scholarly journals The Fabrication of Geopolymer Foam Composites Incorporating Coke Dust Waste

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1052
Author(s):  
Buczkowska Katarzyna ◽  
Chi Hiep Le ◽  
Petr Louda ◽  
Szczypiński Michał ◽  
Totka Bakalova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
Composite Foam ◽  
Coke Dust ◽  
Composite Foams ◽  
Negative Effect ◽  
Geopolymer Binder

This paper reports the results of an experimental investigation on the mechanical properties of geopolymer foams incorporating filler from the coke dust waste (CDW). In this work, CDW was used to replace a part of geopolymer paste at 5%, 10%, 20%, and 30% by geopolymer binder mass. The physico-mechanical properties and thermal resistance against high temperatures of CDW/geopolymer foams are presented. The primary results obtained show that the use of CDW in the production of geopolymer foam composites made it possible for them to achieve relatively good mechanical properties. However, the incorporation of the CDW into the geopolymer had a slightly negative effect on thermal conductivity, but significantly improved the mechanical strength of the final product. Moreover, this waste also helped the composite foam to achieve a structure with more uniform open pores distribution, compared to the pure foam. After exposure to elevated temperatures, the residual strength of the composite foams maintained well compared to the pure foams.

Experimental Investigation of Post-Fire Mechanical Properties of Quenched and Tempered High Strength Steel 07MnMoVR

2018 ◽  
Author(s):  
Shanshan Shao ◽  
Guodong Jia ◽  
Luowei Cao ◽  
Fakun Zhuang
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Impact Toughness ◽  
Residual Strength ◽  
High Strength Steel ◽  
Elevated Temperatures ◽  
High Strength ◽  
Stress Strain ◽  
Duration Time ◽  
Exposure Temperature

Quenched and tempered high strength steel 07MnMoVR with a better combination of mechanical properties and low susceptibility to welding crack has attracted attention for applications in engineering fields. Exposure to fire will subject steel to thermally induced environmental conditions that may alter the material’s properties. The residual strength after a fire event is important to assess the extent of the fire damage and the potential reusability of the vessel. This paper presents the details of an experimental investigation on the post-fire mechanical properties of 07MnMoVR steel. Uniaxial tension tests and Charpy impact tests were performed on coupons exposed to elevated temperatures varying from 550°C to 850°C for half an hour to 8 hours and then naturally cooled in air or cooled by water. The post-fire stress-strain curves, strength, ductility and impact toughness of 07MnMoVR steel are discussed. The results show that the yield plateau in post-fire stress-strain curves disappears when the exposure temperature is higher than 700°C. The residual yield strength and ultimate strength decrease firstly and increase afterward with increasing exposure temperature. The influences of duration time on the residual strength are considerable for exposure at 650°C. The post-fire impact toughness of 07MnMoVR steel at −20°C degrades drastically with increasing duration time when the exposure temperature reaches 700°C. The effects of cooling methods on strength and toughness become significant when the exposure temperature exceeds 750°C. The critical tempetature for the mechanical properties deterioration is 650°C. This study can provide basis data and guidelines for the fitness for service assessment of 07MnMoVR steel suffered from fire accident.

BRUSH ALLOY 3

Alloy Digest ◽  
1983 ◽  
Vol 32 (3) ◽  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Copper Alloy ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Heat Treating ◽  
Good Resistance ◽  
Good Corrosion Resistance

Abstract BRUSH Alloy 3 offers the highest electrical and thermal conductivity of any beryllium-copper alloy. It possesses an excellent combination of moderate strength, good corrosion resistance and good resistance to moderately elevated temperatures. Because of its unique physical and mechanical properties, Brush Alloy 3 finds widespread use in welding applications (RWMA Class 3), current-carrying springs, switch and instrument parts and similar components. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-454. Producer or source: Brush Wellman Inc..

scholarly journals Effect of Elevated Temperature on Mechanical Properties of High-Volume Fly Ash-Based Geopolymer Concrete, Mortar and Paste Cured at Room Temperature

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1473
Author(s):  
Jun Zhao ◽  
Kang Wang ◽  
Shuaibin Wang ◽  
Zike Wang ◽  
Zhaohui Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
High Volume ◽  
Sem Analysis ◽  
Geopolymer Concrete ◽  
Ordinary Concrete ◽  
Exposure Temperature

