Journal articles: 'Cement composite'

1

Cui, Xu, Chengcheng Huang, Meng Zhang, Changshun Ruan, Songlin Peng, Li Li, Wenlong Liu, et al. "Enhanced osteointegration of poly(methylmethacrylate) bone cements by incorporating strontium-containing borate bioactive glass." Journal of The Royal Society Interface 14, no. 131 (June 2017): 20161057. http://dx.doi.org/10.1098/rsif.2016.1057.

Full text

Abstract:

Although poly(methylmethacrylate) (PMMA) cements are widely used in orthopaedics, they have numerous drawbacks. This study aimed to improve their bioactivity and osseointegration by incorporating strontium-containing borate bioactive glass (SrBG) as the reinforcement phase and bioactive filler of PMMA cement. The prepared SrBG/PMMA composite cements showed significantly decreased polymerization temperature when compared with PMMA and retained properties of appropriate setting time and high mechanical strength. The bioactivity of SrBG/PMMA composite cements was confirmed in vitro , evidenced by ion release (Ca, P, B and Sr) from SrBG particles. The cellular responses of MC3T3-E1 cells in vitro demonstrated that SrBG incorporation could promote adhesion, migration, proliferation and collagen secretion of cells. Furthermore, our in vivo investigation revealed that SrBG/PMMA composite cements presented better osseointegration than PMMA bone cement. SrBG in the composite cement could stimulate new-bone formation around the interface between the composite cement and host bone at eight and 12 weeks post-implantation, whereas PMMA bone cement only stimulated development of an intervening connective tissue layer. Consequently, the SrBG/PMMA composite cement may be a better alternative to PMMA cement in clinical applications and has promising orthopaedic applications by minimal invasive surgery.

APA, Harvard, Vancouver, ISO, and other styles

2

Čáchová, Monika, Eva Vejmelková, Kateřina Šestáková, Pavel Reiterman, Martin Keppert, Dana Koňáková, and Robert Černý. "Basic Physical and Mechanical Properties of Composites Based on Three Different Cements." Key Engineering Materials 677 (January 2016): 186–90. http://dx.doi.org/10.4028/www.scientific.net/kem.677.186.

Full text

Abstract:

This article is focused on cement based composites. Two cements differing in mineralogical composition are utilised as main binder in composites mixtures. Results of measured physical parameters of studied materials are presented. For the sake of comparison, a reference material with Portland cement was also prepared. Basic physical properties (measured by water vacuum saturation method and by helium pycnometry), characterizations of pore system (determined by mercury porosimetry) and mechanical properties are the matter of this study. Composites show various open porosity; the results of open porosity of materials containing special cements show higher values, in comparison with composite based on Portland cement. This fact of course influences other material characteristics - mainly mechanical properties.

APA, Harvard, Vancouver, ISO, and other styles

3

Hancharoen, Kanokon, Parames Kamhangrittirong, and Pimsiree Suwanna. "Enhancement of Thermal and Sound Insulation Properties of Cement Composite Roofing Tile by Addition of Nanocellulose Coated Pineapple Fiber and Modified Rubber Tire Waste." Key Engineering Materials 861 (September 2020): 465–72. http://dx.doi.org/10.4028/www.scientific.net/kem.861.465.

Full text

Abstract:

In this work, the enhancement of thermal and sound insulation properties of cement composite roofing tile with nanocellulose coated pineapple fiber and modified waste tire rubber is studied. The composite was composed of bacterial nanocellose (BNC) coated pineapple fibers, modified rubber particles, platicizer and type I Portland cement in the weight ratio of 10:50:0.8:100 with the water to cement ratio (w/c) of 0.5. The thermal conducitity of the fiber rubber cement composite could be reduced to 0.1080 ± 0.0048 W/m.K as opposed to 0.3810 ± 0.0041 and 0.5860 ± 0.0050 W/m.K for the fiber cement and the rubber cement composites, respectively. Moreover, the noise reduction coefficient of the fiber rubber cement composite could be increased to 0.2832 as opposed to 0.2143 and 0.1899 for the fiber cement and the rubber cement composites, respectively. These results revealed that adding nanocellulose coated pineapple fiber and modified rubber particles together to the cement composite can enhance the thermal insulation and sound absorption abilities of the composite roof tile significantly better than adding each constituent separately.

APA, Harvard, Vancouver, ISO, and other styles

4

Cheng, Qiangqiang, Jixiong Zhang, Nan Zhou, Yu Guo, and Shining Pan. "Experimental Study on Unconfined Compression Strength of Polypropylene Fiber Reinforced Composite Cemented Clay." Crystals 10, no. 4 (March 26, 2020): 247. http://dx.doi.org/10.3390/cryst10040247.

Full text

Abstract:

The effects of three main factors, including polypropylene fiber content, composite cement content and curing time on the unconfined compressive strength of fiber-reinforced cemented clay were studied through a series of unconfined compressive strength tests. The experimental results show that the incorporation of fibers can increase the compressive strength and residual strength of cement-reinforced clay as well as the corresponding axial strain when the stress peak is reached compared with cement-reinforced clay. The compressive strength of fiber-reinforced cement clay decreases first, then increases with small-composite cement at curing time 14 d and 28 d. However, fiber-reinforced cement clay’s strength increases with the increase of fiber content for heavy-composite cement. The compressive strength of fiber-composite cement-reinforced marine clay increases with the increase of curing time and composite cement content. The growth rate increases with the increase of curing time. The failure mode of composite cement-reinforced clay is brittle failure, while the failure mode of fiber-reinforced cemented clay is plastic failure.

APA, Harvard, Vancouver, ISO, and other styles

5

Ni, Zhuo, Xue Xiao Du, Shuai Wang, Feng Xing, and Zhan Huang. "Effect of UF/Epoxy Microcapsules on Cement Composite." Advanced Materials Research 443-444 (January 2012): 700–704. http://dx.doi.org/10.4028/www.scientific.net/amr.443-444.700.

Full text

Abstract:

Effect of microcapsules on cement composites has been studied. The hydration of cement composite using microcapsules is studied by XRD and thermal techniques, showing that the addition of microcapsules has little affect on the hydration of cement. The pore size distribution and surface area of the cement composite with microcapsule are analyzed, showing a reduction in the pore content of cement composite and makes the pores smaller, which would improve durability and impermeability for designed materials. Damaging on cement and composites containing microcapsules and self-healing of these damagings can be reflected by the changes in their bending strength. When the cracks were generated in the composite, the microcapsules can release adhesive to fill in the space between the crackings, preventing cracking further growth.

APA, Harvard, Vancouver, ISO, and other styles

6

Aghyarian, Shant, Lucas C. Rodriguez, Jonathan Chari, Elizabeth Bentley, Victor Kosmopoulos, Isador H. Lieberman, and Danieli C. Rodrigues. "Characterization of a new composite PMMA-HA/Brushite bone cement for spinal augmentation." Journal of Biomaterials Applications 29, no. 5 (August 1, 2014): 688–98. http://dx.doi.org/10.1177/0885328214544770.

Full text

Abstract:

Calcium phosphate fillers have been shown to increase cement osteoconductivity, but have caused drawbacks in cement properties. Hydroxyapatite and Brushite were introduced in an acrylic two-solution cement at varying concentrations. Novel composite bone cements were developed and characterized using rheology, injectability, and mechanical tests. It was hypothesized that the ample swelling time allowed by the premixed two-solution cement would enable thorough dispersion of the additives in the solutions, resulting in no detrimental effects after polymerization. The addition of Hydroxyapatite and Brushite both caused an increase in cement viscosity; however, these cements exhibited high shear-thinning, which facilitated injection. In gel point studies, the composite cements showed no detectable change in gel point time compared to an all-acrylic control cement. Hydroxyapatite and Brushite composite cements were observed to have high mechanical strengths even at high loads of calcium phosphate fillers. These cements showed an average compressive strength of 85 MPa and flexural strength of 65 MPa. A calcium phosphate-containing cement exhibiting a combination of high viscosity, pseudoplasticity and high mechanical strength can provide the essential bioactivity factor for osseointegration without sacrificing load-bearing capability.

