scholarly journals Investigation of Mechanical and Durability Properties of Concrete Mixed with Water Exposed to a Magnetic Field

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
R. Dharmaraj ◽  
G. K. Arunvivek ◽  
Alagar Karthick ◽  
V. Mohanavel ◽  
Bhagavathi Perumal ◽  
...  

Water is a crucial element in the concrete mix and is alone responsible for concrete work ability and cement hydration. The massive quantity of potable water consumed during the production of concrete is a concern. In general, fresh and hard concrete qualities are most influenced by the quantity and water quality. The use of magnetic water in concrete gives many benefits when it comes to increasing its properties. A substantial quantity of water can be saved by substituting potable water with magnetized water in concrete. In this study, the effects of magnetized water on the concrete's mechanical and durability properties were tested. Four different combinations were made using potable water and magnetic water. Mechanical properties including compression, flexural, tensile strength, and SEM analysis were evaluated. Water absorption, acid resistance, and corrosion resistance were all tested as part of the durability tests. According to the results of the experiments, employing magnetic water for concrete preparation and curing enhanced the mechanical properties and durability. Concrete mix MMMC prepared and subjected to curing using magnetized water has a 14.86% greater compressive strength than ordinary concrete. Similarly, tensile and flexural strength of mix MMMC amplified to 14.32% and 14.02%, respectively. Besides, the consumption of chemical admixtures also considerably reduced in magnetized water imbibed concrete.

2021 ◽  
Vol 7 ◽  
Author(s):  
D. Ali ◽  
U. Sharma ◽  
R. Singh ◽  
L. P. Singh

In the present study, the mechanical and durability properties of silica nanoparticle (SNP)-incorporated fly ash (FA) concrete mix were examined after 365 days of exposure. The dosages of FA replaced by cement in the present study were 30%, 40%, and 50%, while 3% SNPs were added by the weight of cement in the FA incorporated mix. For a comparison of SNPs with silica fume (SF), 6% SF was added (by the weight of cement) and entire casting was performed at a constant water to binder (w/b) ratio of 0.29. The present work is the extension of a previous study wherein durability properties of the same mixes were reported for up to 180 days of exposure. Compressive strength results show that in the presence of SNPs, the enhancement in compressive strength was in the range of 10–14%, while, in presence of SF, 8–10% of the enhancement was observed as compared to control. However, exposed samples in a carbonation environment showed that the compressive strength of the control and SF incorporated mix increased, while SNP-incorporated samples showed negligible enhancement. Further, sulphate exposed mix show that compressive strength decreases, however, the SNP-incorporated mix showed the lowest reduction compared to other mixes. Therefore, the study shows that the SNP-incorporated mix has higher mechanical properties and more durability compared to other mixes in a severe environment.


2021 ◽  
Vol 13 (8) ◽  
pp. 4546
Author(s):  
Kaiyue Zhao ◽  
Peng Zhang ◽  
Bing Wang ◽  
Yupeng Tian ◽  
Shanbin Xue ◽  
...  

Cement-based materials prepared with activated water induced by a magnetic field or electric field represent a possible solution to environmental issues caused by the worldwide utilization of chemical admixtures. In this contribution, electric- and magnetic-activated water have been produced. The workability and mechanical properties of cement mortar prepared with this activated water have been investigated. The results indicate that the pH and absorbance (Abs) values of the water varied as the electric and magnetic field changed, and their values increased significantly, exhibiting improved activity compared with that of the untreated water. In addition, activated water still retains activity within 30 min of the resting time. The fluidity of the cement paste prepared with electric-activated water was significantly larger than that of the untreated paste. However, the level of improvement differed with the worst performance resulting from cement paste prepared with alternating voltage activated water. In terms of mechanical properties, both compressive strength and flexural strength obtained its maximum values at 280 mT with two processing cycles. The compressive strength increased 26% as the curing time increased from 7 days to 28 days and flexural strength increased by 31%. In addition, through the introduction of magnetic-activated water into cement mortar, the mechanical strength can be maintained without losing its workability when the amount of cement is reduced.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2636
Author(s):  
Petr Valášek ◽  
Miroslav Müller ◽  
Vladimír Šleger ◽  
Viktor Kolář ◽  
Monika Hromasová ◽  
...  

Composite materials with natural fillers have been increasingly used as an alternative to synthetically produced materials. This trend is visible from a representation of polymeric composites with natural cellulose fibers in the automotive industry of the European Union. This trend is entirely logical, owing to a preference for renewable resources. The experimental program itself follows pronounced hypotheses and focuses on a description of the mechanical properties of untreated and alkali-treated natural vegetable fibers, coconut and abaca fibers. These fibers have great potential for use in composite materials. The results and discussion sections contribute to an introduction of an individual methodology for mechanical property assessment of cellulose fibers, and allows for a clear definition of an optimal process of alkalization dependent on the content of hemicellulose and lignin in vegetable fibers. The aim of this research was to investigate the influence of alkali treatment on the surface microstructure and tensile properties of coir and abaca fibers. These fibers were immersed into a 5% solution of NaOH at laboratory temperature for a time interval of 30 min, 1 h, 2 h, 3 h, 6 h, 12 h, 24 h, and 48 h, rinsed and dried. The fiber surface microstructures before and after the alkali treatment were evaluated by SEM (scanning electron microscopy). SEM analysis showed that the alkali treatment in the NaOH solution led to a gradual connective material removal from the fiber surface. The effect of the alkali is evident from the visible changes on the surface of the fibers.


2021 ◽  
Vol 5 (2) ◽  
pp. 48
Author(s):  
Yuxuan Wang ◽  
Yuke Zhong ◽  
Qifeng Shi ◽  
Sen Guo

Thermoplastic starch/butyl glycol ester copolymer/polylactic acid (TPS/PBSA/PLA) biodegradable composites were prepared by melt-mixing. The structure, microstructure, mechanical properties and heat resistance of the TPS/PBSA/PLA composites were studied by Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), tensile test and thermogravimetry tests, respectively. The results showed that PBSA or PLA could bind to TPS by hydrogen bonding. SEM analysis showed that the composite represents an excellent dispersion and satisfied two-phase compatibility when the PLA, TPS and PBSA blended by a mass ration of 10, 30, and 60. The mechanical properties and the heat resistance of TPS/PBSA/PLA composite were improved by adding PLA with content less than 10%, according to the testing results.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1473
Author(s):  
Jun Zhao ◽  
Kang Wang ◽  
Shuaibin Wang ◽  
Zike Wang ◽  
Zhaohui Yang ◽  
...  

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.


2020 ◽  
Vol 12 (8) ◽  
pp. 3154 ◽  
Author(s):  
Hedelvan Emerson Fardin ◽  
Adriana Goulart dos Santos

This research aimed to investigate the mechanical and physical properties of Roller Compacted Concrete (RCC) used with Recycled Concrete Aggregate (RCA) as a replacement for natural coarse aggregate. The maximum dry density method was adopted to prepare RCC mixtures with 200 kg/m³ of cement content and coarse natural aggregates in the concrete mixture. Four RCC mixtures were produced from different RCA incorporation ratios (0%, 5%, 15%, and 30%). The compaction test, compressive strength, splitting tensile strength, flexural tensile strength, and modulus of elasticity, porosity, density, and water absorption tests were performed to analyze the mechanical and physical properties of the mixtures. One-way Analysis of Variance (ANOVA) was used to identify the influences of RCA on RCC’s mechanical properties. As RCA increased in mixtures, some mechanical properties were observed to decrease, such as modulus of elasticity, but the same was not observed in the splitting tensile strength. All RCCs displayed compressive strength greater than 15.0 MPa at 28 days, splitting tensile strength above 1.9 MPa, flexural tensile strength above 2.9 MPa, and modulus of elasticity above 19.0 GPa. According to Brazilian standards, the RCA added to RCC could be used for base layers.


2010 ◽  
Vol 177 ◽  
pp. 447-450 ◽  
Author(s):  
Xin Zhang ◽  
Yi Wen Hu ◽  
Yin Wu ◽  
Wen Jie Si

The purpose of this study was to evaluate the crystal phase formation behavior and its influence on the mechanical properties of LiO2-SiO2-P2O5 glass-ceramics system. High temperature XRD was used to analyze the crystal phase formation in situ. The crystalline phases in the material both before and after heat-treatment were also analyzed. The flexural strength was measured by three-point bending test according to ISO 6872:2008(E). The SEM analysis showed that the high strength of the glass-ceramics is attributed to the continuous interlocking microstructure with fine lithium disilicate crystallines.


2022 ◽  
Author(s):  
Sunita Kumari ◽  
Dhirendra Singhal ◽  
Rinku Walia ◽  
Ajay Rathee

Abstract The present project proposes to utilize rice husk and maize cob husk ash in the cement to mitigate the adverse impact of cement on environment and to enhance the disposal of waste in a sustainable manner. Ternary concrete / MR concrete was prepared by using rise husk and maize cob ash with cement. For the present project, five concrete mixes MR-0 (Control mix), MR-1 (Rice husk ash 10% and MR-2.5%), MR-2 (Rice husk ash 10% and MR-5%), MR-3 (Rice husk ash 10% and MR-2.5%), MR-4 (Rice husk ash 10% and MR-2.5%) were prepared. M35 concrete mix was designed as per IS 10262:2009 for low slump values 0-25mm. The purpose is to find the optimum replacement level of cement in M35 grade ternary concrete for I – Shaped paver blocks.In order to study the effects of these additions, micro-structural and structural properties test of concretes have been conducted. The crystalline properties of control mix and modified concrete are analyzed by Fourier Transform Infrared Spectroscope (FTIR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). The results indicated that 10% Rice husk ash and 5% maize cob ash replaced with cement produce a desirable quality of ternary concrete mix having good compressive strength. The results of SEM analysis indicated that the morphology of both concrete were different, showing porous structure at 7 days age and become unsymmetrical with the addition of ashes. After 28 day age, the control mix contained more quantity of ettringite and became denser than ternary concrete. XRD analysis revealed the presence of portlandite in large quantity in controlled mix concrete while MR concrete had the partially hydrated particle of alite.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wasim Barham ◽  
Ammar AL-Maabreh ◽  
Omar Latayfeh

PurposeThe influence of using magnetic water instead of tap water in the mechanical properties of the concrete exposed to elevated temperatures was investigated. Two concrete mixes were used and cast with the same ingredients. Tap water was used in the first mix and magnetic water was used in the second mix. A total of 48 specimens were cast and divided as follows: 16 cylinders for the concrete compressive strength test (8 samples for each mix), 16 cylinders for the splitting tensile strength (8 specimens for each mix) and 16 beams to test the influences of magnetized water on the flexural strength of concrete (8 specimens for each mixture). Specimens were exposed to temperatures of (25 °C, 200 °C, 400 °C and 600 °C). The experimental results showed that magnetic water highly affected the mechanical properties of concrete. Specimens cast and curried out with magnetic water show higher compressive strength, splitting tensile strength and flexural strength compared to normal water specimens at all temperatures. The relative strength range between the two types of water used was 110–123% for compressive strength and 110–133% for splitting strength. For the center point loading test, the relative flexural strength range was 118–140%. The use of magnetic water in mixing concrete contribute to a more complete hydration process.Design/methodology/approachExperimental study was carried out on two concrete mixes to investigate the effect of magnetic water. Mix#1 used normal water as the mixing water, and Mix#2 used magnetic water instead of normal water. After 28 days, all the samples were taken out of the tank and left to dry for seven days, then they were divided into different groups. Each group was exposed to a different temperature where it was placed in a large oven for two hours. Three different tests were carried out on the samples, these tests were concrete compressive strength, flexural strength and splitting tensile strength.FindingsExposure of concrete to high temperatures had a significant influence on concrete mechanical properties. Specimens prepared using magnetic water showed higher compressive strength at all temperature levels. The use of magnetic water in casting and curing concrete can increase the compressive strength by 23%. Specimens prepared using magnetic water show higher splitting tensile strength at all temperatures up to 33%. The use of magnetic water in casting and curing can strengthen and increase concrete resistance to high temperatures, a significant enhancement in flexural strength at all temperatures was found with a value up to 40%.Originality/valuePrevious research proved the advantages of using magnetic water for improving the mechanical properties of concrete under normal conditions. The potential of using magnetic water in the concrete industry in the future requires conducting extensive research to study the behavior of magnetized concrete under severe conditions to which concrete structures may be subjected to. These days, there are attempts to obtain stronger concrete with high resistance to harsh environmental conditions without adding new costly ingredients to its main mixture. No research has been carried out to investigate the effect of magnetic water on the mechanical properties of concrete exposed to elevated temperature. The main objective of this study is to evaluate the effect of using magnetic water on the mechanical properties of hardened concrete subjected to elevated temperature.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
J. Sahari ◽  
M. A. Maleque

The mechanical properties of oil palm shell (OPS) composites were investigated with different volume fraction of OPS such as 0%, 10%, 20%, and 30% using unsaturated polyester (UPE) as a matrix. The results presented that the tensile strength and tensile modulus of the UPE/OPS composites increased as the OPS loading increased. The highest tensile modulus of UPE/OPS was obtained at 30 vol% of OPS with the value of 8.50 GPa. The tensile strength of the composites was 1.15, 1.17, and 1.18 times higher than the pure UPE matrix for 10, 20, and 30 vol% of OPS, respectively. The FTIR spectra showed the change of functional group of composites with different volume fractions of OPS. SEM analysis shows the filler pull-out present in the composites which proved the poor filler-matrix interfacial bonding.


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