scholarly journals Assessment of the pozzolanic activity of ornamental stone waste after heat treatment and its effect on the mechanical properties of concretes

2018 ◽  
Vol 11 (6) ◽  
pp. 1186-1207 ◽  
Author(s):  
S. H. M. MITTRI ◽  
M. K. DEGEN ◽  
G. L. VIEIRA ◽  
J. S. VAZZOLER ◽  
L. H. C. H. RODRIGUES
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Portland Cement ◽  
Mechanical Strength ◽  
Physical Characteristics ◽  
Pozzolanic Activity ◽  
Processing Waste ◽  
Ornamental Stone ◽  
Pozzolanic Materials ◽  
Pozzolanic Properties

Abstract This paper aims at evaluating the pozzolanic properties of ornamental stone processing waste after heat treatment at 1200 °C (HTOSPW) and analyzing the influence on the mechanical strength of concrete produced with HTOSPW addition at the contents of 5% and 10% by mass of Portland cement. The HTOSPW shows promising results regarding the pozzolanic activity, revealing chemical and physical characteristics typical of pozzolanic materials in addition to being approved in the pozzolanicity tests performed. As for the concretes produced with HTOSPW addition, a significant increase in mechanical strength was observed, especially for concretes with a 10% addition.

scholarly journals Use of clay from a local source for calcination and subsequent preparation of the mixed cement

2021 ◽  
Vol 1205 (1) ◽  
pp. 012005
Author(s):  
B Smirova ◽  
M Sedlacik ◽  
R Novotny
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Mechanical Strength ◽  
Cementitious Materials ◽  
Pozzolanic Activity ◽  
Supplementary Cementitious Materials ◽  
Hydration Process ◽  
Local Source ◽  
Optimal Ratio ◽  
Initial Decrease

Abstract This paper deals with the use of calcinated clay and micronized limestone as supplementary cementitious materials (SMCs) for preparation of blended Portland cement CEM II/B-M (Q-LL). Clay used in this study was calcinated at 700°C and pozzolanic activity after calcination was assessed using accelerated R3 pozzolanic test and modified Chapelle test. The influence of calcinated clay and limestone addition on mechanical properties and hydration process was investigated and an optimal ratio for 35% clinker replacement was found. Initial decrease of mechanical strength at early ages, caused by SCM addition, was almost compensated during maturation of the binder.

scholarly journals Influence of wire arc additive manufacturing of Ti-6Al-4V on microstructure and mechanical properties for potential large-scale aviation parts

2020 ◽  
Vol 321 ◽  
pp. 03037
Author(s):  
D. Elitzer ◽  
H.W. Höppel ◽  
M. Göken ◽  
D. Baier ◽  
C. Fuchs ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Additive Manufacturing ◽  
Mechanical Strength ◽  
Large Scale ◽  
Solution Treatment ◽  
Compression Tests ◽  
Process Gas ◽  
Relationship Of ◽  
Wire Arc Additive Manufacturing

As one of the most common Titanium alloys, Ti-6Al-4V faces new challenges concerning the ecological footprint. Due to the current processes, a high metal chip pollution leads to a Buy-to-Fly of 25:1. In this study the parameter / microstructure relationship of Ti-64 on the mechanical properties are discussed. Wire Arc Additive Manufacturing (WAAM) was applied to build samples for microstructural analyses and compression tests. A stress relief (SR) and a solution treatment and annealing (STA) was performed. It was found that SR had no influence on multi-layered samples due to intrinsic heat-treatment. A STA heat-treatment led to a reduction in the mechanical strength. Helium as process gas resulted in an increased mechanical strength due to higher heat capacity compared to argon.

scholarly journals Heat treatment effect on the mechanical properties, roughness and bone ingrowth capacity of 3D printing porous titanium alloy

RSC Advances ◽  
2018 ◽  
Vol 8 (22) ◽  
pp. 12471-12483 ◽  
Author(s):  
Zuhao Li ◽  
Chang Liu ◽  
Bingfeng Wang ◽  
Chenyu Wang ◽  
Zhonghan Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Titanium Alloy ◽  
3D Printing ◽  
Mechanical Strength ◽  
Clinical Application ◽  
Treatment Effect ◽  
Bone Ingrowth ◽  
Porous Titanium

The weak mechanical strength and biological inertia of Ti–6Al–4V porous titanium alloy limit its clinical application in the field of orthopedics.

scholarly journals Evolution of Microstructure during Isothermal Treatments of a Duplex-Austenitic 0.66C11.4Mn.9.9Al Low-Density Forging Steel and Effect on the Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 214
Author(s):  
Idurre Kaltzakorta ◽  
Teresa Gutierrez ◽  
Roberto Elvira ◽  
Pello Jimbert ◽  
Teresa Guraya
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Strength ◽  
Grain Boundaries ◽  
Automotive Industry ◽  
Carbide Precipitation ◽  
Water Quenching ◽  
Low Density ◽  
Evolution Of Microstructure ◽  
Kappa Carbide

In the last decades, low-density steels for forging have increasing interest in the automotive industry, and good mechanical properties are required for their real application. This paper describes the results obtained for a 0.66C11.4Mn9.9Al duplex austenitic low-density steel after applying a set of isothermal treatments at different combinations of time and temperature, aimed to promote kappa carbide precipitation, and improve the mechanical properties obtained with a water quenching treatment. The effects of the different isothermal treatments on the microstructure and on the mechanical properties have been analyzed and compared to those obtained from a quenching heat treatment. We found that isothermal treatments in the range temperature between 550–750 °C promoted the profuse precipitation of coarse kappa carbides at grain boundaries, which dramatically reduced the ductility of the alloy, whereas a traditional quenching treatment resulted in a better combination of ductility and mechanical strength.

scholarly journals Effect of the addition of metakaolin on the carbonation of Portland cement concretes

2020 ◽  
Vol 13 (1) ◽  
pp. 1-18
Author(s):  
B. S. SANTOS ◽  
D. D. M. ALBUQUERQUE ◽  
D.V. RIBEIRO
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Portland Cement ◽  
Axial Compression ◽  
Capillary Absorption ◽  
Negative Contribution ◽  
Interstitial Solution ◽  
Pozzolanic Materials ◽  
Post Deposition ◽  
Concrete Reinforcement

Abstract Carbonation has been a concern of constructors and researchers because, by lowering the pH of the interstitial solution of the concrete, it can favor the post-deposition and subsequent corrosion of reinforced concrete reinforcement. Among the factors that influence carbonation is the use of pozzolanic materials, such as metakaolin. However, there is no consensus as to the positive or negative contribution of these additions. This work evaluated the influence of metakaolin on the mechanical properties, porosity and in particular on the carbonation of concrete, from the addition of 0%, 5%, 10% and 15% of metakaolin, in relation to the cement mass. From the results, it was observed that the addition of metakaolin, while not significantly influencing the porosity, gave the concrete a greater resistance to axial compression, a decrease in the capillary absorption and delayed the advance of the carbonation front in the concrete.

The Effect of Heat Treatment on the Structure and Mechanical Properties of Austempered Iron with Vermicular Graphite

2017 ◽  
Vol 891 ◽  
pp. 242-248 ◽  
Author(s):  
Zuzana Andršová ◽  
Pavel Kejzlar ◽  
Martin Švec ◽  
Bretislav Skrbek
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Strength ◽  
Dwell Time ◽  
Isothermal Temperature ◽  
Treatment Conditions

Austempered vermicular-graphite iron seem to be a perspective material because of its promising mechanical properties. These properties are strongly affected by parameters of applied heat treatment. Different heat treatment conditions (austenitizing dwell time, isothermal temperature and isothermal dwell) were varied and their effect on the structure and mechanical properties was evaluated and described. Properly selected heat treatment conditions lead to formation of ausferritic matrix with which is responsible for substantial increase in mechanical strength while maintaining sufficient ductility.

scholarly journals Altered Volcanic Tuffs from Los Frailes Caldera. A Study of Their Pozzolanic Properties

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5348
Author(s):  
Jorge Costafreda ◽  
Domingo Martín ◽  
Leticia Presa ◽  
José Parra
Keyword(s):  
Electrical Conductivity ◽  
Portland Cement ◽  
Mechanical Strength ◽  
Iberian Peninsula ◽  
Volcanic Glass ◽  
Petrographic Analysis ◽  
High Mechanical Strength ◽  
Physical Chemical ◽  
Strength Tests ◽  
Pozzolanic Properties