APA, Harvard, Vancouver, ISO, and other styles

7

Szczesio-Wlodarczyk, Agata, Karolina Rams, Karolina Kopacz, Jerzy Sokolowski, and Kinga Bociong. "The Influence of Aging in Solvents on Dental Cements Hardness and Diametral Tensile Strength." Materials 12, no. 15 (August 2, 2019): 2464. http://dx.doi.org/10.3390/ma12152464.

Full text

Abstract:

Prosthetic materials must exhibit adequate resistance to the oral environment. The aim of this paper was to study the resistance of selected cements used for cementing restorations (Breeze—composite, Adhesor Carbofine—zinc-polycarboxylate and IHDENT–Giz type II—glass-ionomer) against ethanol, soda and green tea solutions. The highest values of hardness and DTS (diametral tensile strength) were obtained by composite cement (HV = 15–31, DTS = 34–45 MPa). Ethanol solution had the greatest impact on the hardness value of composite cement, and soda solution on zinc-polycarboxylate cement. No significant differences were noted in the DTS values of composite cements after immersion in solvents; however, the DTS value of zinc-polycarboxylate cement increased after prolonged immersion time in ethanol and the DTS of glass-ionomer cement (IHDENT Giz type II) clearly decreased after submersion in soda solutions. Variation in pH across the range of 6 (tea) to 9 (soda solution) had a low impact on the properties of dental cements. Extended exposure to solvents appears to worsen the properties of cements.

APA, Harvard, Vancouver, ISO, and other styles

8

Kumar, Rajneesh, Nisha Garg, Poonam Bogra, Vineeta Nikhil, Amit Garg, and Anamika Thakur. "The Effect of Different Post Materials and Cements on Fracture Resistance of Endodontically Treated Teeth–An in Vitro Study." Dental Journal of Advance Studies 04, no. 01 (April 2016): 038–43. http://dx.doi.org/10.1055/s-0038-1672043.

Full text

Abstract:

Abstract Objective: To evaluate the effect of various post materials and cements on fracture resistance of endodontically treated teeth. Material and methods: Three post systems; custom made Ni-Cr post and core, prefabricated stainless steel and carbon fibre post with composite core and two different luting cements i.e glass ionomer and resin cements were used. Results and conclusions: Carbon fibre post cemented with resin cements showed higher failure load than Ni-Cr and stainless steel post and resin cement performed better than glass ionomer cement, the mode of fracture was more favourable with carbon fibre post than in metallic post.

APA, Harvard, Vancouver, ISO, and other styles

9

Lassila, Lippo, Anna-Maria Le Bell-Rönnlöf, Milla Lahdenperä, and Pekka Vallittu. "Bond Strength of Composite Resin Luting Cements to Fiber-reinforced Composite Root Canal Post." Journal of Contemporary Dental Practice 8, no. 6 (2007): 17–24. http://dx.doi.org/10.5005/jcdp-8-6-17.

Full text

Abstract:

Abstract Aims The aim of this study was to compare the attachment of different composite resin luting cements to a fiber-reinforced composite (FRC) post with a semi-interpenetrating polymer network polymer matrix. Methods and Materials Six different brands of composite resin luting cement stubs were applied on the surface of FRC post material and light-cured for 40 seconds. Shear bond strengths of luting cement stubs were measured using a universal testing machine. Results The differences in shear bond strengths between the cements were not statistically significant. Conclusion All of the tested composite resin luting cements provided acceptable attachment to the tested FRC post. The tested FRC post material is suitable to use with different composite resin luting cements. Citation Le Bell-Rönnlöf AM, Lahdenperä M, Lassila L, Vallittu P. Bond Strength of Composite Resin Luting Cements to Fiber-reinforced Composite Root Canal Post. J Contemp Dent Pract 2007 September; (8)6:017-024.

APA, Harvard, Vancouver, ISO, and other styles

10

Liu, Xing, Can Cheng, Xu Peng, Hong Xiao, Chengrui Guo, Xu Wang, Li Li, and Xixun Yu. "A promising material for bone repair: PMMA bone cement modified by dopamine-coated strontium-doped calcium polyphosphate particles." Royal Society Open Science 6, no. 10 (October 2019): 191028. http://dx.doi.org/10.1098/rsos.191028.

Full text

Abstract:

Polymethyl methacrylate (PMMA) bone cement has been widely used in clinics as bone repair materials for its excellent mechanical properties and good injection properties. However, it also has defects such as poor biological performance, high temperature, and the monomer has certain toxicity. Our study tried to modify the PMMA bone cement by doping with various particle weight fractions (5, 10 and 15%) of SCPP particles and polydopamine-coated SCPP particles (D/SCPP) to overcome its clinical application disadvantages. Our study showed that all results of physical properties of samples are in accordance with ISO 5833. The 15% D/SCPP/PMMA composite bone cement had much better biocompatibility compared with pure PMMA bone cement and SCPP/PMMA composite bone cement due to the best cell growth-promoting mineralization deposition on the surface of 15% D/SCPP/PMMA composite bone cements and Sr 2+ released from SCPP particles. Our research also revealed that the reaction temperature was found to be reduced with an increase in doped particles after incorporating the particles into composite bone cements. The novel PMMA bone cements modified by D/SCPP particles are promising materials for bone repair.

APA, Harvard, Vancouver, ISO, and other styles

11

Iskandarova, Mastura, Gulruh Begjanova, Dilshod Mukhitdinov, Zukhra Yakubzhanova, and Burxon Botirov. "Technological foundations for solving problem of metallurgy and TPP waste utilization for development of "Green" technology for composite cements production." E3S Web of Conferences 365 (2023): 01001. http://dx.doi.org/10.1051/e3sconf/202336501001.

Full text

Abstract:

The chemical-mineralogical compositions and physic-chemical properties of slag waste from the Angren TPP and Uzmetkombinat JSC were determined. A Conclusion was issued on their suitability for use as additives in cement and the possibility of using them for producing new types of hybrid additives for the production of composite Portland cements. With different combinations and ratios of Portland cement clinker, natural gypsum stone, and hybrid additives, the compositions of composite Portland cements were obtained and optimized, and Conclusions were issued on their compliance with the requirements of the Standard of the Republic of Uzbekistan Uz DSt 2830:2014 "Portland cement with composite additives. Specifications".

APA, Harvard, Vancouver, ISO, and other styles

12

Duraisamy, Vijayakumar, Gopinath Athira, Abdulsalam Bahurudeen, and Prakash Nanthagopalan. "Composite cements: synergistic effects of particle packing and pozzolanicity." Proceedings of the Institution of Civil Engineers - Engineering Sustainability 175, no. 1 (February 1, 2022): 12–21. http://dx.doi.org/10.1680/jensu.21.00076.

Full text

Abstract:

The production of cement is a carbon dioxide-intensive process. Replacing ordinary Portland cement (OPC) with industrial by-products can bring down the carbon footprint associated with cement production. Various industrial residues are currently used as alternative cementitious materials in this regard. However, developing a low carbon dioxide composite cement with different pozzolans alters the packing density, which influences its properties. Although studies have been conducted on the use of fly ash and slag at lower cement replacement levels, studies on the packing density and strength of ternary and quaternary composite cements with higher replacement levels are limited. In this study, fly ash, blast-furnace slag, ultra-fine fly ash and ultra-fine slag are used as a partial replacement for cement in various proportions. Out of the 51 mixtures tested in the study, 11 combinations were selected, based on the maximum packing density, for further investigations on fresh and hardened properties to arrive at the best trade-off between cement reduction and desired properties. The early-age strength is influenced by the packing density of composite cements, whereas the later-age strength is found to be highly governed by the amount of OPC and the pozzolanic potential of the industrial by-products.

APA, Harvard, Vancouver, ISO, and other styles

13

Liu, Hong Yan, Ping Zhao, Chen Feng, and Rohit Sharma. "Cement-Sand Based Piezoelectric Smart Composites." Applied Mechanics and Materials 392 (September 2013): 9–13. http://dx.doi.org/10.4028/www.scientific.net/amm.392.9.

