Effect of Modified Phosphogypsum on the Mechanical Properties of Super Sulphate Cement

2012 ◽  
Vol 161 ◽  
pp. 264-268 ◽  
Author(s):  
Yu Xin Gao ◽  
Bao Ying Yu ◽  
Fen Lian Xu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Chemical Composition ◽  
High Performance ◽  
High Strength ◽  
Strengthening Mechanisms ◽  
Particle Size Analyzer ◽  
Composition Analyzer ◽  
The Relationship

The effect of phosphogypsum (PG) modified on mechanical properties of super sulphate cement (SSC) was systematically studied in this paper. Then attentions and researches were focused on the relationship between specific surface (SSA) and the mechanical properties of SSC containing PG modified by calcining, floating, neutralizing with alkali. Strengthening mechanisms of SSC were further investigated and analyzed by laser particle size analyzer and chemical composition analyzer at last. Results showed that the high strength SSC with the compressive strength 35MPa at 7 days, over 60MPa at 28 days, and some even more than 70MPa at 56 days, could be successfully developed. This research can provide a key reference for the utilization of PG and development of high performance eco-SSC.

Preparation of Calcined Phosphogypsum-Based High-Strength Supersulphated Cement

2012 ◽  
Vol 188 ◽  
pp. 199-204 ◽  
Author(s):  
Yu Xin Gao ◽  
Bao Ying Yu ◽  
Fen Lian Xu ◽  
Xi Hua Lin ◽  
Shi Hai Yang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Electron Microscope ◽  
Chemical Composition ◽  
Setting Time ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Composition Analyzer ◽  
Scanning Electron ◽  
Curing Age

Based on mechanical properties, the influences of the clinker dosage(C1, C2, C3), calcination temperature(M1, M2, M3) of phosphogypsum(PG) and specific surface area(S1, S2, S3, S4) on the mechanical properties of supersulphated cement(SSC) were systematically studied; Then SSC with different kinds of PG were chose to research water requirement of normal consistency, setting time and soundness; Strengthening mechanism on SSC were further investigated and analyzed with scanning electron microscope(SEM) and chemical composition analyzer at last. Results showed SSC with conditions of C2, T3 and S3 has 36.4, 56.5 and 72.6MPa standard mortar compressive strength at 7d, 28d and 56d curing age. Calcined Phosphogypsum(CPG)-based high strength SSC is successfully developed.

scholarly journals Meta-Analysis of Fiber Impact on Mechanical Properties of Ultra-High Performance Concrete

2020 ◽  
Author(s):  
Faiq M. Al-Zwainy ◽  
Hussam k. Risan ◽  
Rana I. K. Zaki
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Meta Analysis ◽  
High Strength ◽  
Ultimate Compressive Strength ◽  
Ultra High Performance Concrete

The purpose of this study was to conduct a meta-analysis that shows the influence of fiber on ultimate compressive strength and tensile strength of ultra-high performance concrete. The internet scholarly search engines and ScienceDirect article references were used to illustrate the papers concerning the experimental investigations of mechanical properties of ultra-high strength concrete with and without fiber with clearly, completely and comparative raw data. The normal concrete test results were dismissed from this search. Seven trials were identified based on the adopted inclusion and exclusion criteria above. The meta-analysis based on standardized mean difference was carried out on the basis of a fixed-effects model for the major outcomes of the ultimate compressive and tensile properties of ultra-high performance concrete. A total of 888 test specimens were enrolled in these seven trials. The combined analysis yielded a sign of a significant improvement in ultimate compressive strength and tensile strength of ultra-high strength concrete with fiber addition of 2% by concrete volume. The summary effect size of ultimate compressive strength was 2.34 while a more improvement in term of tensile strength with effect size of 2.64. By addition fiber of 2% provides a significant benefit in mechanical properties of ultra-high performance concrete.

