Influence of the Kind and the Shape of Insulating Materials on the Mechanical Properties of the Composites Plaster- Granular Cork and Plaster- Fiber Alpha

2021 ◽  
Vol 886 ◽  
pp. 241-255
Author(s):  
Youssef Maaloufa ◽  
Soumia Mounir ◽  
Khabbazi Abdelhamid ◽  
Khalid El Harrouni

The objective of our work is to study the influence of nature and the shape of the insulating materials on the mechanical performance of composites based on plaster. The study aims to increase the thermal performance of the building envelope and the same time maintains sufficient mechanical properties of the composites studied. Plaster was combined with two additives (alpha fiber and granular cork). A physical and mechanical characterization of the composites plaster-fiber alpha and plaster-cork was carried on. Authors obtained an important gain in term of lightness 27 % concerning the composite plaster-fiber alpha, however for the composite plaster-cork, the value is 34 %. Concerning the mechanical properties, authors found a decrease in flexural strength of 60 % for the plaster-cork, and an increase of 33 % for the plaster-alpha fiber. For the compressive strength, a reduce of 87 % for the plaster-alpha fiber and 80% for the plaster-cork was observed. Those finding are justified by the scanning microscopic electron tests which show the distribution of the two insulators and adhesion within the plaster matrix.

2019 ◽  
Vol 5 (5) ◽  
pp. 1007-1019 ◽  
Author(s):  
Babar Ali ◽  
Liaqat Ali Qureshi ◽  
Ali Raza ◽  
Muhammad Asad Nawaz ◽  
Safi Ur Rehman ◽  
...  

Despite plain cement concrete presenting inferior performance in tension and adverse environmental impacts, it is the most widely used construction material in the world. Consumption of fibers and recycled coarse aggregates (RCA) can add ductility and sustainability to concrete. In this research, two mix series (100%NCA, and 100%RCA) were prepared using four different dosages of GF (0%GF, 0.25%GF, 0.5%GF, and 0.75%GF by volume fraction).  Mechanical properties namely compressive strength, splitting tensile strength, and flexural strength of each concrete mixture was evaluated at the age of 28 days. The results of testing indicated that the addition of GF was very useful in enhancing the split tensile and flexural strength of both RCA and NCA concrete. Compressive strength was not highly sensitive to the addition of GF. The loss in strength that occurred due to the incorporation of RCA was reduced to a large extent upon the inclusion of GF. GF caused significant improvements in the split tensile and flexural strength of RCA concrete. Optimum dosage of GF was determined to be 0.25% for NCA, and 0.5% for RCA concrete respectively, based on the results of combined mechanical performance (MP).


2018 ◽  
Vol 37 (22) ◽  
pp. 1335-1345 ◽  
Author(s):  
Siddhartha Brahma ◽  
Vikas Patel ◽  
Selvum Pillay ◽  
Haibin Ning ◽  
Vinoy Thomas

The flexibility of processing PA6-based discontinuous carbon fiber panels using vacuum-assisted resin transfer molding was studied. The ease of incorporating various reinforcements namely baseline, tow in the center of preform, fabric in the center of preform and fabric on the outside as skin was investigated. Mechanical characterization was conducted on all the variations made. There was an average increase of about 3%, 20% and 47% in the tensile properties of tow in the center, fabric in the center and fabric on the outside as skin, respectively, as compared to the baseline. A similar increase in properties was noticed in its flexural and impact strength. The data showed a correlation between the mechanical properties and the total surface area of additional reinforcements used. As the surface area of the reinforcement increased, the mechanical properties increased as well. It also showed that reinforcements on the surface of the preform as a skin performed the best. DMA analysis showed the effect of reinforcement on the storage modulus and tan delta across temperatures ranging from 30°C to 150°C. SEM analysis showed that the fibers and the additional reinforcements were coated with PA6 which translated into consistent mechanical performance.