Full text

Abstract:

In this paper, preliminary investigation of a new cement-sand based piezoelectric composite was conducted for potential structural engineering applications. PZT ceramic powder has been incorporated into cement material to form composite smart materials in earlier studies and showed promising outcome. However, the previous studies were limited to using only PZT and cement. In this study, PZT powder mixed with cement and sand, which is more realistic in civil engineering applications. The compressive strength of the composites with different PZT volume ratios was investigated. The results showed that embed PZTs increased the strength of the composites. Modified Sawyer-Tower circuit was applied to pole the composites in order to obtain the desired electrical properties of the composites. The mechanical and electrical properties of this type of new smart material had been investigated experimentally. Through a series of MTS compression tests, feasibility of using cement-sand based PZT composite materials in civil engineering is evaluated.

APA, Harvard, Vancouver, ISO, and other styles

14

Askar Zhambulovich, Aimenov, Khudyakova Tatyana Mikhailovna, Sarsenbayev Bakytzhan Kudaibergenovich, Dzhakipbekova Nagima Ormanovna, Ali Khalid Abdul Khalim Kheidar, and Alvein Yaser Mukhamed Ali. "Studying the Mineral Additives Effect on a Composition and Properties of a Composite Binding Agent." Oriental Journal of Chemistry 34, no. 4 (August 20, 2018): 1945–55. http://dx.doi.org/10.13005/ojc/3404031.

Full text

Abstract:

A Portland cement is a basic initial component for concrete and reinforced concrete manufacture, which defines their technical-economic and operational properties. One of a perspective ways of increase in the efficiency of cement production without essential change of its technology is inclusion of various mineral additives influencing on a structure and properties of a cement stone. As power inputs make the most part of the costs necessary for cement manufacture, the cement industry is interested in decrease in fuel and electric power expenditures per 1 tonne of cement. To reach the decrease in power inputs and at the same time to raise the environmental safety of cement production the cement industry is recently focused on increase in output of composite cements. Composite cements not only promote optimization of the production in terms of ecology, but also can provide such technical advantages as lower hydration heat, higher chemical resistance and placeability.

APA, Harvard, Vancouver, ISO, and other styles

15

Ponco, Vinansius, Jonie Tanijaya, and Olan Jujun Sanggaria. "Comparison Of Concrete Using Portland Composite Cement And Ordinary Portland Cement." Paulus Civil Engineering Journal 3, no. 3 (October 10, 2021): 406–11. http://dx.doi.org/10.52722/pcej.v3i3.292.

Full text

Abstract:

Cement is the basic material for making concrete that can be used as a hydraulic binder. There are various types of cement including OPC and PCC cement. The problem now is that there is no technical data that can be used as a reference in determining the proportion of the mixture. Examples of cement are obtained from the same factory. namely PT. Semen Tonasa, South Sulawesi with an amount of 78.96 kg of cement for each type of cement. From the results of laboratory tests, it was found that the data on the comparison of concrete using OPC and PCC cements had different data on the of OPC cement is 3.726 Mpa and PCC cement is 3.223 Mpa and for testing the modulus of elasticity of OPC cement is 19371.316 Mpa and PCC cement is 17579.182 Mpa. The test results have met the standard for structural concrete with the same water-cement factor.

APA, Harvard, Vancouver, ISO, and other styles

16

Kazragis, Algimantas, Aušra Juknevičiūte, and Albinas Gailius. "UTILIZATION OF BOON AND CHAFF FOR MANUFACTURING LIGHTWEIGHT WALLING MATERIALS." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 12, no. 1 (March 31, 2004): 12–21. http://dx.doi.org/10.3846/16486897.2004.9636810.

Full text

Abstract:

Lightweight composites for walls and thermal insulation, containing anhydrite (An) or aluminate cement (Al), vinyl acetate (VA) or cellulose (Cl) polymeric binders and cellulose fiber fillers (boon, chaff) were produced. The best results were obtained for transportation and construction of items containing: An ≥ 30–45 %, Al ≥ 30–50 %, VA ≥ 1–5 %, Cl ≥ 0,5–5,0 %, boon or chaff ≥ 40–47 %. Polymeric binder VA for both kinds of cement is better than Cl. An is better for boon than for chaff. Aluminate cement is a good binder for both types of fiber fillers. Density r of a composite containing cements 50–60 % is less than 400 kg/m3. According to density such composite materials are light‐weight heat‐insulating materials. Density (p ≤ kg/m3) depends on the amount of cement content. Bending strength for samples with p ≤ 400 kg/m3, containing CMC is 0,6–1,3 MPa. Coefficient of thermal conductivity for samples, density with 400 kg/m3 is 0,06 W/m‐K.

APA, Harvard, Vancouver, ISO, and other styles

17

Rattanachan, Sirirat, Piyanan Boonphayak, and Charussri Lorprayoon. "Original article. Development of chitosan/nanosized apatite composites for bone cements." Asian Biomedicine 5, no. 4 (August 1, 2011): 499–506. http://dx.doi.org/10.5372/1905-7415.0504.065.

Full text

Abstract:

Abstract Background: Calcium phosphate cements (CPC) is a promising materials for bone defect repair. Nanosized apatite or calcium orthophosphate has a better bioactivity than coarser crystals. Chitosan is produced commercially from chitin that is the structural element in the exoskeleton of crustaceans such as crabs and shrimp. The mixing of nanosized apatite and chitosan may provide the consistency cement, improving mechanical properties of the set bone cement. Objective: Develop nanosized apatite powder with chitosan for bone composite cement. Materials and method: Nanosized apatite was synthesized by chemical method at low temperature and used as the single-component for bone cement. The nanosized apatite powder was characterized using X-ray diffraction method, Fourier transform infrared spectroscopy, and transmission electron microscopy. CPCs were developed based on chitosan/nanosized apatite and calcium sulfate hemihydrate. The compressive strength of the set cement was measured after one to four weeks. The phase composition and the morphology of the set cements were investigated. Results: Calcium sulfate hemihydrate was effective in increasing the compressive strength after setting in a simulated body fluid for seven days. The compressive strength of chitosan/nanosized apatite composite was about 18 MPa after soaking. Conclusion: The workability and setting time of this composite were suitable to handling for bone cement. These composite cements had a significant clinical advantage for substitution of the regenerated bone.

APA, Harvard, Vancouver, ISO, and other styles

18

Rohr, N., N. Bertschinger, J. Fischer, A. Filippi, and NU Zitzmann. "Influence of Material and Surface Roughness of Resin Composite Cements on Fibroblast Behavior." Operative Dentistry 45, no. 5 (March 27, 2020): 528–36. http://dx.doi.org/10.2341/19-113-l.

Full text

Abstract:

Clinical Relevance A well-polished cement surface increases the viability and spreading of gingival fibroblasts. The tested resin composite cements did not reveal any cytotoxic effects. SUMMARY Objective: This in vitro study aimed to investigate the effect of cement type and roughness on the viability and cell morphology of human gingival fibroblasts (HGF-1). Methods and Materials: Discs of three adhesive (Panavia V5 [PV5], Multilink Automix [MLA], RelyX Ultimate [RUL] and three self-adhesive (Panavia SA plus [PSA], SpeedCem plus [SCP], RelyX Unicem [RUN]) resin composite cements were prepared with three different roughnesses using silica paper grit P180, P400, or P2500. The cement specimens were characterized by surface roughness and energy-dispersive X-ray spectroscopic mapping. A viability assay was performed after 24 hours of incubation of HGF-1 cells on cement specimens. Cell morphology was examined with scanning electron microscopy. Results: The roughness of the specimens did not differ significantly among the different resin composite cements. Mean Ra values for the three surface treatments were 1.62 ± 0.34 μm for P180, 0.79 ± 0.20 μm for P400, and 0.17 ± 0.08 μm for P2500. HGF-1 viability was significantly influenced by the cement material and the specimens’ roughness, with the highest viability for PSA ≥ RUN = MLA ≥ SCP = PV5 > RUL (p<0.05) and for P2500 = P400 > P180 (p<0.001). Cell morphology did not vary among the materials but was affected by the surface roughness. Conclusion: The composition of resin composite cements significantly affects the cell viability of HGF-1. Smooth resin composite cement surfaces with an Ra of 0.2–0.8 μm accelerate flat cell spreading and formation of filopodia.

APA, Harvard, Vancouver, ISO, and other styles

19

Mao, Ke Zheng, Ke Ya Mao, Zi Shen Cheng, Peng Li, Zong Gang Chen, Xu Mei Wang, and Fu Zai Cui. "Performance of Composite Cements in the Repair of Porcine Thoracolumbar Burst Fracture In Vitro." Materials Science Forum 745-746 (February 2013): 13–20. http://dx.doi.org/10.4028/www.scientific.net/msf.745-746.13.