Influence of Metakaolin on Mechanical Properties of High-Performance Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1904-1909
Author(s):  
Bao Min Wang ◽  
Wei Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Equal Mass ◽  
Test Results ◽  
Optimum Temperature ◽  
Compressive Strength Of Concrete ◽  
And Performance

Kaolin is a material with broad sources and a low price. Metakaolin is made from kaolin which is calcined, finely ground at an optimum temperature of 750 being kept constant for 4 hours. High strength and performance concrete can be mixed from metakaolin as a substitute for equal mass cement. The influences of 5%, 10% and 15% metakaolin in substitution of equal cement masses were studied on the mechanical properties of high-performance concrete. The test results showed that the addition of metakaolin improved the cubic compressive strength, splitting tensile strength and flexural strength of HPC, among which the improvement in compressive strength was the most siginificant, and simultaneously, there was also an improvement in concrete toughness in a certain degree. The optimum content of metakaolin is 10% resulting in an increase of the cubic compressive strength of concrete by 8.3% correspondingly.

scholarly journals High Strength Geopolymers Produced from Coal Combustion Fly Ash

2013 ◽  
Vol 11 (2) ◽  
pp. 155-161
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Fly Ash ◽  
Coal Combustion ◽  
High Strength ◽  
Coarse Fraction ◽  
Strength Development ◽  
Fly Ashes ◽  
The Relationship ◽  
Geopolymer Material

High strength geopolymers were produced from coal combustion fly ashes. These matrices reached compressive strength values over 100 MPa, much stronger and denser than obtained by using Portland Cement binders. Size fractions were obtained by size separation techniques and the relationship between strength and particle size was investigated. The differences in compressive strength measured in the geopolymers made from fine fractions, the original fly ash and a coarse fraction of the same ash, were not significantly higher than the variation found for a reference geopolymer material. Therefore, a direct size-strength relationship could not be proven. Moreover, the chemistry and the pH of the fractions also varied, and this might as well has played a role in the strength development.

Utilization of Fly Ash in High Performance Floor Screed Based on Cement and its Influence on Physical Mechanical Properties

2016 ◽  
Vol 865 ◽  
pp. 201-205 ◽  
Author(s):  
Michaela Fiedlerová ◽  
Rostislav Drochytka ◽  
Pavel Dohnálek
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Bulk Density ◽  
High Performance ◽  
Power Plants ◽  
High Strength ◽  
Partial Replacement ◽  
Reference Samples

This paper deals with the evaluation of a partial replacement of cement by Czech fly ash in high strength floor screed in dosage of 10, 20, 30 and 40% and the assessment of the physical-mechanical properties such as compressive strength, water absorption and bulk density. Used fly ashes are from power plants Počerady, Opatovice and Tušimice. The experimental study showed that the use of Czech fly ash improves the compressive strength. The bulk density decreases and therefore water absorption increases. Reference samples become clearly the lowest compressive strength at age of 28 days (fc28). A significant increase in compressive strength (fc28) was observed in case of mix design with addition of 10% and 20% of fly ash Tušimice (10%ETU, 20%ETU) and 20% and 30% of fly ash Počerady (20%EPC, 30%EPC). The addition of 20% of fly ash Počerady (20%EPC) has noticeable influence on short-term compressive strength (measured at the age of 24 hours).

scholarly journals Ultrafine and High-Strength Silk Fibers Secreted by Bimolter Silkworms

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2537 ◽  
Author(s):  
Kaiyu Guo ◽  
Xiaolu Zhang ◽  
Zhaoming Dong ◽  
Yuhui Ni ◽  
Yuqing Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Strength ◽  
Silk Gland ◽  
X Ray Diffraction ◽  
Ultrafine Fibers ◽  
Silk Fibers ◽  
Warmth Retention ◽  
The Relationship ◽  
Β Sheet

