scholarly journals Investigation on the Mechanical Properties and Microstructure of Eco-friendly Mortar Containing WGP at Elevated Temperature

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arash Sedaghatdoost ◽  
Kiachehr Behfarnia ◽  
Hamidreza Moosaei ◽  
Mohammad Bayati ◽  
Mohammad Sadegh Vaezi
Keyword(s):  
High Temperatures ◽  
Elevated Temperatures ◽  
Strength Loss ◽  
Sustainable Construction ◽  
Partial Replacement ◽  
Optimum Ratio ◽  
Iron Compounds ◽  
Waste Glass Powder ◽  
Petrographic Examination ◽  
Before And After

AbstractThe properties of mortars containing waste glass powder (WGP) as a cement substitute for sustainable construction at various high temperatures were investigated. For this purpose, specimens from four mixtures with WGP at various percentage levels of 0, 5, 10 and 15% were prepared and exposed to the specified temperatures. After that, the compressive and flexural strength were determined at high temperatures. The mass loss was also measured by weighing the samples before and after exposing to the high temperatures. The microstructure of mortars was analyzed by petrographic examination. Based on the obtained results, incorporation of WGP as partial replacement of cement could improve strength characteristics of the mortars at the elevated temperatures up to 17%. Also, the optimum ratio of cement replacement level was found to be 10%. In addition, the petrographic images of the mortars showed that at the same time with the strength loss of specimens, the red discoloration of WGP occurred that is attributed to the oxidation of iron compounds that starts at temperatures above 200 °C.

scholarly journals Effect of elevated temperatures on alkali-activated tungsten mining waste based materials

2019 ◽  
Vol 274 ◽  
pp. 03001
Author(s):  
Rafael Silva-Figueiredo ◽  
João Castro-Gomes
Keyword(s):  
Particle Size ◽  
High Temperatures ◽  
Compression Test ◽  
Glass Powder ◽  
Elevated Temperatures ◽  
Mining Waste ◽  
Waste Glass ◽  
Waste Glass Powder ◽  
Before And After ◽  
Alkali Activated

Generally, alkali-activated materials (aka geopolymers) present good behaviour at high temperatures, but previous studies of geopolymers under elevated temperatures are, in most cases, focused on metakaolin or fly ash based geopolymers, making the information on geopolymers with mining waste mud almost inexistent. In this paper, were analysed geopolymers with different combinations of mining waste mud, waste glass powder, metakaolin and expanded cork in a total of 15 different mixtures using sodium hydroxide and sodium silicate as alkaline activators. Materials particle size used is under 500 μm for mining waste mud, waste glass powder. Some mixtures also included expanded granulated cork with particle size between 2 to 4 mm. Ten samples with 40 × 40 × 40 mm dimensions were used for the compression test, one sample for the TGA test, and one cube (100 × 100 × 60 mm) with a frustoconical hole (50 mm deep) and a 100 × 100 × 25 mm cover, for the cup test. All the mixtures were cured for 24h at a temperature of 60 °C before being demoulded, and left at room temperature until they reach 7 days to be tested. On the 7th day, of each mixture, samples were placed in a static furnace before the compression test submitted to a temperature of 800 °C during 2h. Then, the compression test was performed and the values before and after exposure to high temperatures were compared. Were recorded maximum gains of 724% and maximum losses of 100% in the compressive strength. This preliminary result shows the potentials of mining waste alkali-activated materials for elevated temperatures applications.

scholarly journals Behavior of Steel Slag Concrete Subjected to Elevated Temperature

2020 ◽  
Vol 9 (4) ◽  
pp. 1165-1170
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Coarse Aggregate ◽  
Steel Slag ◽  
Partial Replacement ◽  
High Porosity ◽  
Residual Mechanical Properties