Full text

Abstract:

An ideal injectable bone cement should be able to fill fully the fractures gap and provide good mechanical support. In the present work, the mineralized collagen and calcium sulphate dehydrate (CSD) was incorporated into α-calcium sulphate hemihydrates (α-CSH) to explore an injectable composite cement. The injectability, the setting time and the biomechanics properties were investigated. A porcine thoracolumbar burst fracture model was used to evaluate the biomechanical performance of composite cements. The porcine thoracolumbar burst fracture models in vitro were prepared. A half of models was made by the vertebroplasty of the composite cements, the other half of models was used as control. Imaging analysis showed the composite cements distributed uniformly and solidified well. Biomechanical test showed the ability of the composite cements to repair spinal burst fractures was significant.

APA, Harvard, Vancouver, ISO, and other styles

20

PELISSER, F., B. V. SILVA, M. H. MENGER, B. J. FRASSON, T. A. KELLER, A. J. TORII, and R. H. LOPEZ. "Structural analysis of composite metakaolin-based geopolymer concrete." Revista IBRACON de Estruturas e Materiais 11, no. 3 (May 2018): 535–43. http://dx.doi.org/10.1590/s1983-41952018000300006.

Full text

Abstract:

Abstract The study of alternative binders to Portland cement, such as geopolymer cements, offers the chance to develop materials with different properties. With this purpose, this study evaluated experimentally the mechanical behavior of a geopolymer concrete beam and compared to a Finite Element (FE) nonlinear numerical model. Two concrete beams were fabricated, one of Portland cement and another of metakaolin-based geopolymer cement. The beams were instrumented with linear variable differential transformers and strain gauges to measure the deformation of the concrete and steel. Values for the compressive strength of the geopolymer cement concrete was 8% higher than the Portland cement concrete (55 MPa and 51 MPa, respectively) and the tensile rupture strength was also 8% higher (131 kN) for the geopolymer concrete beam in relation to Portland cement concrete beam (121 kN). Distinct failure mechanisms were verified between the two samples, with an extended plastic deformation of the geopolymer concrete, revealing post-fracture toughness. The geopolymer concrete showed higher tensile strength and better adhesion in cement-steel interface.

APA, Harvard, Vancouver, ISO, and other styles

21

Piemjai, Morakot, and Nobuo Nakabayashi. "Direct Tensile Strength and Characteristics of Dentin Restored with All-Ceramic, Resin-Composite, and Cast Metal Prostheses Cemented with Resin Adhesives." BioMed Research International 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/656948.

Full text

Abstract:

A dentin-cement-prosthesis complex restored with either all-porcelain, cured resin-composite, or cast base metal alloy and cemented with either of the different resin cements was trimmed into a mini-dumbbell shape for tensile testing. The fractured surfaces and characterization of the dentin-cement interface of bonded specimens were investigated using a Scanning Electron Microscope. A significantly higher tensile strength of all-porcelain (12.5 ± 2.2 MPa) than that of cast metal (9.2 ± 3.5 MPa) restorations was revealed with cohesive failure in the cement and failure at the prosthesis-cement interface in Super-Bond C&B group. No significant difference in tensile strength was found among the types of restorations using the other three cements with adhesive failure on the dentin side and cohesive failure in the cured resin. SEM micrographs demonstrated the consistent hybridized dentin in Super-Bond C&B specimens that could resist degradation when immersed in hydrochloric acid followed by NaOCl solutions whereas a detached and degraded interfacial layer was found for the other cements. The results suggest that when complete hybridization of resin into dentin occurs tensile strength at the dentin-cement is higher than at the cement-prosthesis interfaces. The impermeable hybridized dentin can protect the underlying dentin and pulp from acid demineralization, even if detachment of the prosthesis has occurred.

APA, Harvard, Vancouver, ISO, and other styles

22

Panfilova, Marina, Nikolay Zubrev, Olga Novoselova, and Sania Efremova. "Composite grouting mortar based on 3D-NKM - nanocrystalline inoculant." MATEC Web of Conferences 196 (2018): 04061. http://dx.doi.org/10.1051/matecconf/201819604061.

Full text

Abstract:

For the waterproofing of tunnels and the uniform distribution of space between the lining of tunnels and rock, composite injection solutions are used. To improve the physical and mechanical properties of cement composites, the nanoconstruction effect is used, which is possible when using nanoparticles with extended geometry. Nano-additives and nanomodifiers consisting of nanoparticles, both natural and artificial and technogenic, can be used for the production of cement-containing solutions and concretes. For example, under certain conditions nanocrystalline powder of oxides and hydroxides of aluminum to nanotechnogenic raw materials can be referred to wastes of technogenic origin. The paper investigated the effect of nano-additives-boehmite, which is a waste of production, to increase the strength and frost resistance of plugging materials made on the basis of cement when administered. It is established that the use of boehmite as an additive in cements leads to an increase in the strength properties of concrete and increase its frost resistance, which is a prerequisite for long-term and reliable operation of the composite solution. Thus, the composite solution modified by boehmite is the basis for the creation of plugging solutions

APA, Harvard, Vancouver, ISO, and other styles

23

Jašek, Marek, Jiri Brozovsky, Lucie Mynarzová, and Jan Hurta. "Development of Green Engineered Cementitious Composites." Advanced Materials Research 1020 (October 2014): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amr.1020.3.

Full text

Abstract:

A development of fiber-cement composites is often focused on cost-effective and environmentally friendly materials (so-called green materials). Production of this material should produce less waste and it also should use less energy and less natural sources. There are numerous approaches to the development of green composites. One of the possible ways is a utilization of fly ashes instead of the cement part of composite. The paper discusses a development of green cementitious composite which incorporated fly ash materials produced in the Moravian-Silesian region as a partial replacement of the cement part of the composite.

APA, Harvard, Vancouver, ISO, and other styles

24

Hasan, K. M. Faridul, Péter György Horváth, and Tibor Alpár. "Development of lignocellulosic fiber reinforced cement composite panels using semi-dry technology." Cellulose 28, no. 6 (February 22, 2021): 3631–45. http://dx.doi.org/10.1007/s10570-021-03755-4.

Full text

Abstract:

AbstractThere is a growing interest in developing cement bonded lignocellulosic fiber (LF) composites with enhanced mechanical performances. This study assessed the possibility of developing composite panels with 12 mm thickness and around 1200 kg/m3 nominal densities from ordinary Portland cements (OPC) and mixed LFs from seven different woody plants found in Hungary. Once the mixed LFs were sieved and found fine (0–0.6 mm) and medium (0.6–0.8 mm) length fibers. The optimum ratio for LF, OPC, water glass (Na2SiO3), and cement stone was found to be 1:3.5:0.7:0.07. The semi-dry process, which is a comparatively cheaper and less labor intensive technology, was used for producing the composites. After 28 days of curing, the composite panels were characterized for mechanical, physical, thermal, and morphological properties. A scanning electron microscopy (SEM) test was conducted to observe the fiber orientation in the matrix before and after the bending test, which showed the clear presence of the fibers in the composites. The FTIR (Fourier transform infrared spectroscopy) was conducted to investigate the presence of chemical compounds of LF in the composite panels. Different physical (water absorption and thickness swelling) characteristics of the composite panels were investigated. Furthermore, mechanical properties (flexural properties and internal bonding strength) of the composite panels were also found to be satisfactory. The flexural modulus and internal bonding strengths of composite panel 2 is higher than other three boards, although the flexural strength is a little lower than composite panel 1. The thermogravimetric analysis and differential thermogravimetry also indicated better thermal stability of composite panels which could be used as potential insulation panel for buildings. Graphic abstract

APA, Harvard, Vancouver, ISO, and other styles

25

Tian, Kun, Sheng Yin Zhou, Jiang Rong Xiao, Ru Guang Li, and Peng Yao. "Design and Preparation of Cement-Based Composite with Electromagnetic Protection." Materials Science Forum 743-744 (January 2013): 382–88. http://dx.doi.org/10.4028/www.scientific.net/msf.743-744.382.

