Graphene Additives Effect on Mechanical and Structural Characterization Properties of Polyvinyl Alcohol (PVA) and Boron Based Cement Mortar

2020 ◽  
Vol 12 (2) ◽  
pp. 269-275
Author(s):  
Hakan Çağlar ◽  
Arzu Çağlar ◽  
Ömer Can

In this study, it was aimed to develop properties of cement paste having standard properties and produce a graphene doped Polyvinyl Alcohol (PVA) and boron-based cement paste in this context. This type of special cement is mixed with PVA as polymer additive material so it can have a higher strength and sufficient elasticity per unit weight. Also, boric acid which can absorb neutrons having poisonous effect in nuclear reactions is added into the cement in order to minimize environmental disaster caused by a nuclear accident. Compressive and bending strengths were measured based on TSE tests of graphene doped PVA and boron-based cement paste. Then, samples were measured by Brunauer-Emmett-Teller Method (BET) and subjected to X-ray Diffraction (XRD). In XRD measurements, crystalline structure was observed in all materials. According to compressive strength tests, as the graphene amount increases compressive strength also increases, however in bending strength tests as the graphene amount increases bending strength decreases. Although the values of bending strength of samples produced decreased with increase of graphene content, these values were found to be above the standard values. In addition to boron, graphene admixture has a significant effect on material with its positive strength properties.

2018 ◽  
Vol 7 (2.12) ◽  
pp. 406
Author(s):  
L Krishnaraj ◽  
P T. Ravichandran ◽  
Shaik AarifIlahi ◽  
V Ramanathan

The strength of cement paste and aggregate components helps to decide the strength of the concrete, their properties of deformation, and the binding properties among the aggregate surface and cement paste. It is conceivable with many of the aggregates to form high strength concrete by increasing the cement paste strength, which can be controlled by choosing of water-content ratio and type of admixture dosage. The current scenario in the concrete technology and the accessibility of many kind of mineral and chemical admixtures, and special super plasticizer to gain the targeted compressive strength of a concrete. In this study MYK Remicrete PC30 and BASF Master Glennium ACE 30 were utilized as the admixtures as Add 1 and Add 2 which acts as high rate water reducing agents. These developments have led to increase uses of Rapid strength concrete. To compare the mechanical and durability properties of concrete using Fly ash and Admixtures the following tests were conducted on concrete tests specimens. Mechanical tests are to be conducted such as compressive strength tests, and tensile strength tests, durability tests like water absorption test, acid test by HCL, H2SO4 and HNO3. The result indicates that rate of development of compressive strength and tensile strength are higher for the concrete design mix which has HRWR admixture of 1% and FA of 20%.  


2011 ◽  
Vol 99-100 ◽  
pp. 692-695
Author(s):  
Tie Quan Ni ◽  
Li Zhang ◽  
Bing Yuan

The influence of wollastonite or plant fiber on the property of autoclaved cement concrete is studied by chemical composition analysis, X-ray diffraction analysis, scanning electron microscopy and energy spectrum analysis. The results showed that the two fibers were benefit to bending strength of autoclaved cement concrete. The suitable content of wollastonite was about 15% of cement mass, and the increased amplitude of flexural strength was more than 30% and the compressive strength slightly increased for autoclaved cement concrete admixed wollastonite. The optimal content of plant fiber was about 1.5% of cement mass, the increased amplitude of the flexural strength was more than 20%, and the compressive strength change of autoclaved cement concrete was not significant for autoclaved cement concrete admixed plant fiber.


2019 ◽  
Vol 5 (3) ◽  
pp. 80
Author(s):  
Hasan Selim Şengel ◽  
Mehmet Canbaz ◽  
Ersin Güler

Khorasan mortar was used in almost all of the historical structures in the geographical area of turkey. It is still used in the renovation of these structures. Water, lime, baked clay is used in the production of Khorasan by breaking and grinding. Crushed brick and tiles are preferred as baked clay. In this study, the usability of ceramic wastes as baked clay was investigated. An important part of ceramic production is made especially in Eskişehir and its vicinity. 10% of ceramic production shows up as wastes because of various reasons. These wastes which are under 20 mm are crushed in the jaw breakers and these which are under 150 mm are grinned in grinders, transformed to powder and then mixed with hydrated lime and water in various proportions, in this way Khorasan mortars are obtained. In mortar production, crushed ceramic-ceramic powder ratio, ceramic-lime ratio were changed and the most suitable ratios were tried to be found. Samples taken from these mortars which are 4 cm x 4 cm x 16 cm in size are removed after a day from the mold and kept in humid environment. Physical and mechanical properties such as unit weight, ultrasonic pulse velocity, bending strength, compressive strength of the mortar were determined. As a result of the experiments, the unit weights range was between 1.5–1.65 kg/dm3, the ultrasonic pulse velocity rates range from 1.3–1.9 km/h, the range of bending strengths was from 0.25–1.05 MPa, and compressive strength has changed in the range of 7.5–10.5 MPa. With the work done, it is recommended to use a high percentage of lime while using ceramic wastes in the process of producing Khorasan mortar.


