scholarly journals Mechanical Behavior of Al–Al2Cu–Si and Al–Al2Cu Eutectic Alloys

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 194
Author(s):  
Qian Lei ◽  
Jian Wang ◽  
Amit Misra
Keyword(s):  
Compressive Strength ◽  
Failure Strain ◽  
Cast Alloy ◽  
Maximum Strength ◽  
Eutectic Alloys ◽  
Microstructural Refinement ◽  
Melt Pool ◽  
Rapid Solidification Technique ◽  
Eutectic Morphology ◽  
Better Than

In this study, laser rapid solidification technique was used to refine the microstructure of ternary Al–Cu–Si and binary Al–Cu eutectic alloys to nanoscales. Micropillar compression testing was performed to measure the stress–strain response of the samples with characteristic microstructure in the melt pool regions. The laser-remelted Al–Al2Cu–Si ternary alloy was observed to reach the compressive strength of 1.59 GPa before failure at a strain of 28.5%, which is significantly better than the as-cast alloy with a maximum strength of 0.48 GPa at a failure strain of 4.8%. The laser-remelted Al–Cu binary alloy was observed to reach the compressive strength of 2.07 GPa before failure at a strain of 26.5%, which is significantly better than the as-cast alloy with maximum strength of 0.74 GPa at a failure strain of 3.3%. The enhanced compressive strength and improved compressive plasticity were interpreted in terms of microstructural refinement and hierarchical eutectic morphology.

Influence of Species of Manufactured Sand on Basic Performances of Mortar

2011 ◽  
Vol 306-307 ◽  
pp. 980-983
Author(s):  
Yu Li Wang ◽  
Su Xia Liu ◽  
Wei Dong Wang ◽  
Yu Jie Zhao
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Bulk Density ◽  
Maximum Strength ◽  
River Sand ◽  
Cement Ratio ◽  
Manufactured Sand ◽  
Better Than

The influences of sand-cement ratio on bulk density, fluidity, compressive strength, flexural strength of mortar of river sand, limestone manufactured sand (MA), quartzite MA, granite MA were studied compresively in the paper. The results show that bulk density of mortar reaches to maximum if sand-cement ratio of mortar of river sand is 2.73 and the ratios of mortar of manufactured fine sands are all 3.0. The fluidity of mortars of river sand and limestone MA are better than those of quartzite MA and granite MA. Sand-cement ratios of mortars with maximum strength are equal to that with maximum bulk density. The sequence of compressive strength is limestone MA, quartzite MA, river sand, granite MA from high to low, and that of flexural strength is limestone MA, quartzite MA, granite MA, river sand.

Electron Back Scattering Diffraction Analysis of A357 Alloy Modified by Sr

2010 ◽  
Vol 160-162 ◽  
pp. 831-835
Author(s):  
Zhong Wei Chen ◽  
Hai Fang Zhang ◽  
Jiang Chao Zhao
Keyword(s):  
Cast Alloy ◽  
Primary Aluminum ◽  
Mapping Technique ◽  
Eutectic Solidification ◽  
Preparation Technique ◽  
Ion Milling ◽  
A357 Alloy ◽  
Back Scattering ◽  
Eutectic Si ◽  
Eutectic Morphology

Microstructure of A357 alloy modified by Sr has been investigated by the Electron Back Scattering Diffraction (EBSD) mapping technique using a Field Emission Gun Scanning Electron Microscopy (FEG-SEM). An appropriate sample preparation technique by ion milling was applied to obtain a sufficiently smooth surface for EBSD mapping. Results show that the eutectic morphology in microstructure of A357 alloy modified by Sr was changed to fine fibrous, and the grain size was refined. By comparing the orientation of the aluminum in the eutectic to that of the primary aluminum dendrites, the nucleation and growth mechanism of the eutectic solidification in A357 cast alloy was determined. The eutectic Si phase of the modified sample nucleates on the heterogeneous nuclei located in the region between primary α-Al dendrites and grows up, while the eutectic Si phase of the sample without modification nucleates on the primary α-Al dendrites and grows up.

Study on the Mechanical Properties and Frost Resistance of Recycled Concrete Prepared by Village Construction Wastes

2011 ◽  
Vol 418-420 ◽  
pp. 406-410
Author(s):  
Jun Liu ◽  
Yao Li ◽  
Dan Dan Hong ◽  
Yu Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Frost Resistance ◽  
Cement Mortar ◽  
Strength Loss ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Replacement Rate ◽  
Concrete Mechanical Properties ◽  
Better Than

Abstract. Recycled aggregate—rural building material wastes pretreated by cement mortar—are applied into concrete with different replacement rates: 0, 25%, 50%, 75%, and 100%. Results from measurements of compressive strength, cleavage tensile strength, mass loss after fast freeze-thaw cycles, and compressive strength loss indicate that a different recycled aggregate replacement rate certainly influences concrete mechanical properties and frost resistance. Recycled aggregate replacement rates less than 75% performs better than common concrete. Data from the 100% replacement rate is worse than that of rates less than 75% but still satisfy the general demands of GB standard on C30 concrete.

Study on Performance of Paste Filling with Urban Construction Waste

2014 ◽  
Vol 528 ◽  
pp. 127-131
Author(s):  
Yin Liu ◽  
Hao Qiang Zhang ◽  
Qi Feng Wang ◽  
Hai Yun Zhang
Keyword(s):  
Compressive Strength ◽  
Concrete Structures ◽  
Physical Property ◽  
System Engineering ◽  
Source Material ◽  
Construction Waste ◽  
Urban Construction ◽  
Better Than

Aiming at the problem of only source material in paste filling and garbage-surrounded city, a system engineering including them was proposed. The construction waste crushing process of filling was optimized based on the gangue process. Compared with gangue, the physical property of three kinds of construction waste ranged widely. Also the paste of all could reach the goal of filling, which the collapsed slump ranged from 18cm to 23cm and the highest compressive strength of 8h and 28d reached 0.17MPa and 3.82MPa. However, the properties of concrete structures of construction waste were better than that of brick-mixed structures.

Strength and Consolidation Mechanism of Green Pellets Containing Carbon

2011 ◽  
Vol 402 ◽  
pp. 215-220 ◽  
Author(s):  
Ru Fei Wei ◽  
Jia Xin Li ◽  
Guang Wu Tang
Keyword(s):  
Compressive Strength ◽  
Capillary Force ◽  
Phenolic Resin ◽  
Viscous Force ◽  
Chemical Adsorption ◽  
Adsorption Effect ◽  
Green Pellet ◽  
Pellet Strength ◽  
Better Than

The effects of four inorganic binders and four organic binders on strength of green pellet containing carbon were studied. The results show that phenolic resin is the best binder, compressive strength and drop strength of preheated pellet are 312.5 N and 15.1 times, respectively, when the matching was 2%. The reason is that chemical adsorption effect occurs in pellet. Strength of wet pellet is mainly maintained by capillary force. However, preheated pellet is mainly maintained by chemical adsorption effect and viscous force. Chemical adsorption effect is better than viscous force.

Strength Assesment of Asphaltic Concrete using Bitumen, Natural Fibre and Stone Dust: A Critical Review

2021 ◽  
Vol 9 (VI) ◽  
pp. 3044-3050
Author(s):  
Divesh Sharma
Keyword(s):  
Compressive Strength ◽  
Natural Fibre ◽  
Maximum Strength ◽  
Sisal Fiber ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Asphaltic Concrete ◽  
Stone Dust ◽  
Strength And Durability ◽  
Research Studies

In this review article, the usage of bitumen, sisal fiber and the sisal fiber for improving the strength parameters of concrete is discussed in detail. Numerous research studies related to the usage of bitumen, sisal fiber and stone dust are studied in detail to determine the results and outcome out of it. Previous research works showed that all, these materials were enhancing the strength and durability aspects of the concrete and depending upon the research studies certain outcomes has been drawn which are as follows. The studies related to the usage of the bitumen or asphalt in concrete so as to produce bituminous concrete or asphaltic concrete, the previous research works conclude that the maximum strength was attained at 5 percent usage of the bitumen and after further usage the general compressive strength of the concrete starts declining. The previous studies related to the usage of the sisal fiber showed that with the usage of the sisal fiber in the concrete, the strength aspects of concrete were improving and the maximum strength was obtained at 1.5 percent usage of the sisal fiber and after his the strength starts declining. Further the studies related to the usage of the stone dust showed that with the usage of stone dust as partial replacement of the natural fine aggregate the compressive strength of the concrete was improving and it was conclude that with the increase in the percentage of the stone dust, the compressive strength of the concrete was increasing.

Compressive Strength Analysis of MWD Microchip Tracer

2014 ◽  
Vol 511-512 ◽  
pp. 561-564
Author(s):  
Ji Bo Li ◽  
Wei Ning Ni ◽  
San Guo Li ◽  
Zu Yang Zhu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Compressive Strength ◽  
Working Conditions ◽  
Failure Criterion ◽  
Strength Analysis ◽  
Design Phase ◽  
Key Issues ◽  
Simulation Results ◽  
Better Than

Pressure resistant performance of Measure While Drilling (MWD) microchip tracer to withstand the harsh downhole environment is one of the key issues of normal working. Therefore, it is an effective way to analyze pressure resistant performance of the tracer in the design phase. Compressive strength of the tracer was studied based on finite element method. Considering downhole complexity and working conditions during the processing of tracer roundness, material non-uniformity and other factors. In this study, researchers took sub-proportion failure criterion to determine the failure of tracer. Simulation results of two structures, with pin and without pin, show that both structures met the requirement of downhole compressive strength, and the structure with pin was better than the structure without pin. This study provides basis for downhole application of microchip tracers.

scholarly journals Response of Recycled Brick Aggregate Concrete to High Temperatures

2019 ◽  
Vol 8 (10) ◽  
pp. 224-227
Keyword(s):  
Mechanical Properties ◽  
Air Pollution ◽  
Compressive Strength ◽  
Construction Industry ◽  
Fire Performance ◽  
Demolition Waste ◽  
Aggregate Concrete ◽  
Different Temperatures ◽  
Better Than ◽  
Made In

The abundant availability of demolition waste from construction industry is leading towards a significant problem of disposal, land and air pollution. The natural aggregate resources are also depleting due to development of construction activities. An attempt is made in this study to convert this waste into wealth by substituting the recycled brick from demolition waste to granite aggregate in production of the concrete. The granite aggregate (GA) is replaced with recycled brick aggregate (RBA) by 25% of its weight to produce M15 and M20 grades of concrete. The granite aggregate concrete (GAC) and recycled brick aggregate concrete (RBAC) were subjected to different temperatures between 100 to 1000oC for a duration of 3 hours and the mechanical properties such as compressive strength and flexural strength were examined to assess its fire performance. The response of RBAC is better than GAC at each temperature. The study revealed that the residual strength increases with the increase in grade of concrete at all temperatures.

scholarly journals Evaluation of strength characteristics for palm kernel oil - based Polyurethane (PKO-P) as a ground improvement method

2017 ◽  
Vol 12 (4) ◽  
Author(s):  
Diana Che Lat ◽  
Ismacahyadi Bagus Mohamed Jais ◽  
Kamaruzzaman Mohammed ◽  
Bahardin Baharom ◽  
Nastasa Samat ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Pile Foundation ◽  
Maximum Stress ◽  
Ground Improvement ◽  
Palm Kernel ◽  
Maximum Strength ◽  
Strength Characteristics ◽  
Soft Ground ◽  
Palm Kernel Oil ◽  
Kernel Oil

 Development on soft ground area cannot be avoided at certain area especially nearby coastal or marine area. At urban areas, most of the land has been fully developed and very limited space available, therefore area nearby marine region has to be explored to cater increasing in population in certain country. It is very crucial to stabilize the soft ground before any construction carried out to ensure the structure would be founded on the stable foundation system. Foundation system commonly established for deep soft ground is a pile foundation. There are certain cases whereby pile foundation system failed after completion of structure and the building has been accommodated or been utilized. It causes large settlement which contributes to the failure of structure such as longitudinal crack, sinkholes, beam fractured and so forth. Rectification works have to be done to restore foundation strength thus to prevent further settlement which can cause collapse or major failure of structure. Rectification works that commonly being done nowadays is underpinning pile whereby new pile being installed in between the existing pile to stabilize the foundation and prevent further settlement. This method rather wearisome to be carried out since it involves major excavation and disturbs the existing structure and the surrounding. Therefore it is proposed to carry out Palm Kernel Oil Based Polyurethane (PKO-P) Pile injection to overcome this problem. PKO-P pile injection is a lightweight material to prevent further settlement and the rectification works can be done very fast. No excavation is required and only a small diameter of hole is drilled on the existing slab foundation before injection of PKO-P Pile. PKO-P is a polyurethane processed from palm kernel oil which is renown of the sustainability and green materials. In this research, Unconfined Compression Test been have conducted on few samples of PKO-P materials with different ratio of polyol and isocynate to determine the compressive strength characteristics for PKO-P materials as such to evaluate the performance of the PKO-P for ground improvement. From the test that has been done, the compressive strength achieves its maximum strength at isocynate to polyol ratio of 1:0.75 with maximum compressive strength of 2.3MPa. PKO-P shows rigid characteristics at this maximum strength which produce strong material, able to resist deformation but brittles beyond the maximum stress. With further increasing amount of polyol, PKO-P shows flexible characteristics whereby it undergoes deformation but they tend not to break beyond the maximum stress. Higher elastic modulus recorded for rigid type PKO-P compare to flexible type PKO-P.

scholarly journals Effect of Elevated Temperature on Compressive Strength and Physical Properties of Neem Seed Husk Ash Concrete

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1198
Author(s):  
Kizito Patrick Mwilongo ◽  
Revocatus Lazaro Machunda ◽  
Yusufu Abeid Chande Jande
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Control Sample ◽  
Plain Concrete ◽  
Neem Seed ◽  
Seed Husk ◽  
High Temperature Rise ◽  
Different Levels ◽  
Fire Outbreak ◽  
Better Than

High temperature rise mostly caused by a fire outbreak is currently becoming a threat that endangers concrete’s structural performance for buildings and the safety of occupants. The behavior of concrete after fire subjection has been of much interest for the structural materials design purposes. This study investigated the physical properties and the compressive strength of M25 concrete incorporating Neem Seed Husk Ash (NSHA), exposed to and through targeted different levels of temperature (200 °C to 800 °C) for a period of three hours in an electric furnace. The NSHA was produced by calcining neem seed husks at 800 °C for six hours and then sieved through the 125 μm sieve. Different amounts of NSHA were investigated while considering the plain concrete as the control sample. 150 concrete cubes of 150 mm sizes were cast and properly cured for 7 and 28 days. The experimental results show that the compressive strength of the 5% NSHA concrete exposed to temperatures up to 400 °C is 21.3% and 23.8% better than the normal concrete at 7 and 28 curing days, respectively. Surface cracks and spalling are noticeable at 600 °C and 800 °C for all samples considered in this study.

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