with various topologies. We demonstrate that the mechanical strengths of the membranes are correlated with their pore sizes and geometries. In addition, when the pore size of substrates is controlled within a reasonable range, all of the membrane candidates can withstand the practical hydraulic pressure of few megapascal. The studied materials also exhibit better seawater desalination performance as compared to the traditional polymeric reverse osmosis membrane. This work presents a new route to design new separation membrane, and also propose a simulation method to evaluate the mechanical strength and desalination performance.

scholarly journals Evaluation of the Antibacterial Activity of a Geopolymer Mortar Based on Metakaolin Supplemented with TiO2 and CuO Particles Using Glass Waste as Fine Aggregate

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 157 ◽  
Author(s):  
Ruby Gutiérrez ◽  
Mónica Villaquirán-Caicedo ◽  
Sandra Ramírez-Benavides ◽  
Myriam Astudillo ◽  
Daniel Mejía
Keyword(s):  
Culture Media ◽  
Raw Materials ◽  
Silicate Solution ◽  
Fine Aggregate ◽  
X Ray Diffraction ◽  
Glass Waste ◽  
Homogeneous Surface ◽  
E Coli ◽  
Study Results ◽  
Antibacterial Surfaces

Metakaolin-based geopolymer cements were produced by alkaline activation with a potassium hydroxide and potassium silicate solution. To produce the geopolymer composites, 10 wt.% titanium oxide (TiO2) and 5 wt.% copper oxide (CuO) nanoparticles were used. The geopolymer mortar was prepared using glass waste as fine aggregate. The raw materials and materials produced were characterized by X-ray diffraction, electron microscopy, and Fourier-transform infrared spectroscopy techniques. Likewise, the geopolymer samples were characterized to determine their physical properties, including their density, porosity, and absorption. The photocatalytic activity of the materials was evaluated by activating the nanoparticles in a chamber with UV–Vis light during 24 h; then, different tests were performed to determine the growth inhibition of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa bacteria in nutrient agar for times of up to 24 h. The study results showed that a geopolymer mortar containing glass waste as fine aggregate (GP-G) exhibited a water absorption 56.73% lower than that of the reference geopolymer paste without glass (GP). Likewise, glass particles allowed the material to have a smoother and more homogeneous surface. The pore volume and density of the GP-G were 37.97% lower and 40.36% higher, respectively, than those of the GP. The study with bacteria showed that, after 24 h in the culture media, the GP-G mortars exhibited a high inhibition capacity for the growth of P. aeruginosa from solutions of 10−4 mL and in solutions of 10−6 mL for E. coli and S. aureus. These results indicate the possibility of generating antibacterial surfaces by applying geopolymer composite.

Identification and enhancement of the thermal and mechanical properties of two types of plasters successively derived from gypsum: from the Safi basin and the High Atlas of Marrakech, Morocco

2020 ◽  
Author(s):  
imane baba ◽  
Mounsif Ibnoussina ◽  
Omar Witam
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Mechanical Strength ◽  
Setting Time ◽  
Density Measurement ◽  
Raw Material ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
X Ray Diffraction ◽  
High Atlas

<p>Over the past few decades, the construction industry has focused on sustainable, environmentally friendly and easily recyclable materials. The objective of this work is to characterize and enhance the thermal conductivity, mechanical strength and setting time of a composite material based on plaster and lime. This material is designed for use in plasters.</p><p>Two types of gypsum are studied, the first one belongs to the Safi basin, the second one characterizes the High Atlas of Marrakech and precisely Douar Tafza. Geologically speaking, the two sites have many similarities. They are characterized by a Meso-Cenozoic age coverage covering a deformed Paleozoic age basement.</p><p>The characterization of the plaster's raw material, gypsum, was necessary to determine its physical and geotechnical properties, mineralogy, thermal behaviour and microscopic structure. Several analyses have been developed such as: pycnometer density measurement, X-ray diffraction, infrared spectroscopy and scanning electron microscopy.</p><p>We made samples, of standardized dimensions, of two mixtures based on the two types of plaster reinforced by the addition of two types of lime from different localities. The latter are from Marrakech and the Agadir region. The water/plaster mass ratio was set at 0.75 and the addition of lime was achieved by increasing its percentage in slices by 12.5% and up to 50%.</p><p>The reinforcement of plaster with lime has enhanced its thermal and mechanical properties and setting time. The measurements show that the addition of lime has reduced the thermal conductivity and increased the mechanical strength of both types of plaster. In addition, following the addition of lime, the setting time has decreased and the basicity of the material has increased. Noting that the intrinsic properties of the raw material influence the mechanical and thermal properties of the material.</p><p><strong>Keywords:</strong>   plaster, enhancement, properties, mechanical, thermal, Morocco</p>

Fabrication and Characterization of Alumina/Zirconia Ceramic Compound

2012 ◽  
Vol 724 ◽  
pp. 249-254 ◽  
Author(s):  
Bum Rae Cho ◽  
Ji Hoon Chae ◽  
Bo Lang Kim ◽  
Jong Bong Kang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Low Temperature ◽  
Mechanical Strength ◽  
Sem Analysis ◽  
Zirconia Ceramic ◽  
Sintering Process ◽  
Sintering Aids ◽  
X Ray Diffraction

Sintered ZTA(zirconia toughened alumina) which has good mechanical properties at a low temperature was produced by milling and mixing with Al2O3 and ZrO2(3Y-TZP). In order to examine the effect of sintering aids on the mechanical properties of ZTA, fracture toughness and hardness of the produced ZTA were observed in accordance with change of the added quantity of ZrO2 Scanning electron microscopy and X-ray diffraction technique were applied to observe microstructural change and phase transformation during the process. Experimental results showed that the addition of sintering aids in ZTA at a low temperature induced densification and adding SiO2 and talc lowered sintering temperature and promoted crystallization process of the compound. The mechanical strength of ZTA added ZrO2 showed higher mechanical strength and SEM analysis revealed that Al2O3 and ZrO2 during the sintering process restrained the grain growth each other. Especially, the 92% Al2O3 added sintering aids showed more than 98% of the theoretical density and more than 1500 Hv of hardness value at a low temperature of 1400. It was also showed that the fracture toughness is gradually increasing first and decreasing later in accordance with the quantity of ZrO2.

scholarly journals Investigation on Structural and Optical Properties of Willemite Doped Mn2+Based Glass-Ceramics Prepared by Conventional Solid-State Method

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Nur Farhana Samsudin ◽  
Khamirul Amin Matori ◽  
Josephine Ying Chi Liew ◽  
Yap Wing Fen ◽  
Mohd Hafiz Mohd Zaid ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Glass Ceramics ◽  
Structural Evolution ◽  
Emission Spectra ◽  
Soda Lime ◽  
X Ray Diffraction ◽  
Glass Waste ◽  
Solid State Method ◽  
Ceramic Samples ◽  
Zno Crystal

Mn-doped willemite (Zn2SiO4:Mn2+) glass-ceramics derived from ZnO-SLS glass system were prepared by a conventional melt-quenching technique followed by a controlled crystallization step employing the heat treatment process. Soda lime silica (SLS) glass waste, ZnO, and MnO were used as sources of silicon, zinc, and manganese, respectively. The obtained glass-ceramic samples were characterized using the X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared (FTIR), UV-Visible (UV-Vis), and photoluminescence (PL) spectroscopy. The results of XRD revealed that ZnO crystal and willemite (β-Zn2SiO4) were presented as major embedded crystalline phases. This observation was consistent with the result of FESEM which showed the presence of irregularity in shape and size of willemite crystallites. FTIR spectroscopy exhibits the structural evolution of willemite based glass-ceramics. The optical band gap shows a decreasing trend as the Mn-doping content increased. Photoluminescent technique was applied to characterize the role of Mn2+ions when entering the willemite glass-ceramic structure. By measuring the excitation and emission spectra, the main emission peak of the glass-ceramic samples located at a wavelength of 585 nm after subjecting to 260 nm excitations. The following results indicate that the obtained glass-ceramics can be applied as phosphor materials.

scholarly journals The relationship between microstructure and mechanical properties of directly bonded copper-alumina ceramics joints

2014 ◽  
Vol 62 (1) ◽  
pp. 23-32 ◽  
Author(s):  
K. Pietrzak ◽  
W. Olesinska ◽  
D. Kalinski ◽  
A. Strojny-Nedza
Keyword(s):  
Mechanical Strength ◽  
Transition Layer ◽  
Diffraction Method ◽  
Alumina Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Three Point Bending ◽  
Microscopy Method ◽  
Materials Used ◽  
The Individual

Abstract The effect of phase transformations induced in the surface layer of alumina ceramics during its direct joining with copper activated with oxygen or titanium on the mechanical strength of the ceramic/copper joints was examined. The materials used in the experiments were an alumina single crystal, alumina ceramics (97.5 wt% Al2O3), the cermet mixtures: Cu-Cu2O with 10-50 wt% of Cu2O, copper with 5 wt% of Ti, and copper with 5 wt% of Ti and 10 wt% of Ag. The microstructure of the transition layer was examined by the X-ray diffraction method (XRD), scanning electron microscopy method (SEM) and energy dispersive x-ray spectroscopy (EDX). The mechanical strength of the joints was measured using the three-point bending method. The amount of oxygen optimal for the joining process was determined. It has been demonstrated that the cohesion of the joints depends not only on the formation of the individual phases but also, or even primarily, on the microstructure of the transition layer formed between them.

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