This paper presents results from experimental work on mechanical properties of geopolymer concrete, mortar and paste prepared using fly ash and blended slag. Compressive strength, splitting tensile strength and flexural strength tests were conducted on large sets of geopolymer and ordinary concrete, mortar and paste after exposure to elevated temperatures. From Thermogravimetric analyzer (TGA), X-ray diffraction (XRD), Scanning electron microscope (SEM) test results, the geopolymer exhibits excellent resistance to elevated temperature. Compressive strengths of C30, C40 and C50 geopolymer concrete, mortar and paste show incremental improvement then followed by a gradual reduction, and finally reach a relatively consistent value with an increase in exposure temperature. The higher slag content in the geopolymer reduces residual strength and the lower exposure temperature corresponding to peak residual strength. Resistance to elevated temperature of C40 geopolymer concrete, mortar and paste is better than that of ordinary concrete, mortar and paste at the same grade. XRD, TGA and SEM analysis suggests that the heat resistance of C–S–H produced using slag is lower than that of sulphoaluminate gel (quartz and mullite, etc.) produced using fly ash. This facilitates degradation of C30, C40 and C50 geopolymer after exposure to elevated temperatures.

The Influence of Amount of Wood Fiber on New Flame-Retardant Melamine-Urea-Formaldehyde (MUF) Composite Foam

2011 ◽  
Vol 393-395 ◽  
pp. 1012-1017 ◽  
Author(s):  
Yu Feng Ma ◽  
Wei Zhang ◽  
Ling Li ◽  
Ming Ming Zhang ◽  
Zeng Hui Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Cell Shape ◽  
Urea Formaldehyde ◽  
Wood Fiber ◽  
Cell Size Distribution ◽  
Composite Foam ◽  
Composite Foams ◽  
Flame Retardant Properties ◽  
Irregular Cell

New composite foams were prepared by co-foaming of Melamine-Urea-Formaldehyde (MUF) resin and wood fiber in the closed mould at 70°C. The effects of amount of wood fiber on mechanical properties, brittleness, flame-retardant, insulation and microscopic structures of wood fiber-MUF foam were investigated. Results indicated that the flame-retardant properties increased, and the brittleness and mechanical properties decreased with the increase of the amount of wood fiber in composite foams. The addition of wood fiber resulted in more uniform cell size distribution and irregular cell shape, but had little effect on insulation properties.

Experimental investigation and probabilistic models for residual mechanical properties of GFRP pultruded profiles exposed to elevated temperatures

2019 ◽  
Vol 211 ◽  
pp. 610-629 ◽  
Author(s):  
Esmaeil Pournamazian Najafabadi ◽  
Mohammad Houshmand Khaneghahi ◽  
Hossein Ahmadie Amiri ◽  
Homayoon Esmaeilpour Estekanchi ◽  
Togay Ozbakkaloglu
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Probabilistic Models ◽  
Elevated Temperatures ◽  
Residual Mechanical Properties

scholarly journals Effect of Temperature and Sisal Fiber Content on the Properties of Plaster of Paris

2018 ◽  
Vol 7 (4.20) ◽  
pp. 205 ◽  
Author(s):  
Aqil M. ALmusawi ◽  
Thulfiqar S. Hussein ◽  
Muhaned A. Shallal
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Fiber Content ◽  
Sisal Fiber ◽  
Effect Of Temperature ◽  
Plaster Of Paris ◽  
Micro Cracks ◽  
Recent Developments ◽  
Negative Effect

Recent developments in the production of ecologically friendly building composites have led to a renewed interest in the use of vegetable fibers as a reinforcement element. Traditional pure Plaster of Paris (POP) can suffer from the development of micro-cracks due to thermal expansion. Therefore, sisal fiber was studied for its potential as an ecological element to restrict and delay the development of micro-cracks in POP. Different sisal proportions of 0, 2, 4, 6, 8 and 10 wt. % of POP were used to characterize the physical and mechanical properties of POP at the ambient temperature. Then, the effects of temperatures of 25, 100, 200, 300, 400 and 500  were investigated. Results proved that the composite of 10% sisal fiber had the best mechanical properties. Also, when the fiber content was increased, the composite’s performance was enhanced, becoming better able to resist elevated temperatures. However, raising the temperature to 300 or above had a negative effect on the mechanical properties, which were significantly decreased due to the degradation of the sisal fiber. 

scholarly journals Mechanical Properties of Manufactured-Sand Concrete after High Temperatures

2015 ◽  
Vol 9 (1) ◽  
pp. 1007-1011
Author(s):  
Zhengfa Chen ◽  
Hehua Zhu ◽  
Zhiguo Yan ◽  
Gaojv Peng
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Mass Loss ◽  
High Temperatures ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
Raw Materials ◽  
Concrete Mixture ◽  
Calculation Formula ◽  
Manufactured Sand