Recycling of materials has become a major interest for engineers. At present, the amount of slag deposited in storage yard adds up to millions of tons/year leading to the occupation of farm land and serious pollution to the environment, as a result of the rapid growth in the steel industry. Steel slag is made at 1500- 1650°C having a honey comp shape with high porosity. Using steel slag as the natural aggregate with a lower waste material cost can be considered as a good alternative for sustainable constructions. The objective of this study is to evaluate the performance of residual mechanical properties of concrete with steel slag as coarse aggregate partial replacement after exposing to high temperatures .This study investigates the behavior of using granulated slag as partial or fully coarse aggregate replacement with different percentages of 0%, 15%, 30%, 50% and 100% in concrete when subjected to elevated temperatures. Six groups of concrete mixes were prepared using various replacement percentages of slag exposed to different temperatures of 400 °C, 600 °C and 800 °C for different durations of 1hr, 1.5hr and 2hr. Evaluation tests were compressive strength, tensile strength, and bond strength. The steel slag concrete mixes showed week workability lower than control mix. A systematic increasing of almost up to 21.7% in compressive strength, and 66.2% in tensile strength with increasing the percentage of steel slag replacement to 50%. And the results showed improvement on concrete residual mechanical properties after subjected to elevated temperatures with the increase of steel slag content. The findings of this study give an overview of the effect of steel slag coarse aggregate replacement on concrete after exposed to high temperatures.

scholarly journals PERFORMANCE OF CONCRETE MODIFIED WITH DISCARDED GLASS AT ELEVATED TEMPERATURES FOR SUSTAINABLE CONSTRUCTION

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Oluwarotimi Olofinnade ◽  
Anthony Ede ◽  
Ben Ngene ◽  
Akpabot Akpabot
Keyword(s):  
Elevated Temperatures ◽  
Soda Lime ◽  
Sustainable Construction ◽  
Soda Lime Glass ◽  
Air Cooling ◽  
Before And After ◽  
Natural Aggregates ◽  
Temperature Exposure ◽  
Heating Test ◽  
Constant Heating

This study examines the residual strength of concrete produced with crushed discarded soda-lime glass as aggregates after exposure to elevated heating. The natural aggregates, which comprise both the coarse and fine aggregates were partially and completely replaced by 0, 25, 50, 75 and 100% of the discarded glass. The control and samples containing crushed discarded glass aggregates were prepared at constant water-cement ratio (w/c) of 0.50 and the cube samples were exposed to temperatures of 60, 150, 300 and 500°C after curing in water for 90 days. The heating was increased at a constant heating rate of 10°C/min. The strength of the concrete samples was measured before and after exposure to heating after air-cooling of the heated samples. Moreover, scanning electron microscope (SEM) examination was carried out on selected samples to investigate the extent of change in the concrete bonding, especially at higher heating. Test results depict reduction trend in the characteristic strength of the tested samples as the level of heating increases, while the SEM micrographs reveal clear decomposition in the concrete interfaces. However, it was noticed from the results that concrete containing crushed discarded glass show better performance in terms of strength compared to the reference concrete at certain temperature exposure indicating a modified concrete with improved post-fire resistance.

The Effects of the Heating Conditions on the Hydro-Formability of the Aluminum Alloys at High Temperatures

2005 ◽  
Vol 475-479 ◽  
pp. 3307-3310 ◽  
Author(s):  
B.J. Kim ◽  
S.M. Son ◽  
K.S. Park ◽  
Young Hoon Moon
Keyword(s):  
Aluminum Alloys ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Heating Time ◽  
Age Hardening ◽  
Dynamic Strain ◽  
Forming Process ◽  
Before And After ◽  
Hydroforming Process ◽  
Warm Hydroforming

Modern automobiles are built with a steadily increasing variety of materials and semifinished products. The traditional composition of steel sheet and cast iron is being replaced with other materials such as aluminum and magnesium. But low formability of these materials has prevented the application of the automotive components. The formability can be enhanced by conducting the warm hydroforming using induction heating device which can raise the temperature of the specimen very quickly. The specimen applied to the test is AA6061 extruded tubes which belong to the age-hardenable aluminum alloys. But in the case of AA6061 age hardening occurs at room temperature or at elevated temperatures before and after the forming process. In this study the effects of the heating condition such as heating time, preset temperature, holding time during die closing and forming time on the hydroformability are analyzed to evaluate the phenomena such as dynamic strain hardening and ageing hardening at high temperatures after the hydroforming process.