Full text

Abstract:

Using space electromagnetic wave propagation principle, environment requirements of building protective engineering structure and performance characteristics of cement-based composites, a design idea of cement-based composite with electromagnetic protection is presented in the present study. This design idea was tested and verified. According to the proposed new designed method, by optimizing and selecting the wave-transparent aggregate and absorbing agent material, the absorbing composite materials of cement-based electromagnetic protection, electromagnetic wave absorbent, energy saving and environmental protection can be improved. A new cement-based composite with electromagnetic protection and microwave absorbing properties (the minimum reflectivity is-8.4dB), wide frequency bandwidth, and letter mechanical properties was prepared by using a 20 mm sample between 8-18 GHz. The results provide a basis design and preparation of cement-based composite with electromagnetic protection.

APA, Harvard, Vancouver, ISO, and other styles

26

Nasrudin, Malun, Dwi Warna Aju Fatmawati, and FX Ady Soesetijo. "PERBANDINGAN UJI KEBOCORAN TEPI RESIN KOMPOSIT FLOWABLE DAN BAHAN LUTING SEMEN PADA PASAK POLYETHYLENE FIBER-REINFORCED (PFR)." ODONTO : Dental Journal 3, no. 1 (July 1, 2016): 27. http://dx.doi.org/10.30659/odj.3.1.27-33.

Full text

Abstract:

Background: Zinc phosphate, glass-ionomer, and resin cement are the most commonly used as luting cements. Flowable composite resin could reduce restoration microleakage and provided better marginal seal in dentin. Purpose: The objective of the study was to compare microleakage between flowable composite resin and cement luting materials.Methods: The study was experimental laboratory by the post test only without control group design. The sample size was 18, which was divided into 3 groups. Each group consisted of 6 samples. Glass-ionomer cement and zinc phosphate were luting cement materials that used in the study. Microleakage measurement method used stereomicroscope after the samples were stored in methylen blue 0.25%.Results: The smallest average value of microleakage was in the flowable composite resin group (29,16%). One way ANOVA test results showed that there were significant differences between treatment groups (p=0.000). Conclusion: It was concluded that flowable composite resin have smaller microleakage average value than glass-ionomer cement and zinc phosphate.

APA, Harvard, Vancouver, ISO, and other styles

27

Wu, Karl, Yu-Chun Chen, Shang M. Lin, and Chih-Hung Chang. "In vitro and in vivo effectiveness of a novel injectable calcitonin-loaded collagen/ceramic bone substitute." Journal of Biomaterials Applications 35, no. 10 (January 31, 2021): 1355–65. http://dx.doi.org/10.1177/0885328221989984.

Full text

Abstract:

This study aimed to evaluate the effectiveness of a novel calcitonin-loaded calcium phosphate composite bone cement in vitro and in vivo. The novel composite bone cements were composed of NuROs injectable bone graft substitute, type I collagen, and/or salmon calcitonin. The setting time, porosity, wettability, compressive strength, compressive modulus, and crystallographic structures of cement specimens were determined. Degradation rate, calcitonin release rate, and osteoinductivity were assessed in vitro. In addition, osteogenic effect was examined in a rabbit model of femoral defect. The results revealed that addition of collagen/calcitonin did not substantially alter physical properties and degradation rate of bone cement specimens. Calcitonin was released into culture medium in a two-phase manner. Osteogenic effect of conditioned medium derived from calcitonin containing bone cement was observed. Finally, de novo bone growth and bone mineralization across the bone defect area were observed in rabbits after implantation of composite bone cement specimens. In conclusion, this novel calcitonin-loaded composite calcium phosphate bone cement exhibits biocompatibility, bioresorbability, osteoinductivity, and osteoconductivity, which may be suitable for clinical use.

APA, Harvard, Vancouver, ISO, and other styles

28

Łukowski, P., and G. Adamczewski. "Self-repairing of polymer-cement concrete." Bulletin of the Polish Academy of Sciences: Technical Sciences 61, no. 1 (March 1, 2013): 195–200. http://dx.doi.org/10.2478/bpasts-2013-0018.

Full text

Abstract:

Abstract Self-repairing means ability to the total or partial recovering of the properties which were worsened as a consequence of damage of the material. The subject of the paper is evaluation of ability to self-repair of a cement composite modified with epoxy resin without a hardener. The methodology of investigation of self-repairing building materials, developed by the authors, has been described, with controllable enforcing of the limited weakening of the material. Also, the self-repair degree has been defined as the measure of self-repairing ability of the building composites. The material model of the epoxy-cement composite has been developed on the basis of the tests results. The material optimization of the composite towards the maximum self-repairing ability has also been carried out. The results of investigation have confirmed the possibility of self-repairing of the cement composite modified with the epoxy resin without hardener. The conclusion and further research needs in the range of the self-repairing epoxy-cement composites have been pointed out

APA, Harvard, Vancouver, ISO, and other styles

29

Wang, Wei Guo, Gang Ling Hao, Xin Cheng Ren, and Lei Lv. "Damping Properties of Li₆La₂SrBi₂O₁₂ Ceramic Particulates Reinforced Cement Composites." Advanced Materials Research 512-515 (May 2012): 1873–76. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.1873.

Full text

Abstract:

The higher damping capacity and hardness Li6La2SrBi2O12ceramic particles at room temperature were added into the cement to form the composite materials. The maximum damping capacity of the 25 wt% Li6La2SrBi2O12ceramic/cement composites is as high as 0.015 at 310 K and 9 Hz, corresponding to a vibration energy dissipation of about 10% in each vibration cycle. The flexural strength of the the 10 wt% Li6La2SrBi2O12ceramic/cement composite is about 50% higher than that of the pure cement sample

APA, Harvard, Vancouver, ISO, and other styles

30

Chaipanich, Arnon, and Nittaya Jaitanong. "Fabrication and Properties of PZT-Cement-Encapsulated Carbon Composites." Key Engineering Materials 421-422 (December 2009): 428–31. http://dx.doi.org/10.4028/www.scientific.net/kem.421-422.428.

Full text

Abstract:

Lead zirconate titanate, Pb(Zr0.52Ti0.48)O3 (PZT) has excellent piezoelectric properties and has been used in a number of applications such as sensors and actuators. Recently, PZT has been used with a cement based material to produce new types of composite. These new piezoelectric-cement based composites have been developed for sensor applications in civil engineering works where these composites would provide better matching to concrete than the existing normal piezoelectric ceramic or piezoelectric-polymer composites. In this work, encapsulated carbon addition of 2% by volume was added to the PZT-cement composites using pressed-cured method. Dielectric properties of the composites were investigated from 1 to 100 kHz as a preliminary investigation. The results show that the dielectric constant was found to be higher for the composite with the addition of encapsulated carbon. The dielectric loss of the composite with the encapsulated carbon, however, was found to be less when compared to the composite with no encapsulated carbon. Scanning electron micrographs of these composites also revealed that a dense microstructure can be obtained from this method.

APA, Harvard, Vancouver, ISO, and other styles

31

Khezhev, Tolya, Tamerlan Badziev, Talib Soblirov, and Timur Tamashev. "Gypsum-Cement Composites Based on Volcanic Ash." Materials Science Forum 1011 (September 2020): 136–43. http://dx.doi.org/10.4028/www.scientific.net/msf.1011.136.

Full text

Abstract:

The studies’ results to determine the gypsum, ash and Portland cement components proportions, which would ensure a decrease in the specific binder consumption, as well as the ash grain composition’s effect on the properties of the gypsum cement pozzolan composite, are presented. It was revealed that the use of volcanic ash together with Portland cement in gypsum concrete composites allows reducing gypsum consumption by up to 50% without a significant decrease in strength characteristics. At the same time, the developed gypsum concrete composites have increased water resistance. The influence of the ash particle size distribution on the strength properties of the composite is ambiguous; in the compositions with a high ash content it is advisable to use larger fractions, and with a content of less than 50% ash in the composite, - the small fractions. To study the parameters’ effect of the dispersed reinforcement with basalt fibers on the properties of a gypsum-cement composite, an experiment with such a second-order composite rotatable plan as regular hexagon was conducted. It was found that the maximum values of optimization parameters are observed in the central area of the plan with and . The compressive strength of a fiber gypsum cement pozzolan composite increases by 1.15-1.18 times, when bending, by 1.56-1.72 times with respect to the strength of the initial matrix.