This work presents the results of the study of the physical, chemical, mineralogical and pozzolanic properties of the altered volcanic tuffs (AVT) that lie in the Los Frailes caldera, south of the Iberian Peninsula, and demonstrates their qualities as pozzolans for the manufacturing of mortars and pozzolanic cements of high mechanical strength. The main objective of this research is to show to what extent the AVTs can replace portland cement (PC) in mortars, with standardised proportions of 75:25% and 70:30% (PC-AVT). To achieve these objectives, three AVT samples were studied by a petrographic analysis of thin section (PATS), DRX, FRX and MEB. The pozzolanic properties were determined by three methods: electrical conductivity (ECT), chemical pozzolanicity tests (CPT) at 8 and 15 days and mechanical strength tests (MS) of the specimens at 2, 7, 28 and 90 days. Studies of a PATS, DRX, FRX and MEB showed that the AVT samples’ constitutions are complex where smectite (montmorillonite), mordenite, quartz, halloysite, illite, kaolinite, volcanic glass and lithic fragments coexist. The results of the ECT and CPT tests confirmed the pozzolanic properties of the samples analysed and proved an increase in mechanical strength from 2 to 90 days of testing.

scholarly journals Effect of Al 6061 Alloy Compositions on Mechanical Properties of the Automotive Steering Knuckle Made by Novel Casting Process

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 857 ◽  
Author(s):  
Gyu Jeon ◽  
Ki Kim ◽  
Jung-Hwa Moon ◽  
Chul Lee ◽  
Whi-Jun Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Strength ◽  
Casting Process ◽  
Optimal Conditions ◽  
Al 6061 ◽  
Minor Elements ◽  
Commercial Grade ◽  
Before And After ◽  
Elongation Percentage

This study demonstrates the feasibility of a novel casting process called tailored additive casting (TAC). The TAC process involves injecting the melt several times to fabricate a single component, with a few seconds of holding between successive injections. Using TAC, we can successfully produce commercial-grade automotive steering knuckles with a tensile strength of 383 ± 3 MPa and an elongation percentage of 10.7 ± 1.1%, from Al 6061 alloys. To produce steering knuckles with sufficient mechanical strength, the composition of an Al 6061 alloy is optimized with the addition of Zr, Zn, and Cu as minor elements. These minor elements influence the thermal properties of the melt and alloy, such as their thermal stress, strain rate, shrinkage volume, and porosity. Optimal conditions for heat treatment before and after forging further improve the mechanical strength of the steering knuckles produced by TAC followed by forging.

Pozzolanicity Evaluation of Mineral Additions by Electrical Conductivity Measurements

2016 ◽  
Vol 881 ◽  
pp. 239-244
Author(s):  
Felipe Araujo Cedrim ◽  
Guilherme Augusto de Oliveira e Silva ◽  
Tiago Assunção Santos ◽  
Daniel Véras Ribeiro
Keyword(s):  
Electrical Conductivity ◽  
Portland Cement ◽  
Silica Fume ◽  
Conductivity Measurements ◽  
Alternative Materials ◽  
Mineral Additions ◽  
Pozzolanic Materials ◽  
Pozzolanic Properties

The search for alternative materials that can replace Portland cement promotes discussion about the use of pozzolanic materials in cementitious matrices. Several techniques and procedures can determine the pozzolanic properties of a particular material based on electrical conductivity. Being an innovative and a subject of demand and minimum resource method, this article seeks validation by the comparison with chemical titration tests. To this end, were tested several possible pozzolanic materials (silica fume, metakaolin and eucalyptus ash) through the mentioned techniques

Physical and Mechanical Properties of Cement Pastes with Blended Binder Containing Fine Milled Glass

2015 ◽  
Vol 824 ◽  
pp. 71-76
Author(s):  
Markéta Kočová ◽  
Jaroslav Pokorný ◽  
Milena Pavlíková ◽  
Zbyšek Pavlík
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Portland Cement ◽  
Size Distribution ◽  
Borosilicate Glass ◽  
Physical And Mechanical Properties ◽  
Fluorescence Analysis ◽  
Pozzolanic Activity ◽  
Cement Pastes

Physical and mechanical behaviour of cement pastes with partial Portland cement replacement by fine milled waste glass is researched in the presented paper. The tested pastes contain milled borosilicate glass in amount of 5, 10, 20, and 30 mass% of cement. The chemical composition of borosilicate glass and used Portland cement is accessed by XRF (X-Ray Fluorescence) analysis. For the milled glass, pozzolanic activity and particle size distribution are measured. Here, modified Chapelle test is used for evaluation of pozzolanic activity. Particle size distribution is measured on laser diffraction principle. Basic physical properties and mechanical properties are determined for samples cured 28 and 90 days in water in order to evaluate the kinetics of hydration process. The obtained results revealed the possible applicability of the tested borosilicate glass in the composition of cement-based composite materials.

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