EASTERN STAINLESS TYPE 310S

Alloy Digest ◽  
1984 ◽  
Vol 33 (8) ◽  
Keyword(s):  
High Temperatures ◽  
Elevated Temperatures ◽  
High Strength ◽  
Heat Treating ◽  
Oil Refining ◽  
Steel Company ◽  
Plant Equipment ◽  
The Many ◽  
Corrosion And Oxidation ◽  
Refining Equipment

Abstract EASTERN STAINLESS TYPE 310S has high resistance to corrosion and oxidation at high temperatures. It also has high strength at elevated temperatures. Thus it is especially suitable for service at high temperatures. It is very ductile and can be welded readily. Among the many applications for Type 310S, a few typical uses include annealing boxes, chemical plant equipment, fire box sheets, furnace linings, heat exchangers, oil-refining equipment, kiln linings and tube hangers. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-450. Producer or source: Eastern Stainless Steel Company.

Microstructure and Mechanical Properties of Ti-6Al-4V Manufactured by SLM

2015 ◽  
Vol 651-653 ◽  
pp. 677-682 ◽  
Author(s):  
Anatoliy Popovich ◽  
Vadim Sufiiarov ◽  
Evgenii Borisov ◽  
Igor Polozov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Behavior ◽  
Ductile Fracture ◽  
Elevated Temperatures ◽  
Initial Material ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Before And After

The article presents results of a study of phase composition and microstructure of initial material and samples obtained by selective laser melting of titanium-based alloy, as well as samples after heat treatment. The effect of heat treatment on microstructure and mechanical properties of specimens was shown. It was studied mechanical behavior of manufactured specimens before and after heat treatment at room and elevated temperatures as well. The heat treatment allows obtaining sufficient mechanical properties of material at room and elevated temperatures such as increase in ductility of material. The fractography of samples showed that they feature ductile fracture with brittle elements.

scholarly journals Deformation of Ordered Mesoporous Silica Structures on Exposure to High Temperatures

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
John B. Lowe ◽  
Richard T. Baker
Keyword(s):  
Mesoporous Silica ◽  
Pore Structure ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Ordered Mesoporous Silica ◽  
Large Cage ◽  
Pore Structures ◽  
Ordered Mesoporous ◽  
Pore Size Distributions ◽  
Wide Range

Ordered mesoporous silica materials are of interest for a wide range of applications. In many of these, elevated temperatures are used either in the preparation of the material or during its use. Therefore, an understanding of the effect of high temperature treatments on these materials is desirable. In this work, a detailed structural study is performed on silicas with three representative pore structures: a 2-D hexagonal pore arrangement (SBA-15), a continuous 3D cubic bimodal pore structure (KIT-6), and a 3D large cage pore structure (FDU-12). Each silica is studied as prepared and after treatment at a series of temperatures between 300 and 900°C. Pore structures are imaged using Transmission Electron Microscopy. This technique is used in conjunction with Small-Angle X-ray Diffraction, gas physisorption, and29Si solid state Nuclear Magnetic Resonance. Using these techniques, the pore size distributions, the unit cell dimensions of the mesoporous structures, and the relative occupancy of the distinct chemical environments of Si within them are cross correlated for the three silicas and their evolution with treatment temperature is elucidated. The physical and chemical properties before, during, and after collapse of these structures at high temperatures are described as are the differences in behavior between the three silica structures.

Structural Performance of Pultruded Composites under Elevated Temperatures

2009 ◽  
Vol 79-82 ◽  
pp. 2223-2226
Author(s):  
Ayman S. Mosallam
Keyword(s):  
Elevated Temperature ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Oxidative Degradation ◽  
Viscoelastic Behavior ◽  
Structural Performance ◽  
Crystalline Polymers ◽  
Damage To The Material ◽  
Continuous Working ◽  
Pultruded Composites

One of the major limitations for wider use of pultruded fiber reinforced polymeric (PFRP) composites in the civil engineering sector has been their behavior under elevated temperature and ultimately fire. This limitation arises not only due to the reduction in mechanical properties at high temperatures, including increased propensity to creep, but also due to limitations on the continuous working temperature causing permanent damage to the material as a result of thermal and oxidative degradation. Significant gains in property retention at high temperatures with crystalline polymers have been derived from the incorporation of fibrous reinforcement, but the development of new polymer matrices is the key for further elevation of the useful temperature range. This paper presents summary results of a research project focused on characterizing the viscoelastic behavior of commercially-produced, off-the-shelf unidirectional PFRP materials subjected to elevated temperature environments.

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