APA, Harvard, Vancouver, ISO, and other styles

32

Li, Wei-Wen, Wei-Ming Ji, Yi Liu, Feng Xing, and Yu-Kai Liu. "Damping Property of a Cement-Based Material Containing Carbon Nanotube." Journal of Nanomaterials 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/371404.

Full text

Abstract:

This study aimed to explore the damping property of a cement-based material with carbon nanotube (CNT). In the study, the cement composites with different contents of CNT (0 wt%, 0.033 wt%, 0.066 wt%, and 0.1 wt%) were investigated. Logarithmic Decrement method and Dynamic Mechanical Analysis (DMA) method were utilized to study the damping property of CNT/cement composite. The influences of CNT on pore size distribution and microstructure of composite were analyzed by Mercury Intrusion Porosimetry (MIP) and Scanning Electron Microscopy (SEM), respectively. The experimental results showed that CNT/cement composite presented higher flexural strength index than that of a pure cement paste. Additional CNT could improve the vibration-reduction capacity of cement paste. Furthermore, the experiments proved that CNT could bridge adjacent hydration products and support load transfer within cement matrix, which contributed to the energy dissipation during the loading process.

APA, Harvard, Vancouver, ISO, and other styles

33

Krivenko, Pavel V., Myroslav Sanytsky, and Tetiana Kropyvnytska. "The Effect of Nanosilica on the Early Strength of Alkali-Activated Portland Composite Cements." Solid State Phenomena 296 (August 2019): 21–26. http://dx.doi.org/10.4028/www.scientific.net/ssp.296.21.

Full text

Abstract:

Significant reduction of carbon footprint of the construction industry is achieved through the use of composite Portland cements. However, substitution levels of additives in the composite cements are limited due to slow strength development arising from low reactivity of the pozzolana compared to clinker phases especially at the early age. The aim of the study was to evaluate effect of nanosilica on formation of strength properties and structure at the early age. The Portland composite cement containing clinker, granulated blast furnace slag, zeolite tuff as natural pozzolana and limestone with additives of nanosilica, Na2SO4 and polycarboxylate ether was investigated. The results obtained with the help of PSD, XRD, DTA, TG and SEM techniques showed that addition into the cement paste of the nanosilica particles with high surface reactivity improved the composite cement microstructure and leaching of calcium became significantly lower, because nanosilica particles react with calcium hydroxide with the formation of a denser C-S-H gel at the early age of hardening.

APA, Harvard, Vancouver, ISO, and other styles

34

Medvecky, Lubomir, Radoslava Stulajterova, Maria Giretova, Tibor Sopcak, Maria Faberova, Miroslav Hnatko, and Tatana Fenclova. "Calcium Phosphate Cement Modified with Silicon Nitride/Tricalcium Phosphate Microgranules." Powder Metallurgy Progress 20, no. 1 (June 1, 2020): 56–75. http://dx.doi.org/10.2478/pmp-2020-0006.

Full text

Abstract:

Abstract Tetracalcium phosphate/monetite biocement was modified with 10 and 30 wt. % addition of highly porous silicon nitride/α-tricalcium phosphate (αTCP) microgranules with various content of αTCP. A composite cement powder mixture was prepared using mechanical homogenization of basic components. The accelerated release of dexamethasone from composite cement was revealed, which indicates their possible utilization for controlled drug release. The wet compressive strength of cements (<17 MPa) was significantly reduced (more than 30%) in comparison with the unmodified cement and both compressive strength and setting time were influenced by the content of αTCP in microgranules. The addition of microgranules caused a 20% decrease in final cement density. Microgranules with a higher fraction of αTCP showed good in vitro SBF bioactivity with precipitation of hydroxyapatite particles. Microstructure analysis of fractured cements demonstrated excellent interconnection between microgranules and cement calcium phosphate matrix, but also showed lower mechanical strength of microgranule cores.

APA, Harvard, Vancouver, ISO, and other styles

35

Thomas, Mathew, Mohammed Mustafa, Reshma Karkera, AP Nirmal Raj, Lijo Isaac, and R. Naveen Reddy. "Comparison of the Solubility of Conventional Luting Cements with that of the Polyacid Modified Composite Luting Cement and Resin-modified Glass Ionomer Cement." Journal of Contemporary Dental Practice 17, no. 12 (2016): 1016–21. http://dx.doi.org/10.5005/jp-journals-10024-1974.

Full text

Abstract:

ABSTRACT Introduction This study was planned to find the solubility of the conventional luting cements in comparison with that of the polyacid-modified composite luting cement and recently introduced resin-modified glass ionomer cement (RMGIC) with exposure to water at early stages of mixing. Materials and methods An in vitro study of the solubility of the following five commercially available luting cements, viz., glass ionomer cement (GIC) (Fuji I, GC), zinc phosphate (Elite 100, GC), polyacid-modified resin cement (PMCR) (Principle, Dentsply), polycarboxylate cement (PC) (Poly - F, Dentsply), RMGIC (Vitremer, 3M), was conducted. For each of these groups of cements, three resin holders were prepared containing two circular cavities of 5 mm diameter and 2 mm depth. All the cements to be studied were mixed in 30 seconds and then placed in the prepared cavities in the resin cement holder for 30 seconds. Results From all of the observed luting cements, PMCR cement had shown the lowest mean loss of substance at all immersion times and RMGIC showed the highest mean loss of substance at all immersion times in water from 2 to 8 minutes. The solubility of cements decreased by 38% for GIC, 33% for ZnPO4, 50% for PMCR, 29% for PC, and 17% for RMGIC. Conclusion The PMCR cement (Principle-Dentsply) had shown lowest solubility to water at the given time intervals of immersion. This was followed by PC, zinc phosphate, and GIC to various time intervals of immersion. How to cite this article Karkera R, Nirmal Raj AP, Isaac L, Mustafa M, Reddy RN, Thomas M. Comparison of the Solubility of Conventional Luting Cements with that of the Polyacid Modified Composite Luting Cement and Resin-modified Glass Ionomer Cement. J Contemp Dent Pract 2016;17(12):1016-1021.

APA, Harvard, Vancouver, ISO, and other styles

36

Książek, Mariusz. "Resistance to chemical attack of cement composites impregnated with a special polymer sulfur composite." Corrosion Reviews 34, no. 4 (September 1, 2016): 211–29. http://dx.doi.org/10.1515/corrrev-2016-0032.

Full text

Abstract:

AbstractSpecific chemical environments affect industrial objects. Portland cement composites (concrete and mortar) were impregnated with a special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot were applied as industrial waste. Portland cement composites were made of the same aggregate, cement, and water. The durability of the prepared cement composite samples was tested in 5% solution of HCl and 5% solution of H2SO4 as a function of immersion time. The changes in mechanical strength and mass of the samples were periodically measured. Cement composites impregnated with sulfur composite exhibited limited mechanical strength and mass loss, while the physico-mechanical properties of the Portland cement concrete regressed rapidly. The loss in weight of ordinary concrete impregnated with sulfur composite, kept in aqueous solutions of acids, hydroxides, salts, and in water for a year was determined using 100×100×100 mm samples. The same samples were then used in compressive strength tests. The image analysis used for surface destruction monitoring, performed by scanning microscopy for the determination of damaged surface area and the original surface area before acid resistance testing, showed similar results. Based on the image analysis results, a model for predicting the degradation of mechanical strength during durability testing was established. The fact that the calculated and experimental strength values were not vastly different proved the validity of the proposed model. A brief summary of new products related to the special sulfur composite is given as follows: impregnation, repair, overlays, and precast polymer concrete will be presented. Sulfur composite as a polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

APA, Harvard, Vancouver, ISO, and other styles

37

Bassioni, Ghada. "GLOBAL WARMING AND CONSTRUCTION ASPECTS." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 2 (August 3, 2015): 78. http://dx.doi.org/10.17770/etr2009vol2.1013.