2015 ◽  
Vol 659 ◽  
pp. 164-168
Author(s):  
Pongsak Jittabut ◽  
Prinya Chindaprasirt ◽  
Supree Pinitsoontorn

This research was presented the physical and thermal conductivity properties of cement pastes containing nanosilica by mixing three nanosilica particle sizes of 12, 50 and 150 nm, using nanosilica of 1-5 wt%. The water-cementitious ratio (W/C) was 0.5 for all samples. Thermal property coefficients were tested using a direct measuring instrument with surface probe (ISOMET2114). The influence of nanosilica on the physical properties were compressive strength, bulk density, XRD and SEM respectively. The results indicated that the use of nanosilica as an admixture can reduce the thermal conductivity and lowered the bulk density of specimen. The cement paste with nanosilica particle size of 50 nm with 4 wt% nanosilica at the age of 28 days showed the optimized properties. The thermal conductivity was lowest at 0.913 W/m-K, the compressive strength was highest at 51.62 MPa and the bulk density was 1,806 kg/m3respectively. The compressive strength increases more than 50% higher than that of pure paste. The cement pastes with nanosilica particle sizes of 50 and 150 nm, have lower unit weight and thermal conductivity than typical control cement paste about 9% and 15% respectively. The nanosilica mixed cement paste is very interesting for energy saving when used as wall insulating material.


Mechanik ◽  
2022 ◽  
Vol 95 (1) ◽  
pp. 12-14
Author(s):  
Mateusz Rudnik

The article presents the results of compressive strength tests of cylindrical samples with a hexagonal cell structure. The samples were made of MED 610 material using the photo-curing technology liquid polymer resins. The compressive strength was estimated on the basis of a static compression test of the printed elements. It has been shown that the PolyJet Matrix 3D printing technology enables the printing models with a thin-walled cell structure, which, while maintaining the appropriate strength properties, can be used in the design and production of certain utility models.


Author(s):  
Mohamad Hanafi ◽  
Ertug Aydin ◽  
Abdullah Ekinci

Extinction of natural resources builds up pressure on governments to invest in research to find more sustainable resources for construction sector. Earlier studies on mortar and concrete show that bottom ash and basalt fiber are independently alternative binder in the concrete sector. This study aims to use bottom ash and basalt fiber blends as alternative novel-based composites in pure cement paste. Strength and durability properties of two different percentages of bottom ash (40% and 50%) and three volume fractions of basalt fiber (0.3%, 0.75%, and 1.5%) were used at three curing periods (7, 28, and 56 days). In order to measure physical properties of the basalt-reinforced bottom ash cement paste composites flowability, dry unit weight, porosity and water absorption measurements at 7, 28, and 56 days of curing were performed. Furthermore, mechanical properties of composites determined by unconfined compressive strength and flexural strength tests. Finally, to assess the durability sulfate-resistance and seawater-resistance tests have been performed on composites at 28 and 56 days of curing. Results showed that addition of basalt fiber improves physical, mechanical and chemical stability properties of paste up to a limiting basalt fiber addition (0.3% volume fraction) where above an adverse effect have been monitored. It is clear that observed results can lead to development of sustainability strategies in the concrete industry by utilizing bottom ash and basalt fiber as an alternative binder.


2021 ◽  
Vol 7 (5) ◽  
pp. 857-865
Author(s):  
Ahmed I. Ghazal ◽  
Mohammed Y. El-Sheikh ◽  
Ahmed H. Abd El-Rahim

Water is one of the main constituents of concrete. Although many types of water exist, fresh water is the mostly used in concrete industry. Fresh water is expected to be in a great shortage by 2050 according to UN world water development report. Incorporating seawater in concrete mixture can help in the expected problem of scarcity of fresh water. Also, in many cases seawater may be the only available water especially in coastal regions. Many reports mention various possibilities of using seawater in concrete without detrimental effect on concrete properties. In this study another beneficial effect of seawater over tap water was concluded. Setting tests of cement paste mixed with seawater was determined using Vicat apparatus and compared to tap water. Compressive strength tests at the age of 28 days of Portland cement concretes with varied quantity of cement i.e. 300, 350, 400, 450, and 500 kg, and mixed with seawater was also performed and compared to tap water. The results show that seawater affects standard consistency of cement paste and two percent increase was required in order to attain the same consistency as tap water. It shows also seawater slightly accelerates initial setting of cement but the effect is not so pronounced so as to cause a trouble in concrete and final setting time almost remains unaltered. Compressive strength tests show an increase in concrete strength mixed with seawater for all tested mixtures and depending on quantity of cement. It also shows a beneficial effect of seawater on compressive strength of rich concrete with quantity of cement 450 and 500 kg over tap water. Doi: 10.28991/cej-2021-03091695 Full Text: PDF


2019 ◽  
Vol 42 ◽  
pp. e44764
Author(s):  
Gissele Souza Rocha ◽  
Claudio Henrique de Carvalho Silva ◽  
Heraldo Nunes Pitanga ◽  
Ecidinéia Pinto Soares de Mendonça ◽  
Dario Cardoso de Lima ◽  
...  

The main objective of this study was to propose the application of soil-lime mixtures asa primary coating layerof unpavedforestroads based on the premise that this layer can be considered mechanically similar to a flexible pavementsub base layer, aiming to fill a gap in the current technical literature and engineering practice in this field of knowledge. In the study, a laboratory test program was carried out in a residual gneiss soil encompassing: (i) geotechnical characterization tests; (ii) compaction tests at the standard Proctor energy on soil specimens and on soil-lime mixturespecimens prepared with lime contents of 2, 4 and 6% related to the dry soil mass; (iii) unconfined compressive strength tests on soil specimens compacted at the standard Proctor optimum parameters; and (iv) unconfined compressive strength tests on specimens of soil-lime mixtures compacted at the standard Proctor optimum compaction parameters with lime contents of 2, 4 and 6%, and cured at 22.8°C in the curing periods of 3, 7, 28 and 90 days. The results showed that the addition of lime resulted in: (i) reduction in soil maximum dry unit weight (gdmax) and increase in soil optimum water content (wopt);and(ii) significant gains in soil unconfined compressive strength that evidenced the expressive occurrence of pozzolanic reactions in the mixtures.Based on the hypothesis of a similar requirement for soil-cement and soil-lime mixtures, the tested soil-lime mixtures met the minimum mechanical strength (1.2MPa) required for application as a primary coating layer of unpaved forest roads.


2017 ◽  
Vol 748 ◽  
pp. 295-300 ◽  
Author(s):  
Rui Shuang Jiang ◽  
Bao Min Wang

In this work, two type graphene were dispersed in aqueous solution via sonication, and graphene nanoplatelets (GP) and graphene oxide (GO) were characterized by means of ultraviolet visible spectroscopy (UV-vis), X-ray diffraction (XRD) and transmission electron microscopy (TEM). In addition, the effects of different graphene (GP and GO) on mechanical properties and microstructure of cement-based materials were investigated via filed emission scanning electron microscopy (FESEM). The results suggested that the incorporation of GP and GO both improved the flexural and compressive strength of cement, and the GP had a more prominent impact on the strengths of cement, compared with GO. The flexural and compressive strength of cement increased up to 23.5% and 7.5% with 0.05 wt% GP, respectively. FESEM analysis indicated that the microstructure of GP-cement paste was similar to that of control sample without graphene, whereas, a few flower-like crystals were generated in GO-cement paste. This work could provide a new understanding for further researches of graphene-cement composites.


2015 ◽  
Vol 815 ◽  
pp. 177-181 ◽  
Author(s):  
Mohd Mustafa Al Bakri Abdullah ◽  
Mukridz Md Mohtar ◽  
Liew Yun Ming ◽  
Muhammad Faheem Mohd Tahir ◽  
Kamarudin Husin ◽  
...  

This paper studies the effect of curing temperature and curing duration to the flood mud based geopolymer on compressive strength properties. Flood mud was used as a raw material for geopolymer and geopolymer samples were synthesized by using sodium silicate and sodium hydroxide 14M solution. These samples were cured at different temperature (100°C, 150°C, 200°C and 250°) for different curing duration (6h, 12h and 24h) respectively. Compressive strength tests were carried out at after 28 days. The compressive strength and SEM analysis of geopolymer products were evaluated. Result showed that the maximum compressive strength was 24 MPa at temperature of 150°C for 24 hours. With increasing ageing day, densification of geopolymer gel was observed.


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