2015 ◽  
Vol 1119 ◽  
pp. 677-682
Author(s):  
Alessandra Dal Cin ◽  
Lorenzo Massaria ◽  
Enzo Siviero

The aim of this study is to evaluate the influence of SFRC repairs of different thicknesses on the mechanical performance of RC slabs, especially with respect to the crack pattern and level of cracking load. To understand the influence of SFRC, in terms of performance and variation of cracking load after repairing, a comparison with a reinforced concrete slab without fiber reinforcement was made. The study shows also the mechanical characterization of SFRC through conventional testing, to evaluate compressive strength, fracture energy, tensile strength and toughness. Concerning the application of SFRC on the concrete slab surface, the bond was improved by removing a small amount of superficial material. Finally, the experimental results on cracks distribution, displacements and level of cracking load are shown.


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.


2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2139
Author(s):  
Wei Shian Tey ◽  
Chao Cai ◽  
Kun Zhou

Multi Jet Fusion (MJF) is a recently developed polymeric powder bed fusion (PBF) additive manufacturing technique that has received considerable attention in the industrial and scientific community due to its ability to fabricate functional and complex polymeric parts efficiently. In this work, a systematic characterization of the physicochemical properties of MJF-certified polyamide 11 (PA11) and thermoplastic polyurethane (TPU) powder was conducted. The mechanical performance and print quality of the specimens printed using both powders were then evaluated. Both PA11 and TPU powders showed irregular morphology with sharp features and had broad particle size distribution, but such features did not impair their printability significantly. According to the DSC scans, the PA11 specimen exhibited two endothermic peaks, while the TPU specimen exhibited a broad endothermic peak (116–150 °C). The PA11 specimens possessed the highest tensile strength in the Z orientation, as opposed to the TPU specimens which possessed the lowest tensile strength along the same orientation. The flexural properties of the PA11 and TPU specimens displayed a similar anisotropy where the flexural strength was highest in the Z orientation and lowest in the X orientation. The porosity values of both the PA11 and the TPU specimens were observed to be the lowest in the Z orientation and highest in the X orientation, which was the opposite of the trend observed for the flexural strength of the specimens. The PA11 specimen possessed a low coefficient of friction (COF) of 0.13 and wear rate of 8.68 × 10−5 mm3/Nm as compared to the TPU specimen, which had a COF of 0.55 and wear rate of 0.012 mm3/Nm. The PA11 specimens generally had lower roughness values on their surfaces (Ra < 25 μm), while the TPU specimens had much rougher surfaces (Ra > 40 μm). This investigation aims to uncover and explain phenomena that are unique to the MJF process of PA11 and TPU while also serving as a benchmark against similar polymeric parts printed using other PBF processes.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli

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.


2011 ◽  
Vol 477 ◽  
pp. 290-295 ◽  
Author(s):  
Li Bo Bian ◽  
Shao Min Song

Considering large number production of the abandoned tyres and the question of the concrete with mixture of crumb rubber,the mainly task of this paper is to study the mechanical properties of different mixing ratio concrete with vary volume of crumb rubber. The results showed that the workability, apparent density, compressive strength, flexural strength and brittleness index decrease as the increase of crumb rubber. While the anti-crack performance and anti-fatigue performance can be improved. The wear-resistance properties are a little lower than common concrete.


2021 ◽  
Vol 903 ◽  
pp. 11-16
Author(s):  
M.A. Manjunath ◽  
K. Naveen ◽  
Prakash Vinod ◽  
N. Balashanmugam ◽  
M.R. Shankar

Polymethyl methacrylate (PMMA) is one among few known photo-polymeric resin useful in lithography for fabricating structures having better mechanical properties to meet the requirement in electronics and biomedical applications. This study explores the effect of Photo Initiator (PI) concentration and also curing time on strength and hardness of Polymethyl methacrylate (PMMA) obtained by UV photopolymerization of Methyl methacrylate (MMA) monomer. The UV LED light source operating at the wavelength of 364 nm is used with Benzoin Ethyl Ether (BEE) as photo initiator. The curing of PMMA resin is supported with peltier cooling device placed at the bottom of the UV light source. The characterisation study of UV photo cured PMMA is analysed through nano indenter (Agilent Technologies-G200). The current work investigates the influence of PI concentration and curing time in achieving maximum mechanical properties for UV photopolymerized PMMA.


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.


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