Full text

Abstract:

The manufacture of cements with several main constituents is of particular importance with regard to reducing climatically relevant CO2 emissions in the cement industry. This ecological aspect is not the only argument in favor of Portland composite cements. They are also viable alternatives to Portland cement from the technical point of view. Substitution of ordinary Portland cement (CEM I) by Portland composite cements (CEM II) and (CEM III), which clearly possess different chemical and mineralogical compositions, results in changes of their reaction behavior with additives like superplasticizers. A common admixture to CEM I in that sense is limestone (industrial CaCO3). Its interaction with polycarboxylates is ignored and its inertness is taken for granted. This study provides a systematic approach in order to better understand the interaction of these polymeric superplasticizers with CaCO3 by adsorption and zeta potential measurements. The results give some fundamental understanding in how far the cement industry can reduce the production of cement clinker by replacing it with limestone as admixture and consequently the CO2-emission is reduced, which is of high political and environmental interest.

APA, Harvard, Vancouver, ISO, and other styles

38

Güzelküçük, Selahattin, İlhami Demir, Özer Sevim, and İlker Kalkan. "Mechanical properties and microstructure of cement multicomponent systems containing pozzolan materials under sulfate attack." Cement Wapno Beton 25, no. 2 (2020): 127–53. http://dx.doi.org/10.32047/cwb.2020.25.2.6.

Full text

Abstract:

Sulfates are a significant chemical components that may lead to failures of cement concrete composites. The present study is dedicated to analyzing the effects of sulfate on the microstructure of cement composite mortars. For this purpose, cementing composite specimens were prepared with 20% pozzolan mixture [fly ash + granulated blastfurnace slag + bottom ash] by mass of cement, together with the reference additive-free specimen of cement concrete, without any mineral admixtures. These cementing composite mortar specimens were then treated for 2, 7, 28, 90, and 360 days in tap water and 10% sodium sulfate solution. The microstructure of the additive-free mortar and composite cement mortar, partially replaced with 20% pozzolan, was then investigated using a scanning electron microscope. The results showed that increasing curing time also increases the formation of C-S-H [calcium silicate hydrate] gel in the cement mortar, when the microstructural changes in the cement are explored in detail. Ettringite formation [3CaO·Al2O3·3CaSO4·32H2O] in the specimens cured in 10% Na2SO4 was also noticed, in the present experiments.

APA, Harvard, Vancouver, ISO, and other styles

39

Medved’, Igor, Ladislav Kalvoda, Eva Vejmelková, Stanislav Vratislav, and Robert Černý. "Transport of gadolinium in a cement composite." MATEC Web of Conferences 282 (2019): 02105. http://dx.doi.org/10.1051/matecconf/201928202105.

Full text

Abstract:

Development of cement based composites suitable for radionuclide immobilization is of great interest for secure containment of nuclear waste. This requires, in particular, detailed knowledge of how radionuclides are transported in such composites. In this paper we investigate the transport of gadolinium in a dry cement composite. Experimental data are obtained in a non-destructive way by neutron imaging. Their theoretical interpretation is based on a diffusion-advection model in which sorption is included.

APA, Harvard, Vancouver, ISO, and other styles

40

Choi, Yun-Wang, Sung-Rok Oh, and Byung-Keol Choi. "A Study on the Manufacturing Properties of Crack Self-Healing Capsules Using Cement Powder for Addition to Cement Composites." Advances in Materials Science and Engineering 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/5187543.

Full text

Abstract:

We fabricated crack self-healing capsules using cement powder for mixing into cement composites and evaluated the properties of the capsule manufacturing process in this study. The manufacture of the self-healing capsules is divided into core production processing of granulating cement in powder form and a coating process for creating a wall on the surfaces of the granulated cement particles. The produced capsules contain unhardened cement and can be mixed directly with the cement composite materials because they are protected from moisture by the wall material. Therefore, the untreated cement is present in the form of a capsule within the cement composite, and hydration can be induced by moisture penetrating the crack surface in the event of cracking. In the process of granulating the cement, it is important to obtain a suitable consistency through the kneading agent and to maintain the moisture barrier performance of the wall material. We can utilize the results of this study as a basis for advanced self-healing capsule technology for cement composites.

APA, Harvard, Vancouver, ISO, and other styles

41

Fernando, Sarah, Chamila Gunasekara, Amin Shahpasandi, Kate Nguyen, Massoud Sofi, Sujeeva Setunge, Priyan Mendis, and Md Tareq Rahman. "Sustainable Cement Composite Integrating Waste Cellulose Fibre: A Comprehensive Review." Polymers 15, no. 3 (January 19, 2023): 520. http://dx.doi.org/10.3390/polym15030520.

Full text

Abstract:

This review presents the research conducted to date in the field of cement-based composites reinforced with waste paper-based cellulose fibres, focusing on their composition, mechanical properties, and durability characteristics. The literature demonstrates that the properties of raw material (depending on their own chemical composition) significantly influence the formation of the cement composite binders. When considering fresh properties, the presence of silica and magnesium compounds generally lead to favourable effects on the setting of the cement composite when combined with waste paper cellulose fibre. Reduction in density values, i.e., approximately 25%, was observed with the inclusion of waste paper fibres from 20 to 80% in cement composites. The homogeneous dispersion of fibres in the matrix is one of the crucial factors to achieve in order to develop composites with well-balanced mechanical properties incorporating waste paper cellulose fibres. Hence, dispersion of fibres can be improved by increasing water quantity corresponding to the optimal value, which was a water/cement ratio of 0.64 leading to optimum strength properties of the composite. Even though the effect of fibre dispersion in the matrix improves with the addition of water, higher porosity and voids govern the strength properties beyond an optimum water-to-cement ratio. Higher porosity leads to an increase in the water absorption and a lowering of the thermal conductivity properties with the addition of paper fibre in cement binders. Paper fibre absorbs a high amount of water leading to higher water absorption. This phenomenon is related to the hydrophilic nature of cellulosic fibres absorbing some volume of water due to their microporous structure.

APA, Harvard, Vancouver, ISO, and other styles

42

Iubin, Petr, and Lubov Zakrevskaya. "Soil-concrete for use in the 3D printers in the construction of buildings and structures." MATEC Web of Conferences 245 (2018): 03002. http://dx.doi.org/10.1051/matecconf/201824503002.

Full text

Abstract:

Nowadays, the construction of cement composite using 3D printers is considered one of the most promising methods of automation of building processes. However, the compositions of cement composites have several disadvantages, such as high cost, short workability and etc. It has been suggested that clay soil as an additive will help to solve these problems partially. The aim of the work is development the cement compositions with clay soil, for use in 3D printers to construction. The composite consists of cement paste with clay soil and additives. To study printability of a composite the rheological properties in a fresh state were studied. The study of the rheological properties of composites was carried out using a flow table test for mortar. The key factor for determining the suitability of the composite for printing was accepted the diameter of the cone after shaking. The test results showed the possibility of replacing cement paste with clay soil up to 25% which leads to a reduction in the cost and an increase in printability with a slight decrease in the strength of the obtained material to 7%. Utilizing of soil from the construction site provides maximum economic efficiency of the material application.

APA, Harvard, Vancouver, ISO, and other styles

43

Skapska, Anastazja, Zenon Komorek, Mariusz Cierech, and Elzbieta Mierzwinska-Nastalska. "Comparison of Mechanical Properties of a Self-Adhesive Composite Cement and a Heated Composite Material." Polymers 14, no. 13 (June 30, 2022): 2686. http://dx.doi.org/10.3390/polym14132686.

Full text

Abstract:

(1) Background: Due to the limitations of composite cements, the authors carried out tests to compare such materials with preheated composite materials because the latter may be an alternative to cements in the adhesive cementation procedure. (2) Methods: The materials used in the adhesive cementation procedure, i.e., Enamel Plus Hri (Micerium, Avegno, Italy), a heated composite material, and RelyX U200 Automix (3M, Maplewood, MN, USA), a dual composite cement, were tested for microhardness, compressive strength, flexural strength, diametral compressive strength, and elastic modulus. Composite material was heated to the temperature of 50 degrees Celsius before polymerisation. (3) Results: Higher values of microhardness (by 67.36%), compressive strength (by 41.84%), elastic modulus (by 17.75%), flexural strength (by 36.03%), and diametral compressive strength (by 45.52%) were obtained using the Enamel Plus Hri composite material compared to the RelyX U200 self-adhesive cement. The survey results revealed statistically significant differences. (4) Conclusions: Due to its better mechanical properties, the heated composite material (Enamel Plus Hri) is a beneficial alternative to composite cements in the indirect restoration placement procedure. As the strength parameters of the heated composite material increase, a higher resistance to the compressive and bending forces present in the oral cavity, and hence a greater durability of the created prosthetic reconstructions can be expected.