In this paper, to study mechanical properties of manufactured-sand concrete after high temperatures, experiments on the residual strength of manufactured-sand concrete were carried out under high temperatures in which raw materials performances and concrete mixture proportion were considered. The mechanism of elevated temperatures on residual strength was theoretically discussed, and the calculation formula of residual strength was given. The results indicated that with the increasing of temperature, the mass loss was small while the reducing of strength and the elastic modulus of manufactured-sand concrete were significantly.

scholarly journals Post-fire mechanical properties of high strength steels

2018 ◽  
Author(s):  
Ben Young ◽  
Hai-Ting Li
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Ambient Temperature ◽  
High Strength Steel ◽  
Elevated Temperatures ◽  
Weight Ratio ◽  
High Strength Steels ◽  
High Strength ◽  
Predictive Equations ◽  
Retention Factors

High strength steels are becoming increasingly attractive for structural and architectural applications due to their superior strength-to-weight ratio which could lead to lighter and elegant structures. The stiffness and strength of high strength steels may reduce after exposure to fire. The post-fire mechanical properties of high strength steels have a crucial role in evaluating the residual strengths of these materials. This paper presents an experimental investigation on post-fire mechanical properties of cold-formed high strength steels. A series of tensile coupon tests has been carried out. The coupon specimens were extracted from cold-formed square hollow sections with nominal yield stresses of 700 and 900 MPa at ambient temperature. The specimens were exposed to various elevated temperatures ranged from 200 to 1000 °C and then cooled down to ambient temperature before tested to failure. Stress-strain curves were obtained and the mechanical properties, namely, Young’s modulus, yield stress (0.2% proof stress) and ultimate strength, of the cold-formed high strength steel materials after exposure to elevated temperatures were derived. The post-fire retention factors that obtained from the experimental investigation were compared with existing predictive equations in the literature. New predictive equations are proposed to determine the residual mechanical properties of high strength steels after exposure to fire. It is shown that the proposed predictive equations are suitable for both cold-formed and hot-rolled high strength steel materials with nominal yield stresses ranged from 690 to 960 MPa.

Fabrication and characterization of carbon nanofibers coated expandable thermoplastic microspheres-based polymer composites

2022 ◽  
Vol 05 ◽  
Author(s):  
Wanda Jones ◽  
Bedanga Sapkota ◽  
Brian Simpson ◽  
Tarig A. Hassan ◽  
Shaik Jeelani ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Thermal Properties ◽  
Carbon Nanofibers ◽  
Spherical Particles ◽  
Sonochemical Method ◽  
Thermal And Mechanical Properties ◽  
Polymer Shell ◽  
Composite Foam ◽  
Composite Foams

Background: Thermoplastic expandable microspheres (TEMs) are spherical particles that consist of polymer shell encapsulating a low boiling point liquid hydrocarbon that acts as the blowing agent. When TEMs are heated at 80-190 C, the polymer shell softens and the hydrocarbon gasifies, causing the microspheres expand leading to increase in volume and decrease in density. TEMs are used in food packaging, elastomeric cool roof coatings, shoe soles, fiber and paper board, and various applications in the automotive industry. It is noted that TEMs are known by its brand name ‘Expancel’ which is also used to refer TEMs in this paper. Objective: The objective of this work was to develop and characterize forms prepared from TEMs with/without carbon nanofibers (CNFs) coatings to study the effect of CNFs on structural, thermal, and mechanical properties. Method: Sonochemical method was used to coat TEMs with various weight percentage (1, 2, and 3 %) of CNF. Neat foam (without CNF) and composite foams (TEMs coated with various wt.% of CNF) were prepared by compression molding the TEMs and TEMs-CNF composites powders. Thermal and mechanical properties of the neat and composite foams were investigated. Result: The mechanical properties of the composite foam were notably improved, which is exhibited by a 54% increase in flexural modulus and a 6% decrease in failure strain with the TEMs-(2 wt.% CNF) composite foam as compared to the neat foam. Improvement in thermal properties of composite foam was demonstrated by a 38% increase in thermal stability at 800 ºC with the TEMs-(1 wt.% CNF) composite foam as compared to the neat foam. However, no change in glass transition of TEMs was observed with the CNF coating. SEM-based analysis revealed that CNFs were well dispersed throughout the volume of the TEMs matrix forming a strong interface. Conclusions: Straightforward sonochemical method successfully triggered efficient coating of TEMs with CNFs resulting to strong adhesion interface. The mechanical properties of composite foams increased up to 2% of CNFs coating and then decreased with the higher coating presumably due to interwoven bundles and aggregation of CNFs, which might have acted as critical flaws to initiate and propagate cracking. Thermal properties of foams increased with the CNFs coating while no change in glass transition temperature was observed due to coating.

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