Ultrafine fibers are widely employed because of their lightness, softness, and warmth retention. Although silkworm silk is one of the most applied natural silks, it is coarse and difficult to transform into ultrafine fibers. Thus, to obtain ultrafine high-performance silk fibers, we employed anti-juvenile hormones in this study to induce bimolter silkworms. We found that the bimolter cocoons were composed of densely packed thin fibers and small apertures, wherein the silk diameter was 54.9% less than that of trimolter silk. Further analysis revealed that the bimolter silk was cleaner and lighter than the control silk. In addition, it was stronger (739 MPa versus 497 MPa) and more stiffness (i.e., a higher Young’s modulus) than the trimolter silk. FTIR and X-ray diffraction results revealed that the excellent mechanical properties of bimolter silk can be attributed to the higher β-sheet content and crystallinity. Chitin staining of the anterior silk gland suggested that the lumen is narrower in bimolters, which may lead to the formation of greater numbers of β-sheet structures in the silk. Therefore, this study reveals the relationship between the structures and mechanical properties of bimolter silk and provides a valuable reference for producing high-strength and ultrafine silk fibers.

scholarly journals Experimental Analysis of the Mechanical Properties and Resistivity of Tectonic Coal Samples with Different Particle Sizes

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Coalbed Methane ◽  
Coal Sample ◽  
Fine Particles ◽  
Particle Sizes ◽  
Tectonic Coal

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.

scholarly journals Development of Novel Lightweight Al-Rich Quinary Medium-Entropy Alloys with High Strength and Ductility

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4223
Author(s):  
Po-Sung Chen ◽  
Yu-Chin Liao ◽  
Yen-Ting Lin ◽  
Pei-Hua Tsai ◽  
Jason S. C. Jang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Compressive Strain ◽  
High Strength ◽  
Fine Tuning ◽  
Face Centered Cubic ◽  
Transportation Industry ◽  
High Entropy ◽  
Good Potential ◽  
Face Centered

Most high-entropy alloys and medium-entropy alloys (MEAs) possess outstanding mechanical properties. In this study, a series of lightweight nonequiatomic Al50–Ti–Cr–Mn–V MEAs with a dual phase were produced through arc melting and drop casting. These cast alloys were composed of body-centered cubic and face-centered cubic phases. The density of all investigated MEAs was less than 5 g/cm3 in order to meet energy and transportation industry requirements. The effect of each element on the microstructure evolution and mechanical properties of these MEAs was investigated. All the MEAs demonstrated outstanding compressive strength, with no fractures observed after a compressive strain of 20%. Following the fine-tuning of the alloy composition, the Al50Ti20Cr10Mn15V5 MEA exhibited the most compressive strength (~1800 MPa) and ductility (~34%). A significant improvement in the mechanical compressive properties was achieved (strength of ~2000 MPa, strain of ~40%) after annealing (at 1000 °C for 0.5 h) and oil-quenching. With its extremely high specific compressive strength (452 MPa·g/cm3) and ductility, the lightweight Al50Ti20Cr10Mn15V5 MEA demonstrates good potential for energy or transportation applications in the future.

scholarly journals Properties of High-Strength Flowable Mortar Reinforced with Palm Fibers

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Test Results ◽  
Palm Fiber ◽  
Toughness Index ◽  
Strength And Toughness

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.

Size Effect on Mechanical Properties of LVL

2014 ◽  
Vol 887-888 ◽  
pp. 824-829
Author(s):  
Qing Fang Lv ◽  
Ji Hong Qin ◽  
Ran Zhu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Size Effect ◽  
Tensile Test ◽  
Compression Test ◽  
Test Results ◽  
Laminated Veneer Lumber ◽  
Object Of Study ◽  
The Relationship

Laminated veneer lumber is taken as an object of study, and use LVL specimens of different sizes for compression test and tensile test. The goal of the experiment is to investigate the size effect on compressive strength and tensile strength as well as the influence of the secondary glued laminated face, which appears in the secondary molding processes. The results show that both compressive strength and tensile strength have the size effect apparently and the existence of the secondary glued laminated face lower the compressive strength of LVL specimens. Afterwards, the relationship between compressive strength and volume along with tensile strength and area are obtained by the test results.

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