APA, Harvard, Vancouver, ISO, and other styles

44

Ratih, D. N., J. E. A. Palamara, and H. H. Messer. "Minimizing Dentinal Fluid Flow Associated with Gap Formation." Journal of Dental Research 85, no. 11 (November 2006): 1027–31. http://dx.doi.org/10.1177/154405910608501110.

Full text

Abstract:

The relationship between gap formation and outward fluid flow and procedures to minimize both phenomena were investigated in extracted human premolars restored in vitro with MOD composite restorations. We hypothesized that either glass-ionomer cement (GIC) liners or low-shrinkage composite could reduce fluid flow related to gap formation. Two groups restored with bonding agents with either high- or low-shrinkage resin composites, and 2 groups restored by either conventional or light-cured GIC liner plus resin composite were compared (8 teeth/group). Fluid flow was measured with an automated apparatus. Baseline fluid flow was low and unchanged after bonding, but increased sharply (though transiently) after teeth were lined with GIC. Outward flow was significantly greater with conventional than with light-cured GIC. Inward fluid flow occurred during light-curing, followed by extensive, prolonged outward flow after curing. Low-shrinkage composite or GIC liners reduced gap formation and limited outward fluid flow. GIC liners promoted outward fluid flow during their setting reactions. Abbreviations: GIC, glass-ionomer cement; CEJ, cemento-enamel junction; MOD, mesio-occluso-distal; SEM, scanning electron microscopy.

APA, Harvard, Vancouver, ISO, and other styles

45

Naumova, Ella, Felix Roth, Berit Geis, Christine Baulig, Wolfgang Arnold, and Andree Piwowarczyk. "Influence of Luting Materials on the Retention of Cemented Implant-Supported Crowns: An In Vitro Study." Materials 11, no. 10 (September 28, 2018): 1853. http://dx.doi.org/10.3390/ma11101853.

Full text

Abstract:

The retention force of cemented crowns on implant abutments with various luting materials was evaluated. Cobalt–chromium crowns were cemented onto tapered titanium abutments (Camlog) with eugenol-free temporary cement (RelyX TempBond NE), composite-based temporary cement (Bifix Temp), zinc phosphate cement (Harvard Cement), glass-ionomer cements (Meron, Fuji I), and resin-modified glass-ionomer cements (Fuji II, Fuji Plus, Ketac Cem Plus). Specimen aging via hydrostress was performed in artificial saliva at 37 °C for 14 days (S1), followed by hydrothermal stress with thermocycling (S2). The crowns were removed, and the force was recorded (T1). Subsequently, the crowns were recemented, aged, and removed, and the force was recorded (T2, T3). The retention forces differences were statistically significant according to the storage conditions at T1 (p = 0.002) and T3 (p = 0.0002). After aging (S1), Ketac Cem Plus had the highest retention force median value difference (T3 versus T1) (−773 N), whereas RelyX TempBond NE had the lowest (−146 N). After aging (S2), Meron had the highest retention force median value difference (−783 N), whereas RelyX TempBond NE had the lowest (−168 N). Recementation decreased the retention force of the implant-supported cobalt–chromium crowns cemented and recemented with the same luting materials. Luting materials (at T1) and aging conditions significantly impacted the retention force.

APA, Harvard, Vancouver, ISO, and other styles

46

Marques, Francisco Augusto Zago, Carlos Eduardo G. da Silva, André Luis Christoforo, Francisco Antonio Rocco Lahr, Túlio Hallak Panzera, and Rodrigo B. Canto. "Influence of Portland Cement Addition in the Physical and Mechanical Properties of Epoxy Resin." Advanced Materials Research 1088 (February 2015): 411–14. http://dx.doi.org/10.4028/www.scientific.net/amr.1088.411.

Full text

Abstract:

This research evaluated, with the of the analyses of variance (ANOVA), a composite material based on epoxy matrix phase reinforced with Portland cement (CP-II) particles (0%wt [100%wt of resin], 20%wt, 40%wt, 60%wt). The response-variable investigated were modulus of elasticity (E) and compressive strength (S), bulk density (ρB), apparent density (ρA) and porosity (P). The highest values of the modulus of elasticity were provided from the composites manufactured with 40wt% of cement addition. The inclusion of 60% of cement implies in a reduction in the mechanical properties when compared with the results of the composite manufactured with 40% of cement. For the physical properties, the gradually inclusion of cement provides increasing in the density of the composites, and reduce the porosity of the materials manufactured.

APA, Harvard, Vancouver, ISO, and other styles

47

Huang, Qian Yu, and Xiao Yu Zhang. "Finite Element Analysis of the Prestressed Composite Pipes." Applied Mechanics and Materials 687-691 (November 2014): 440–43. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.440.

Full text

Abstract:

This topic develop the matrix composite pipes which has the ability of corrosion prevention and antiseep, also has the high strength of extension and stability, by using huge advantage of the corrosion prevention and antiseep performance of resin matrix composite, the high strength of extension of carbon steel, and also, the high stiffness of cement matrix composites. We design and optimize the structure of matrix composite pipes by study the relationship between deformation coordination based on the viscoelastic constitutive model of resin matrix composite, the homogeneity elastic constitutive model of the cement matrix composites. We obtain a basic method of design the matrix composite pipes from studying from theoretical analysis and numerical simulation.

APA, Harvard, Vancouver, ISO, and other styles

48

Mune, Akash B., and K. S. Patil. "Investigation of Ferro Cement Composite Beam Under Flexure." Journal of Advances and Scholarly Researches in Allied Education 15, no. 2 (April 1, 2018): 419–26. http://dx.doi.org/10.29070/15/56858.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Kashif Ur Rehman, Sardar, Sabina Kumarova, Shazim Ali Memon, Muhammad Faisal Javed, and Mohammed Jameel. "A Review of Microscale, Rheological, Mechanical, Thermoelectrical and Piezoresistive Properties of Graphene Based Cement Composite." Nanomaterials 10, no. 10 (October 21, 2020): 2076. http://dx.doi.org/10.3390/nano10102076.

Full text

Abstract:

Extensive research on functionalized graphene, graphene oxide, and carbon nanotube based cement composites has been carried out to strengthen and overcome the shortcomings of construction materials. However, less literature is available on the pure graphene based cement composite. In this review paper, an in-depth study on a graphene-based cement composite was performed. Various structural forms of graphene and classifications of graphene-based nanomaterial have been presented. The dispersion mechanism and techniques, which are important for effective utilization in the construction industry, are reviewed critically. Micro-scale characterization of carbon-based cement composite using thermogravimetric analysis (TGA), infrared (IR) spectroscopic analysis, x-ray diffractometric (XRD) analysis, and morphological analysis has also been reviewed. As per the authors’ knowledge, for the first time, a review of flow, energy harvesting, thermoelectrical, and self-sensing properties of graphene and its derivatives as the bases of cement composite are presented. The self-sensing properties of the composite material are reported by exploring physical applications by reinforcing graphene nanoplatelets (GNPs) into concrete beams.

APA, Harvard, Vancouver, ISO, and other styles

50

Kazemi Babaheydari, A., M. Asad-Zadeh, and F. Mohammadi. "Nano Colorful Cement Composite." Applied Mechanics and Materials 313-314 (March 2013): 103–7. http://dx.doi.org/10.4028/www.scientific.net/amm.313-314.103.

Full text

Abstract:

The purpose of this study is to investigate the strength and mechanical properties of concrete by partial replacement of cement with nano-pigment particles. Nano-pigment particles with the average diameter of 120 nm were used with ten different contents of 0.5%, 0.1%, 1.5% and 4.0% by weight. have been investigated by scan electron microscopy(SEM) ,¬X-ray diffraction(XRD).The results showed that the use of nano- pigment particles up to maximum replacement level of 4.0% produces concrete with improved strength and mechanical properties The SEM study of the microstructures between the cement mortar mixed with the nano-pigment particles and the plain cement mortar showed that the nano-pigment particles as a partial replacement of cement up to 4 wt% could accelerate C–S–H gel formation as a result of the increased crystalline Ca(OH)2 amount at the early ages of hydration.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Cement composite'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles