Journal articles on the topic 'Cement-base composite'
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1
Cheng, Xin, Shuang Shuang Liao, Shi Feng Huang, and Li Li Guo. "Influence of Base Thickness on Performance of 1-3-2 Piezoelectric Composite." Advanced Materials Research 123-125 (August 2010): 121–24. http://dx.doi.org/10.4028/www.scientific.net/amr.123-125.121.
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Sulphoaluminate cement and Lead Niobium-Magnesium Zirconate Titanate ceramic [P(MN)]ZT were used as matrix and functional phase respectively to fabricate 1-3-2 cement-based piezoelectric composites by dice and filling technique. The influences of base thickness on piezoelectric properties, electromechanical properties and acoustic impedance properties of the composites were discussed. The results show that as the base thickness increases, the piezoelectric stain factor d33 increases gradually, while the piezoelectric voltage factor g33 decreases. The planar electromechanical coupling coefficient Kp exhibits the trend of decrease, while the thickness electromechanical coupling coefficient Kt and acoustic impedance show the increasing trend. The mechanical quality factor Qm reaches the minimum (1.49) when base thickness is 2.00 mm. The results reveal that the 1-3-2 piezoelectric composite will be suitable for application by changing the base thickness.
2
Shaybadullina, Arina, Yuliya Ginchitskaya, and Olga Smirnova. "Decorative Coating Based on Composite Cement-Silicate Matrix." Solid State Phenomena 276 (June 2018): 122–27. http://dx.doi.org/10.4028/www.scientific.net/ssp.276.122.
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The designed is a cement-silicate coating based on liquid sodium glass and Portland cement, modified with a complex ultra-and nanodispersed additive that includes titanium dioxide, expanded perlite sand and a dispersion of multilayered carbon nanotubes. The advantage of the designed coating is the use of Portland cement as a silicizer instead of conventionally used zinc oxide. The presented cement-silicate coating is water resistant, steam and gas proof, has good adhesion to the base and an increased durability, providing 4-5 times longer service life than those of the existing analogs. The presence of multilayered carbon nanotubes in the coating leads to the absorption of technogenic electromagnetic emission, and ultradisperse titanium dioxide promotes self-cleaning of the coating surface due to the photocatalysis effect. Expanded pearlite sand makes the coating surface textured when applying it to the base. The cement-silicate coating is used for facades decorative finishing of buildings made of ceramic bricks, cement concrete and plastered surfaces.
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Ali, Saima, Xuemei Liu, Sabrina Fawzia, and David Thambiratnam. "Study of the Mechanical Performance of the Improved Multi-Layer Composites Under Drop Weight Impact Loads." International Journal of Structural Stability and Dynamics 20, no. 06 (June 2020): 2040002. http://dx.doi.org/10.1142/s0219455420400027.
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This study attempts to propose innovative multi-layer cement-based composites to have high impact resistance which could be used for runway. In this paper, the performances of two innovative multi-layer composite runway pavements using asphalt concrete-high strength concrete-cement-treated aggregate and asphalt concrete-high strength concrete-cement mortar in surface-base-subbase layer were evaluated under impact loads. ABAQUS/Explicit software was used to simulate loading condition and nonlinear stabilized runway pavement layers characteristics. In addition, a detailed parametric study was also carried out to explore the effects of the selected materials and load-related parameters in changing the performance of multi-layer composites. The findings of the study will be helpful to introduce protective multi-layer composite runway pavement and consequently to reduce the maintenance work of runway pavement.
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Bao, Wen Bo, Shao Feng Zhang, Gao Hao Di, Wei Wei Ji, and Li Hui Qu. "Dynamic Load Effects of PVA Tail Sand Cement Base Composite Materials." Applied Mechanics and Materials 518 (February 2014): 66–70. http://dx.doi.org/10.4028/www.scientific.net/amm.518.66.
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This paper studies that dynamic load affects mechanical properties of materials about composite tail ore different replacement rate, different PVA fiber volume content and different plate thickness. The phenomenon of the tests and results showed that:1) PVA tailings cement-based composite materials has low damage, strong integrity and strong energy dissipation under dynamic loading. 2) When the volume content is 2%, material resistance effect is best. 3) The study proves that 30 mm plate have good ductility and Size effect influence the material mechanics performance. 4) PVA tailings cement-based composite materials under dynamic loads ,as tailings content increases the performance indicators reduced. So the engineering applications recommended replacement rate of the tailings is 50%.
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Jiang, Min Zheng, Yu Xin Dai, Guang Ling Zhou, and Yan Peng Cao. "Study on Composite Material Mechanics Model of the Cement Loop Damage Mechanism in Destroyed Casing Well." Applied Mechanics and Materials 34-35 (October 2010): 1–6. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.1.
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Based on the rolling restoration ，the fiber-base body mechanics model is established using casing pipe as hollow fiber, cement loop and mother earth as complex base body during the repairing of destroyed casing well. The calculation formula of stress and displacement are deduced in fiber-base body according to the solid mechanics and discussed the effect of some physics quantity to displacement such as friction coefficient by way of calculation, and have deduced the calculation formula of the cement-loop damage length according to the principle of energy balance. Thus discussing the effect of the friction coefficient and degumming power to the damage of cement loop. The practical circumstances of scene indicate that it is reasonable to using this model to research the cement mantle damage mechanism.
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Yang, Yuxuan, Peng Xiao, Shanshan Xu, and Tong Wang. "Study on performance of old composite pavement reclaimed material in cement stabilized macadam base." E3S Web of Conferences 53 (2018): 01041. http://dx.doi.org/10.1051/e3sconf/20185301041.
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For the old composite pavement, there are two regeneration methods: the overall recycling asphalt pavement and the cement concrete pavement and the Stratified recovery. C-B-3 gradation and cement content of 5% were used. The total content of recycled aggregate is 0, 30%, 50%, 70% and 100% and the proportion of RA and RAP is about 1:2. Through compaction test， unconfined compressive strength test and dry shrinkage test, studying the feasibility of recycling composite pavement to cement stabilized macadam base. The results show that the strength of recycled cement stabilized macadam is generally higher than that of ordinary cement stabilized macadam. The strength of regenerated cement stabilized macadam can meet the strength requirements under most traffic volume of the highways in the standard. The gradation of the mixture by stratified recovery is more uniform and the quality of the mixture can be better controlled. The addition of NA has a negative effect on the dry shrinkage properties of recycled cement stabilized macadam. However, mixing RAP into recycled cement stabilized macadam can reduce the sensitivity of materials to water and enhance the dry shrinkage property of materials.
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Jiang, Ying Bo. "The Experimental Study on Microbe Corrosion Resistance Performance of Cement Based Composite Material." Advanced Materials Research 598 (November 2012): 328–31. http://dx.doi.org/10.4028/www.scientific.net/amr.598.328.
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Use artificial enhanced sewage to configurate accelerated corrosion fluids, do the research on the performance of cement based composite material to resistance microbiological corrosion in the aerobic and anaerobic environment under the condition of sewage, the compressive strength and corrosion resistant coefficient and mass loss as the evaluation index, reveals the performance of cement base composite material to resistance microbial corrosion under the action of artificial intensified sewage.
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Cook, P. A., and C. C. Youngson. "An in vitro Study of the Bond Strength of a Glass Ionomer Cement in the Direct Bonding of Orthodontic Brackets." British Journal of Orthodontics 15, no. 4 (November 1988): 247–53. http://dx.doi.org/10.1179/bjo.15.4.247.
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The shear/peel bond strength of a ‘no-mix’ composite orthodontic bonding resin was compared in vitro with that of a glass ionomer cement. The effect of pre-treatment of the enamel, with either phosphoric acid or polyacrylic acid, prior to using the glass ionomer cement was also assessed. The composite resin had a significantly higher bond strength than the glass ionomer cement. Simple prophylaxis and drying of the enamel achieved the best results when using the glass ionomer cement, whilst etching the tooth surface with phosphoric acid produced a significantly poorer bond to the enamel. Investigation of the site of failure showed the composite resin bonded very well to the tooth and less well to the bracket, whilst the glass ionomer adhered significantly better to the bracket base than to the tooth surface.
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Song, Xiao Ruan, Yu Ting Qu, Xiao Yun Zhang, Wei Niu, and Yu Feng Jiang. "Design and Analysis of the Support System for Cement-Base Formwork." Advanced Materials Research 374-377 (October 2011): 1249–53. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.1249.
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The cement-base composite formwork reinforced by FRP is developed to act as permanent construction formwork. Considering such properties as the minor stiffness out of the plain and the smaller bending resistance of the formwork, the matched cross support device is designed which can be recycled. In this paper, components of the support device and the corresponding functions are introduced, the technological process is described. By means of finite element program, the appropriate support distances of formwork during concrete placement are calculated, the stress and deformation performances are also analyzed. In the end, economic benefit and environment efficiency of the permanent formwork system are discussed. The above research results indicate the feasibility and economy of the support system, which present a gist for investigation and application of the permanent FRP cement composite formwork.
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Shan, Jing Song, Ning Zhang, and He Xue Fan. "The Study on the Asphalt Pavement with Composite Base." Advanced Materials Research 505 (April 2012): 468–73. http://dx.doi.org/10.4028/www.scientific.net/amr.505.468.
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Semi-rigid layer is widely used as the base in China. However, the structure has resulted in many premature distresses in asphalt concrete layer. In order to overcome the problem, the composite base is introduced which is composed by both flexible and chemically stabilized material. The internal stresses are calculated by linear multilayer elastic theory and then, a comparison of the stresses of asphalt pavement with semi-rigid base and composite base is provided. The result shows that the composite base composed by all, consisting of the asphalt treated layer, graded crushed stone and cement treated layer is more suitable structure to resist cracking and the structure also has good adaptability to heavy load.
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Li, Hao, Naren Fang, Xuancang Wang, Yang Fang, Xianghang Li, Chao Li, and Siyin Ding. "Load Transfer Efficiency Analysis and Void Evaluation of Composite Pavement Cement Concrete Slab." Advances in Materials Science and Engineering 2022 (March 27, 2022): 1–18. http://dx.doi.org/10.1155/2022/4490485.
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The void at the bottom of a cement concrete slab is a common problem of composite pavements. It is of great significance to evaluate the spring stiffness, void size, and soil base elastic modulus at the bottom of cement concrete slab timely and accurately for the maintenance and guarantee of the pavement performance. In this paper, the composite pavement at a joint is modeled and the load transfer mechanism is realized by using spring groups for simulating the dowels that connect the two slabs of the joint. A database is established based on a large number of simulation results of joint load transfer efficiency and voids and the changing law of load transfer efficiency of cement concrete slab reveals their relationship. Taking into consideration the spring stiffness, void size, and soil base elastic modulus, the void evalua\tion method of composite pavement cement concrete slab is established by using back propagation neural network algorithm. The results show that the void evaluation method can provide the void determination map with two parameters. The values of the two parameters can be determined by the deflection basin. After querying the Atlas, the void determination can be more accurate. The research results provide scientific guidance for the void identification of the composite pavement and can effectively extend the service life of the pavement.
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Endawati, Jul, and Lilian Diasti. "Wood Shavel Composites with Friendly Environment Based Binder." Advanced Materials Research 911 (March 2014): 23–29. http://dx.doi.org/10.4028/www.scientific.net/amr.911.23.
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Wood fiber has long been known as fiber reinforcement for concrete . Because of the availability and low cost of production, natural fiber has been used in less developed countries where conventional building materials are very expensive. Fiber added to cement composite for increasing toughness, strength, impact resistance and resistance to fire.In this study, initially it is expected to develop an environmentally matrix binder for the composite by utilizing fly ash as the largest proportion of the matrix binder, silica fume and limestone.Fillers used in this study are differentiated into sawdust and wood shavel. Wood shavel filler were on two condition : treated in base liquid and untreated. The particle size of the sawdust used for the composite were those retained on ≠ 0.60 mm sieve size, while wood shavelgradation was used as received.Results of the flow test of fresh mortar for the entire design matrix either without or with filler are very low, that do not meet the flow specification standard. The limestone matrix using 35 % by volume has a low compressive strength , as it acts as a diluent in the mixture. The optimized volume proportion of matrix composites is 12 % (filler) : 47 % (binder) : 41 % (water). This composite has a dimensional stability, compressive strength of 211.6 kg/cm2 > minimum requirement of cement board ( 150 kg/cm2 ), while the flexural strength 73.3 Kg/cm2 < provision of cement board ( 90-150 Kg/cm2 ) .The density of the composite boards is 1.28 gr/cm3, and this can be considered high, but this also causes the composite board difficult to be cut and installed. Most of the test results on the composite board referring to JIS A 5908 do not fit the provision for the cement boards, although the difference is not too great. Therefore, during the production, compaction and curing or post-production treatment need to be considered.
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Cheng, Xin, Dong Yu Xu, Shuang Shuang Liao, and Shi Feng Huang. "Influence of Base Thickness on Properties of 1-3-2 Connectivity Cement Based Piezoelectric Composite." Advanced Materials Research 306-307 (August 2011): 835–38. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.835.
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Sulphoaluminate cement and Lead Niobium-Magnesium Zirconate Titanate ceramic (PMN) were used as matrix and functional component to fabricate 1-3-2 piezoelectric ceramic-cement composites by dicing and filling method. The influences of base thickness on piezoelectric, dielectric and electromechanical coupling properties of the composites were analyzed and discussed. The results show that with increasing the base thickness, the piezoelectric stain factor d33 increases gradually, while the piezoelectric voltage factor g33 decreases. The relative dielectric factor εr decreases initially and then increases, while the dielectric loss tan δ increases initially and then decreases. When base thickness is 0.50 mm, εr has the minimum value of 1406. When base thickness is 3.00 mm, tan δ reaches the minimum value of 0.251. With increasing the base thickness, the planar electromechanical coupling coefficient Kp exhibits the decreasing trend, and the thickness electromechanical coupling coefficient Kt and acoustic impedance Z show the increasing trend.
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Rocha, Daniel Maranha da, João Maurício Ferraz da Silva, Liliana Gressler May, Maria Amélia Máximo Araújo, Rebeca Di Nicoló, and João Carlos Rocha. "Cuspal deflection of directly or indirectly restored teeth." Brazilian Dental Science 16, no. 4 (December 5, 2013): 34. http://dx.doi.org/10.14295/bds.2013.v16i4.899.
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<p><strong>Objective: </strong>The aim of this study was to evaluatethe cuspal deflection of teeth restored directlyand indirectly. <strong>Material and Methods: </strong>Fortysound maxillary premolar teeth were restoredwith composite and different base materials. Widemesial-occlusal-distal cavity preparations wereperformed, with isthmus width of one third of thedistance between the cuspal tips, 3 mm occlusaland a 5 mm interproximal preparation height. Theteeth were divided into 4 groups (n = 10), accordingto the restoration type: G1) GIC-DCR (1 mm glassionomer cement base and direct restoration usingnanoparticulate composite); G2) FL-DCR (1 mm baseof flowable composite resin and direct restorationusing nanoparticulate composite); G3) GIC-ICR(1 mm glass ionomer cement base and indirectrestoration using nanoparticulate composite GICbase); G4) FL-ICR (1 mm base of flowable compositeresin and indirect restoration using nanoparticulatecomposite). The specimens were submitted tocompressive load of 50 N on the buccal and lingualcusps, in a universal testing machine. The lingualcusp microstrain (με) measurements were executedby strain gauges. <strong>Results: </strong>The Kruskal-Wallis (5%)test was used and showed there were no significantdifferences among the microstrain values for the fourstudy groups (G1 = 1250; G2 = 1075; G3 = 1279;G4 = 937). <strong>Conclusion: </strong>It could be concluded thatthe restorative techniques and the bases employeddid not show any influences in cuspal deflection.</p><p>Keywords<br />Base materials; Cuspal defection; Composite resin; Direct restoration; Indirect restoration.</p>
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Akaki, Emílio, Herman S. Mansur, Lúcia H. Angelis, Barbara A. Castro, Henrique F. Valadão, Danielle B. Faria, and Fernanda C. Rezende. "SEM/EDX and FTIR Characterization of a Dental Resin Cement with Antibacterial Agents Incorporated." Key Engineering Materials 284-286 (April 2005): 391–94. http://dx.doi.org/10.4028/www.scientific.net/kem.284-286.391.
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The demand from patients for aesthetic in posterior teeth restoration has been increasing in recent years. As an alternative to metal alloy restorations used in posterior tooth, aesthetical materials such as ceramics have been more often utilized. Resin cement, a derivative from dental composite, based on the combination of bis-GMA and inorganic filler is used to fixate these ceramic restorations to posterior teeth. Similar to resin composite, incorporated antibacterial agents to resin cement can be an effective way to increase the aesthetic restoration durability. Resin cements C&B® (Bisco) and Fill Magic Dual Cement® (Vigodent) were used in the present study. For experimental resin cement, Triclosan was incorporated to the base cement paste. Samples were investigated by Scanning Electron Microscopy coupled to EDX microprobe (SEM/EDX) and FTIR spectroscopy. The results have demonstrated that the incorporation of antibacterial agents to resin cement is possible through the developed procedure.
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Tukhareli, V. D., E. E. Gnedash, and A. V. Tukhareli. "Heat-Resistant Composite Materials Based on Secondary Material Resources." Solid State Phenomena 299 (January 2020): 287–92. http://dx.doi.org/10.4028/www.scientific.net/ssp.299.287.
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Heat-resistant properties of the cement stone are provided by both high-temperature filler and the modified matrix on the basis of the Portland cement. For production of heat-resistant compositions as high-temperature filler, it is offered to use the secondary and accompanying products of production of carbide of silicon (SiC) and production wastes of the abrasive tools on a ceramic base. Increase in heat-resistant properties of the Portland cement knitting substance is offered to be solved by introduction to the structure of a cement composition of single substituted orthophosphate of calcium. The choice as an additive to the Portland cement a single substituted orthophosphate of calcium (double superphosphate) is proved by questions of safety measures and ecology, when using ortho-phosphoric acid and its salts for giving to cement compositions heat-resistant properties. The multicomponent composition of fine-grained concrete makes it possible to operate effectively the processes of forming the structure of cement stone at all stages of the technology, and to obtain materials with the most diverse set of properties. An introduction to the structure of a composite of 5% of filler of cyclonic dust of carbide of silicon, and a replacement of quartz filler by waste of abrasive production gave the increase of the compressive strength at 12%, bending strength for 36%. The thermal firmness increased by 3 times. An introduction to the structure of heat-resistant composition of single substituted orthophosphate of calcium (double superphosphate) in a number of 0.2% of the mass of cement allowed to increase the thermal firmness of structures to 20 heat exchanges (water, 800 oС).
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Song, Xiao Ruan, Xiao Zhu, Xiao Yun Zhang, Yong Mong Wang, Chao Yan, and Song Bing Xu. "Experiment Study on Deformation Properties of Composite Shear Wall Combined with Cement Formwork and Concrete under Static Load." Applied Mechanics and Materials 578-579 (July 2014): 325–30. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.325.
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A structure type of composite shear wall is presented, the both sides of which are reinforced cement composite layer and the middle layer of which is concrete. In order to verify the cooperative work performance of cement-base composite layer and concrete, static load tests were carried out. In the test, the deformation properties of composite shear walls and the development law of the strain of concrete and steel were studied. Meanwhile, a normal shear wall with the same conditions was tested and the corresponding natures of two types of shear wall were contrasted and analyzed. The test results prove that the composite shear wall has a good overall deformation behavior, and can, to some extent, slow down the process of wall stiffness degradation. The research production has provided a foundation for the further exploration to the working properties of the composite shear wall under cyclic loading.
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Ciavoi, Gabriela, Ruxandra Mărgărit, Liana Todor, Dana Bodnar, Magdalena Natalia Dina, Daniela Ioana Tărlungeanu, Denisa Cojocaru, Cătălina Farcaşiu, and Oana Cella Andrei. "Base Materials’ Influence on Fracture Resistance of Molars with MOD Cavities." Materials 14, no. 18 (September 12, 2021): 5242. http://dx.doi.org/10.3390/ma14185242.
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The aim of this study was to compare fracture resistance of teeth presenting medium-sized mesial-occlusal-distal (MOD) cavities using different base materials. Thirty-six extracted molars were immersed for 48 h in saline solution (0.1% thymol at 4 °C) and divided into six groups. In group A, the molars were untouched, and in group B, cavities were prepared, but not filled. In group C, we used zinc polycarboxylate cement, in group D—conventional glass ionomer cement, in group E—resin modified glass ionomer cement, and in group F—flow composite. Fracture resistance was tested using a universal loading machine (Lloyd Instruments) with a maximum force of 5 kN and a crosshead speed of 1.0 mm/min; we used NEXYGEN Data Analysis Software and ANOVA Method (p < 0.05). The smallest load that determined the sample failure was 2780 N for Group A, 865 N for Group B, 1210 N for Group C, 1340 N for Group D, 1630 N for Group E and 1742 N for Group F. The highest loads were 3050 N (A), 1040 N (B), 1430 N (C), 1500 N (D), 1790 N (E), and 3320 N (F), the mean values being 2902 ± 114 N (A), 972 ± 65 N (B), 1339 ± 84 N (C), 1415 ± 67 N (D), 1712 ± 62 N (E), and 2334 ± 662 N (F). A p = 0.000195 shows a statistically significant difference between groups C, D, E and F. For medium sized mesial-occlusal-distal (MOD) cavities, the best base material regarding fracture resistance was flow composite, followed by glass ionomer modified with resin, conventional glass ionomer cement and zinc polycarboxylate cement. It can be concluded that light-cured base materials are a better option for the analyzed use case, one of the possible reasons being their compatibility with the final restoration material, also light-cured.
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Bažantová, Zdeňka, Karel Kolář, Petr Konvalinka, Jiří Litoš, and Miroslav Petrtýl. "Controlled Hardening of Silicate Binders for the Optimization of High Performance Composites." Key Engineering Materials 722 (December 2016): 281–85. http://dx.doi.org/10.4028/www.scientific.net/kem.722.281.
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This paper describes the fundamental principles for the development of high performance composites applicable in severe condition. Studied composite is based on the advanced silicate matrix consisted of cement and suitable addition modifying mineral additives. Experimental work was focused on the study of the evolution of mechanical properties and determination of frost resistance of developed composite at early age, what is crucial parameter for quick reconstruction. Obtained results confirmed that the action of frost did not interrupted the process of hydration of developed binding system, because index of frost resistance determined on the base of studied mechanical properties had increasing trend during the freeze/thaw cycling. Present paper declares high potential of silicate binders for difficult application.
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Pavlova, I. P., and K. Yu Belomesova. "Theoretical approach to prescribing dosages basalt fiber for dispersed reinforcement of fine-grained cement composites on expanding binders." Vesnik of Yanka Kupala State University of Grodno. Series 6. Engineering Science 12, no. 2 (November 25, 2022): 91–102. http://dx.doi.org/10.52275/2223-5396-2022-12-2-91-102.
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In modern construction the use of basalt fiber as a reinforcing component of fine-grained cement composites is restrained by a number of factors. The main one is the dosage of basalt fiber, namely, the lack of a unified methodology for assigning the optimal amount of fiber introduced into the cement composite in order to increase its physical and mechanical properties. The purpose of this work is to develop a theoretically justified approach to the appointment of doses of basalt fiber, taking into account the peculiarities of formation of cement structure with subsequent experimental approbation. In the introduction, the relevance of the research is indicated. A transit zone has been singled out as a structural component. The specific features of structure formation and the effects accompanying the formation of the transition zone are indicated. Approaches for optimization of the transition zone properties have been suggested, including due to simultaneous introduction of expansive additives on the basis of high-base metakaolin and disperse reinforcement. Basalt fiber has been chosen as disperse reinforcement as a compatible material with cement stone, which has improved adhesion characteristics. And due to commensurability of diameter of a monofilament with diameter of a cement grain it allows realizing the concept of 3D-reinforcement at a microlevel. In the main part of the paper, a calculation model is proposed which is based on a hierarchical representation of the cement composite structure with the transit zone separated into a separate element forming a so-called “effective” filler together with the filler. In this case, the dosage of basalt fiber is assigned on the basis of the condition of reinforcing the active cement matrix while ensuring coverage of each monofilament with a dense layer of cement stone. Verification has been carried out taking into account the available own experimental data and the data of other researchers.
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Song, Xiao Ruan, Wei Niu, Wen Chao Shan, Xiao Zhu, and Yong Meng Wang. "Research on Static Performance of Composite Shear Wall with Insulation Layer." Applied Mechanics and Materials 470 (December 2013): 1039–44. http://dx.doi.org/10.4028/www.scientific.net/amm.470.1039.
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A new type of composite shear wall with insulation function is proposed, the inner layer of which is made of cement-base composite formworks produced by our research group in advance, and the outer layer of which is made of insulation formwork superposed with the cement formwork and insulation material. The space between the inner and the outer formwork is filled with concrete. Through the test of static loading in vertical and horizontal ways, bearing capacity, deformation properties, and failure modes of the composite shear wall, and cooperative work performance of the insulated formwork and concrete are studied. The static working performance of the composite shear wall with insulation is compared with that of the composite shear wall without insulation and the traditional shear wall, and some suggestions are put forward. The research results have proved that the sandwich-type composite shear wall with insulation is well-performed, which plays an important role in the future study and application.
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Budiman, Ismail, and Widya Fatriasari. "WET/DRY CYCLING AND THE EFFECTS OF FIBER LOADING ON THE MECHANICAL PROPERTIES OF CEMENT COMPOSITES MIXED WITH KRAFT PULP-FIBER FROM SENGON (Falcataria Mollucana) WOOD." Teknologi Indonesia 40, no. 2 (April 10, 2018): 116. http://dx.doi.org/10.14203/jti.v40i2.331.
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Recently, pulp fiber-cement composites have found a practical application in the commercial market to replace hazardous asbestos fibers. For exterior applications, the effects of cyclical wetting and drying on the performance of cement composites were studied. The objective of this study was to investigate the influence of filling wood fibers in cement composites prior to and after a wet/dry cycling treatment. The testing of kraft pulp fiber filling consisted of a 3, 5, and 7% of volume fraction of the composite. The target density and water to cement ratio of the composites produced was 1.5 gcm -3 , with a 0.50 base on weight, respectively. Cement composites were formed and pressed into a mold to the targeted dimensions of 30 cm × 2.5 cm × 2.5 cm (length × width × thickness) for 24hours, before they were removed from the mold. They were then subjected into two curing system conditions. First, the boards were immersed in a water tank at 18 ± 2 °C for 28 days and then tested for their mechanical properties. Secondly, the samples were immersed in the same conditions as before, but followed by a wet/dry curing cycling for 6 times before the mechanical properties were tested. Mechanical characteristics were observed according to ASTM C293-94 for flexural strength and ASTM C116-90 for compressive strength by using a Universal Testing Machine (UTM). The addition of pulp fiber and the wet/dry cycling treatment gave a significantly linear effect on the mechanical properties of composites. The higher amount of wood fiber filling in the cement composites resulted in a lower flexural and compressive strength of the composites. Furthermore, the wet/dry cycling treatment tended to lower the flexural strength, but not the compressive strength of the composites.
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Liu, Rui, Li Min Dong, Qing Feng Zan, Chen Wang, and Jie Mo Tian. "Physicochemical and Mechanical Properties of Composite of Chitosan Microspheres/Calcium Phosphate Cement." Key Engineering Materials 336-338 (April 2007): 1654–57. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.1654.
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The aim of this work is to improve the mechanical properties of calcium phosphate bone cement (CPC) by appending chitosan microspheres to CPC base. That chitosan degrades rapidly than bone cement has been proved by previous investigations. Porous CPC has low compressive strength because of the pores in it weakening the structure. Additive chitosan microspheres can improve the mechanical properties by bearing the compress with the CPC base and produce pores after degradation. This study investigates the effect of chitosan microspheres on the setting time, mechanical properties, phase evolution and morphology of CPC. The additive proportion of chitosan microspheres ranges from 0 wt% to 30 wt%. Compared with original CPC, the modified CPC has higher compressive strength, without significantly affecting the chemical properties. The phase composition of the CPC is tested by XRD. The microstructures of CPC are observed using SEM. The final setting times range from 5~15 minutes and can be modulated by using different liquid and powder (L/P) ratio.
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Huo, Zhipeng, Yuan Bai, and Xiangyu Li. "Preparation of Expanded Graphite and Fly Ash Base High Temperature Compound Phase Transition Heat Absorption Material and Its Application in Building Temperature Regulation." Science of Advanced Materials 12, no. 6 (June 1, 2020): 829–41. http://dx.doi.org/10.1166/sam.2020.3745.
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In this study, the product substance was pretreated with coal excrement as a raw product substance. Taking expanded graphite and paraffin as phase change product substances, expanded graphite and paraffin or coal excrement base high temperature compound phase transition thermal storage product substance were prepared by mixed sintering method. Firstly, the sintering mechanism of the composite should be deduced. In addition, XRD, TG-DSC and other analytical techniques were used to characterize the morphology and physical character of the product substances. In order to test the temperature regulation ability of the product substance, the composite product substance was fused with cement. The cement block added with composite product substance was taken as the research object, verify the performance of compound phase transition product substance on temperature regulation. In the experimental procedure, when phase change product substances' the proportion was less than 60%, the high temperature compound phase transition thermal storage product substances prepared were well-formed and had good crystallography, and the green body' various tissues were densely distributed. When the paraffin content was above 35 wt%, the external density, compressive strength, and cement blocks' thermal conductivity added with composite product substances increased significantly compared with ordinary expanded perlite cement blocks, which was suitable for building product substances' requirements. When the paraffin content reached 38 wt%, a temperature difference of 19.2 °C to 26.1 °C appeared in the composite product substance' corresponding cube space, indicating that room temperature can be adjusted by adding a certain phase change product substance.
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Li, Chao Fei, Guo Ping Chen, and Shui Wen Zhu. "Study on the Properties of Straw Fiber Reinforced Cement-Based Composite." Applied Mechanics and Materials 368-370 (August 2013): 997–1000. http://dx.doi.org/10.4028/www.scientific.net/amm.368-370.997.
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Plant fiber concrete in the cement base material (cement, mortar or concrete) to join the natural plant fiber, to form a new type of concrete, its advantages can improve the performance of concrete, concrete to reduce costs, save energy. Understanding straw fibers mixed with concrete, the variation in performance, with the same concrete than different content, physical and mechanical properties of the different shapes straw fiber concrete test analysis of the concrete compressive strength, splitting the variation of tensile strength, flexural strength, and economic aspects of performance, to provide a reference for further study of the straw fiber reinforced concrete and other performance and application.
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Huang, Zhi Qiang, Xin Meng Pi, and Fang Liang. "The Iron Ore Dosage of Cement Base Composite Material Mechanics Effect on the Performance of the Experimental Research." Applied Mechanics and Materials 226-228 (November 2012): 1751–54. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.1751.
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To study the problem of the relation between the performance of cement base composite material and the dosage of the iron ore. Because of the gradually reducing of natural sand, people will pay attention to the use of the iron ore. The study shows the effect of the iron ore dosage of cement base composite material on the performance based on this condition. We mix with different dosage of iron ore in the test. Try to do the flexural strength test and the flexural strength is the highest of all when the dosage of iron ore is 60%. At the same time try to analyse the energy and we find the energy needed in the process of fracture is highest when the dosage of iron ore is 60%. So we can choose the 60% the iron ore used in practical application instead of the natural sand.
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Ayudia, Thesi Kurnia, Kuswardani Susari Putri, and Ivony Fitria. "PERBANDINGAN KEBOCORAN MIKRO PADA RESTORASI RESIN KOMPOSIT MIKROFILLER DENGAN RESIN-MODIFIED GLASS IONOMER CEMENT (RMGIC) PADA KAVITAS KLAS V GIGI ANTERIOR." Andalas Dental Journal 3, no. 2 (December 3, 2015): 83–91. http://dx.doi.org/10.25077/adj.v3i2.54.
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Microleakage defined as the clinically undetectable passage of bacteria, fluids, molecules or ions between a cavity wall and the restorative material. Microleakage tends to occur in Class V cavities. It is caused by marginal adaptation which is more difficult in class V cavities. Microfiller composite resin is developed and indicated for areas that not require a large pressure. As the development of dental materials, it has been developed a composite resin base material that is known as resin-modified glass ionomer cement. This material has purposed to reduce the limitation of conventional glass ionomer cement and take the advantage of the composite resin material.
The aim of this study was to evaluate microleakage difference of microfiler composite resin restoration with resin-modified glass ionomer cement restorations in class V anterior teeth cavities. The methode of this study used experimental laboratory through in vitro process . Thirty two class V cavities were prepared on labial surfaces of extracted human anterior teeth. Samples were divided into two groups. Group I included sixteen samples that have had restorated with microfiller composite. Group II included sixteen samples that have had restorated with resin-modified glass ionomer cement. The samples were immersed into aquabides solution for 24 hours. After that, the samples were immersed into 1% methylene blue solution for 24 hours. All samples sectioned longitudinally and analyzed for microleakage as dye penetration using a stereomicroscope.
Student t-test were used for statistical analysis. The resulting data showed no significantly difference between two groups.
Key Word : Microleakage, microfiller composite resin, resin-modified glass ionomer cement (RMGIC), class V cavities.
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Ramos, NC, JN Luz, MC Valera, RM Melo, GSFA Saavedra, and E. Bresciani. "Color Stability of Resin Cements Exposed to Aging." Operative Dentistry 44, no. 6 (November 1, 2019): 609–14. http://dx.doi.org/10.2341/18-064-l.
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SUMMARY The aim of this study was to evaluate the color stability of light-cured and dual-cured resin cements after artificial accelerated aging. Ten specimens (6-mm diameter and 2-mm thickness) for each of five resin cements were prepared: GC (dual-cured cement, GCem), Vb (light-cured cement, Variolink II only the base), Vbc (dual-cured cement, Variolink II base with catalyst), VV (light-cured cement, Variolink Veneer), and FR (flowable resin composite, light cured). The samples were polished and stored in an accelerated artificial aging machine for 308 hours (160 klx), with cycles of 120 minutes under light and 60 minutes in the dark. All aging was carried out in distilled water at 37°C and light irradiation at 765 W/m2. The samples were evaluated in a spectrophotometer before and after aging, and results were calculated according to CIEDE2000. The data were statistically analyzed (one-way analysis of variance and Tukey test, 95% confidence). The results of ΔE00 were statistically significant for the type of cement (p<0.001), with differences among tested groups. Variolink II (base only and base + catalyst) and the flowable resin were the cements with the lowest color variations after the artificial accelerated aging. Considering the values ΔE00 of acceptability and perceptibility, none of the tested cements showed acceptable values.
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Chen, Mingsheng, Peng Liu, Dewen Kong, Yuan Li, Yao Chen, Gengyin Cui, Jingdong Wang, Ke Yu, and Ningbo Wu. "Performance Study and Multi-Index Synergistic Effect Analysis of Phosphogypsum-Based Composite Cementitious Material." Coatings 12, no. 12 (December 7, 2022): 1918. http://dx.doi.org/10.3390/coatings12121918.
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The application of phosphogypsum in building materials can consume waste phosphogypsum and reduce ecological pressure. In this study, building phosphogypsum was used as the base material, and fly ash, lime, cement, and other materials were added to explore the performance of phosphogypsum-based cementitious composite building materials via orthogonal experimental method. Variance analysis and multiple regression analysis were used to summarize the performance variation of these phosphogypsum-based composite cementitious materials. This work demonstrates that the building phosphogypsum content and the water-cement mass ratio are significant factors affecting the thermal conductivity and mechanical properties of these materials scanning electron microscopy (SEM) analysis showed that the mechanical properties and thermal insulation properties of the prepared phosphogypsum-based composite cementitious materials were good in the C-S-H gel system and ettringite formation uniform specimens. Regression analysis showed a significant relationship between the building phosphogypsum content, fly ash content in the supplementary cementitious material, lime content, water-cement mass ratio, compressive strength, and thermal conductivity. The compressive strength and the thermal conductivity were analyzed by the index membership degree. The comprehensive performance of the phosphogypsum-based composite cementitious materials was evaluated, and basic theoretical research into the use of the phosphogypsum-based composite cementitious materials in a building non-load-bearing wall was carried out.
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Giorgi, MCC, NMAP Hernandes, MM Sugii, GMB Ambrosano, GM Marchi, DANL Lima, and FHB Aguiar. "Influence of an Intermediary Base on the Microleakage of Simulated Class II Composite Resin Restorations." Operative Dentistry 39, no. 3 (April 1, 2014): 301–7. http://dx.doi.org/10.2341/12-210-l.
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SUMMARY The aim of this in vitro study was to qualitatively and quantitatively evaluate the microleakage of Class II cavities restored with a methacrylate-based composite (Filtek Z250, 3M ESPE) or silorane-based composite (Filtek LS, 3M ESPE), varying the application of an intermediary base, using a low-viscosity composite resin (Filtek Z350 Flow, 3M ESPE) or resin-modified glass ionomer cement (RMGIC) (Vitrebond, 3M ESPE) and no intermediary base (control groups). Sixty cavities were prepared on the proximal surfaces of bovine teeth and were randomly divided according to the experimental groups (n=10). Following the restorative procedures and thermocycling, the samples were immersed in methylene blue for two hours. The qualitative evaluation was made using a stereomicroscope, whereby two observers analyzed the infiltration level of the dye within the tooth/filling. Microleakage scores among the groups were compared using the Kruskal-Wallis test followed by the Mann-Whitney test (p≤0.05). The samples were then ground and the powder was prepared for quantitative analysis in an absorbance spectrophotometer. The results were statistically analyzed by analysis of variance and the Tukey test (p≤0.05). Results from the quantitative analysis showed that LS presented higher values of microleakage than did Z250. There was a significant difference between both composites concerning the intermediary materials, with the lowest values obtained using RMGIC as an intermediary base. Results from the qualitative analysis showed that there were no statistically significant differences between composites; however, there were significant differences for both composites concerning the intermediary materials, with the lowest values obtained using RMGIC as an intermediary. It is possible to conclude that using RMGIC as an intermediary base provided lower microleakage, indicating better sealing of the tooth-restoration interface.
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Jogl, Marcel, Pavel Reiterman, Ondřej Holčapek, Filip Vogel, Karel Kolář, and Jaroslava Koťátková. "Analysis of Mechanical Properties of a Fibre Composite Containing Secondary Raw Materials." Advanced Materials Research 1077 (December 2014): 129–34. http://dx.doi.org/10.4028/www.scientific.net/amr.1077.129.
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Fundamental tasks of material engineers are the application of materials, which can be manufactured from the less valuable materials with conservation or increasing of final properties, predominantly higher strength and durability. Present paper contributes to the category of experimental research of special composites development. Article describes the application of secondary raw materials for the production of special fibre-reinforced composite for high temperature application. These secondary raw materials are arising by the recycling of waste produced in the building industry or by the recycling of cast-off materials. Aim of performed experimental program was to prepare lightweight refractory materials based on aluminous cement with sufficient mechanical properties. Application of secondary raw materials could be interesting solution with environmental benefits. Investigation of new type of fire resistant composites were realized on the base mechanical properties determination after high temperature exposure.
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Huang, Zhe, Jinyu Xu, Binglin Leng, Weibo Ren, Sen Chang, Zhihang Wang, and Wei Xia. "Study on the Effects of Powder-Liquid Ratio and Cement Ratio on Mechanical Properties and Microscopic Characteristics of Polymer-Cement Composite." Advances in Civil Engineering 2021 (December 24, 2021): 1–17. http://dx.doi.org/10.1155/2021/3283680.
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This paper is about a study on the mechanical properties of a new polymer-cement composite (PCC) in constant elongation, tension, and shear. The study explored the effects of powder-liquid ratio and cement ratio on the mechanical properties of PCC through detecting the strength, deformation, and energy consumption of specimens under different powder-liquid ratios and cement ratios. In addition, scanning electron microscope and mercury injection apparatus were used for an in-depth analysis on the micromorphology and pore structure features of PCC under different powder-liquid ratios and cement ratios to explore the influence of powder-liquid ratio and cement ratio of the micromechanical properties of PCC. The results showed that, with the increase of powder-liquid ratio and cement ratio, the constant elongation adhesion strength of PCC decreased, and, at a high powder-liquid ratio (0.55) or a high cement ratio (0.5), the constant elongation adhesion strength of PCC completely disappeared. Meanwhile, with the increase of powder-liquid ratio and cement ratio, the tensile shear strength of PCC increased, while the deformation capacity of PCC decreased. The optimal ranges of powder-liquid ratio and cement ratio for PCC were 0.35–0.4 and 0.3-0.4, respectively. Furthermore, the increased powder-liquid ratio and cement ratio made the total pore volume decreased and pore structure refined, which improved the compactness of PCC, thus influencing the performance of PCC macroscopically. An achievement for the study is a flexible composite material, which was formulated with the polymer film as continuous base phase, as well as the inorganic composition and cement hydrates as dispersion phase. The material can effectively improve the economy and practicability of cementation of fissures for airfield pavement.
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Seibi, Abdennour C., Fatick Nath, Adedapo B. Adeoye, and Kaustubh G. Sawant. "Optimization of Cement–Rubber Composites for Eco-Sustainable Well Completion: Rheological, Mechanical, Petrophysical, and Creep Properties." Energies 15, no. 8 (April 8, 2022): 2753. http://dx.doi.org/10.3390/en15082753.
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To ensure well integrity, wellbore must be strongly cased using durable cement slurries with essential additives during downhole completion. The rubber materials that come from industrial waste are becoming extremely encouraged in the use as an additive in preparing cement slurries due to their growing environmental footprint. However, the proper design of cement slurry strongly depends on its rheological, mechanical, petrophysical, and creep properties, which can be altered by changing additives. This study aimed to examine the cement properties under alteration in different chemical admixtures to create efficient binding properties, and to estimate the optimum cement–rubber slurry composition for eco-sustainable completion. Three cement samples with different mesh sizes of the crumb rubber particles were prepared. This study examined the variation in rheological behaviors, elastic and failure characteristics, permeability, and creep behavior of the cement–rubber composites for petroleum well construction. The experimental study showed that the addition of 15% or more crumb rubber to the cement resulted in very thick slurries. Moreover, it was shown that the addition of crumb rubber with various particle sizes to the cement reduced the strength by more than 50%, especially for a higher amount of rubber added. It was also revealed that the addition of a superplasticizer resulted in an 11% increase in compressive strength. The results showed that cement–crumb-rubber composites with 12% by weight of cement (BWOC) represented the optimum composite, and considerably improved the properties of the cement slurry. Water-permeability tests indicated the addition of 12% BWOC with 200-mesh crumb rubber decreased the permeability by nearly 64% compared to the base cement. Creep tests at five different stress levels illustrated that the neat cement was brittle and did not experience strain recovery at all stress levels. Cement slurries with the largest rubber-particle size were elastic and demonstrated the highest amount of strain recovery. Finally, a relationship was established between the permeability, average strain, and mesh size of the rubber particles, which offered the strain recovery, satisfied the zonal isolation, and consequently reduced the microannulus problem to ensure the cement’s integrity.
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Arrondo, J. L. R., M. I. Collado, Soler I, R. Triana, and J. Ellacuria. "Setting Reaction of Polyacid Modified Composite Resins or Compomers." Open Dentistry Journal 3, no. 1 (September 16, 2009): 197–201. http://dx.doi.org/10.2174/1874210600903010197.
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The hardening of modified polyacid composite resins (compomers) and glass-ionomers have been studied using infrared spectroscopy. The acid-base reaction in Ketac-fil, a glass ionomer, was followed by the ratio between the COOH band located around 1715 cm-1 and that corresponding to COO- located around 1570 cm-1. The combination of infrared analysis and band narrowing treatments enable us to propose in the glass-ionomer two maturation steps. First, a very rapid equilibrium acid-base related, and second the cross-linking of polycarboxylate with the metal ions present in the cement. In compomers, a new reaction has been described involving polymerization induced by free radicals besides the two steps associated with the acid-base reaction. Using infrared spectroscopy and band narrowing techniques, it is shown that water is essential to complete the hardening process but no acid-base reaction is produced since the COO- band does not appear. The reaction associated with free radicals could be described as a polymerization of methacrylate monomers together with an aqueous dilution of the filling particles releasing different metal cations that would chelate with the polymer molecules to form a macromolecular structure.
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Zhao, Yi, Xuan Yang, Qingyu Zhang, Naixing Liang, Yangkai Xiang, and Min Qin. "Crack Resistance and Mechanical Properties of Polyvinyl Alcohol Fiber-Reinforced Cement-Stabilized Macadam Base." Advances in Civil Engineering 2020 (July 10, 2020): 1–15. http://dx.doi.org/10.1155/2020/6564076.
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A series of tests were carried out to evaluate crack resistance and mechanical properties of polyvinyl alcohol fiber-reinforced cement-stabilized macadam, which is widely used as pavement base or subbase composite material. Three series of cement-stabilized macadam mixtures with cement content of 3.2%, 3.6%, and 4.0% were prepared by incorporating four various contents (0, 0.6, 0.9, and 1.2 kg/m3) and lengths (12, 18, 24, and 30 mm) of polyvinyl alcohol fiber. The optimum polyvinyl alcohol fiber content, fiber length, and cement content were determined based on the mechanical properties of cement-stabilized macadam mixtures. Then, unconfined compressive strength test, compressive resilience modulus test, splitting strength test, flexural tensile strength test, drying shrinkage test, and temperature shrinkage test were carried out in this study. The results show that polyvinyl alcohol fiber-reinforced cement-stabilized prepared by optimum proportions (cement 3.6%, fiber content 0.9 kg/m3, and fiber length 24 mm) has good crack resistance. The incorporation of polyvinyl alcohol fiber can effectively improve compressive strength and splitting strength, while its effect on CRM of cement-stabilized macadam is not remarkable. The anti-dry-shrinkage property and anti-temperature-shrinkage property of the specimens are also drastically improved due to the reinforcement effect of polyvinyl alcohol fiber. Moreover, the crack resistance index is proposed to evaluate the crack resistance of materials. The crack resistance of PVA fiber-reinforced cement-stabilized macadam prepared by optimum proportions is improved by 44.4%. Consequently, the mechanical properties and crack resistance of cement-stabilized macadam are obviously improved by adding polyvinyl alcohol fiber.
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Drechsler, Astrid, Ralf Frenzel, Anja Caspari, Stefan Michel, Matthias Holzschuh, Alla Synytska, Marco Liebscher, Iurie Curosu, and Viktor Mechtcherine. "Surface Modification of Polymeric Fibers to Control the Interactions with Cement-Based Matrices in Fiber-Reinforced Composites." Key Engineering Materials 809 (June 2019): 225–30. http://dx.doi.org/10.4028/www.scientific.net/kem.809.225.
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There is evidence that the fiber-matrix interaction in fiber-reinforced cementitious composites is determined by the wettability and roughness of the fibers. Due to the high ionic strength in the hydrated cement, also the surface charge or acid/base behavior of the fibers is assumed to play a role. To create fibers with alkaline and acidic surface functionalities, water-insoluble poly (vinyl alcohol) fibers were permanently modified by adsorption of various polyelectrolytes. X-ray photoelectron spectroscopy, zeta potential, and contact angle measurements revealed acidic, alkaline or amphoteric fiber surfaces with advancing water contact angles between 34° and 58°. In a first step to study the interaction with cementitious materials, the interaction of these fibers with pore solution (the liquid phase of hydrated cement) and the adsorption of calcium ions on the fiber surface were investigated. The work will be continued by studying the fiber-matrix interaction in cementitious matrices and its influence on the composite strength.
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D'Souza, Henston, Pradeep Chengarra Veetil, Raina D'Souza, M. C. Noushad, and C. P. Faizal. "Evaluation of the leakage of bleaching materials through different bases into the root canal filling: an invitro study." Journal of Research in Dentistry 3, no. 4 (January 19, 2016): 752. http://dx.doi.org/10.19177/jrd.v3e42015752-762.
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AIM: The purpose of this study was to evaluate the leakage of bleaching agents through 3 different bases into the obturated pulp space and dentinal tubules in intra coronal bleaching. MATERIAL AND METHODS: Fifty-five freshly extracted, intact non-carious single rooted teeth were collected and stored in formalin until used. The specimen divided into experimental and control group. Experimental group were further subdivided into 3 subgroups on the base of cervical base materials. Group I was Type II GIC, Group II was Fuji II LC and Group III was Hybrid composite. The control groups was divides into negative group (received the bleaching agent and received complete external coating including access cavity) and positive control group (did not receive any external coating). The obturated pulp space were removed at a level of 3 mm below the cemento enamel junction and filled with dry cotton pellets and temporized with temporary cement, stored at ± 37°C and 100% relative humidity for five days, the bleaching material were placed in the pulp chamber (a paste of sodium perborate i.e. 0.15g and 30% hydrogen peroxide 0.05ml), and then stored for 3 days in an incubator. Later on the teeth were immersed in India ink dye and stored at ± 37°C and 100% relative humidity for 5 days. Specimens were examined under binocular microscope with a stage micrometer to analyze the degree of dye penetration. RESULTS: The minimal leakage values were observed with type II glass ionomer cement followed by light cure glass ionomer cement and lastly by hybrid composite. CONCLUSION: The present invitro investigation evaluated the microleakage observed with different cervical base materials during non-vital bleaching procedures.
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Becker, Mirco. "Felt-Concrete Composites in Architecture and Design." Open Conference Proceedings 1 (February 15, 2022): 115. http://dx.doi.org/10.52825/ocp.v1i.84.
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The paper explores the possibilities of a composite of needle-felt fibres and cement-based matrix for designing and fabricating architectural elements. It summarizes the longer standing design-research undertaking in needle-felting as a novel method for creating materially graded objects without the use of formwork. The work is conducted on a design prototype of a chair to emphasise the integrative nature of this material system. This approach allows the study of all aspects from the fabrication process, the function of details, structural behaviour, and user experience.
Needle fleeting has a long tradition in arts and craft for manually forming intricate objects such as figurines or applying ornaments to textile objects. The main feature of felt material is that it can bring fibrous material into a stable shape. This process has been digitized by Disney Research proposing needle felting as a way of 3D-printing fibrous material[1]. Becker et al. also proposed a robotic process for robotically 3D-printing felt shapes [2] which form the base for a material composite of felt-fibers and a cement based matrix. Their paper argues for functionally graded architectural elements where the composite of felt and cement can provide for tensile reinforcement, compressive strength, insulation, and different haptic surfaces. Based these methods here a replica of IKEA® Leifarne chair is realized, showcasing a range of felt-concrete composite applications integrated in a single object.
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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.
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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.
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Brackett, M. G., A. R. Kious, and W. W. Brackett. "Minimally Retentive Gold Onlays: A Six-Year Case Report." Operative Dentistry 34, no. 3 (May 1, 2009): 352–55. http://dx.doi.org/10.2341/08-50.
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PURPOSE Partial veneer gold restorations, such as gold onlays, have changed little in preparation design over the past 40 years, as evidenced by textbooks that have long been in print.1–2 Such designs must have been based on the assumption that restorations would be luted with zinc phosphate cement but have not altered, despite the introduction of stronger luting cement classes, such as resin composite and resin-modified glass ionomer cements.1 It is well-established that both porcelain and base metal materials, which have been etched on the intaglio surface, can be combined with resin composite luting cements to produce restorations retained largely through adhesion. However, neither of these materials can equal the combination of minimal tooth reduction and margin adaptation that is possible with high noble gold restorative materials. Although high noble gold alloys cannot be etched, air abrasion of the intaglio surface of restorations likely improves micromechanical retention, but it is unknown whether this, along with a strong luting cement, is sufficient to stabilize high noble gold alloys in preparations with considerably less retention and resistance form than traditional designs.
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van de Sande, Françoise H., Paulo A. Da Rosa Rodolpho, Gabriela R. Basso, Rômulo Patias, Quéren F. da Rosa, Flávio F. Demarco, Niek J. Opdam, and Maximiliano S. Cenci. "18-year survival of posterior composite resin restorations with and without glass ionomer cement as base." Dental Materials 31, no. 6 (June 2015): 669–75. http://dx.doi.org/10.1016/j.dental.2015.03.006.
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Małek, Marcin, Waldemar Łasica, Marta Kadela, Janusz Kluczyński, and Daniel Dudek. "Physical and Mechanical Properties of Polypropylene Fibre-Reinforced Cement–Glass Composite." Materials 14, no. 3 (January 30, 2021): 637. http://dx.doi.org/10.3390/ma14030637.
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In accordance with the principles of sustainable development, environmentally friendly, low-emission, and energy-intensive materials and technologies, as well as waste management, should be used. Concrete production is responsible for significant energy consumption and CO2 production; therefore, it is necessary to look for new solutions in which components are replaced by other materials, preferably recycled. A positive way is to use glass waste. In order to determine the effect of a significant glass cullet content on the properties of concrete, glass powder was used as a filler and 100% glass aggregate. The cement–glass composite has low tensile strength and brittle failure. In order to improve tensile strength, the effects of adding polypropylene fibres on the mechanical properties of the composite were investigated. With the addition of 300, 600, 900, 1200, and 1500 g/m3 of fibres, which corresponds to 0.0625%, 0.1250%, 0.1875%, 0.2500%, and 0.3125% of cement mass, respectively, flexural strength increased compared with the base sample by 4.1%, 8.2%, 14.3%, 20.4%, and 26.5%, respectively, while the increase in splitting strength was 35%, 45%, 115%, 135%, and 185%, respectively. Moreover, with the addition of fibres, a decrease in slump by 25.9%, 39.7%, 48.3%, 56.9%, and 65.5%, respectively, compared with the reference specimen was determined.
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Kharchenko, Alexey I., Vyacheslav A. Alekseev, Igor Ya Kharchenko, and Andrey A. Alekseev. "Application of slag-alkali binders in jet cement grouting for soil consolidation." Vestnik MGSU, no. 6 (June 2019): 680–89. http://dx.doi.org/10.22227/1997-0935.2019.6.680-689.
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Introduction. The study proves actuality of the problem connected with obtaining efficient slag-alkali binders for usage in soil jet cement grouting. Replacement of usual portland cement for a slag-alkali binder in geotechnical underground construction activities allows solving a problem of waste (slag) utilization and increase economic efficiency of the soil jet cement grouting. In view of cement grouting technology features and possibility of usage cementation mixtures with various engineering characteristics for different soil types, a broad nomenclature of slag-alkali compositions can be used for obtaining soil-concrete structures. Materials and methods. Different types of slag were studied as constituents of composite binders. The PTs 500 D0 cement was taken as the basic portland cement. Standard requirements for cementation mixtures of mixing and pump facilities for soil-concrete bodies became the criteria. Investigations of hydration and structure formation during hardening of slag-alkali binders and soil-concretes on their base were conducted using a system of physical and chemical methods. Evaluation of construction and engineering properties of the composite slag-alkali binder was accomplished in accordance with the methods as per GOST 10181-2014 and GOST 5802-86 state standards. Results. Results of analysis how the slag type and amount influence the physical and mechanical properties of the binder used for jet soil cementation are presented. The article shows improvement of physical, mechanical, process and usage properties of the slag-alkali binder. General mechanism of impact of the slag on properties of the cementation mixture were revealed. Conclusions. Efficiency of application of the slag as an active component of the composite binder for jet cementation in geotechnical construction was theoretically substantiated and experimentally demonstrated. General applicability of the obtained concrete mixture based on the slag-alkali binder is stated for usage in cementation methods of improvement of technical parameters of concrete mixture and concretes. A classification of expanding cements possessing various expansion degrees was suggested for solving different construction problems.
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Wu, Bo, Xiaohai Xu, Shigang Luo, Dedao Yan, Kai Song, Xiang Zhang, and Fang He. "Study on the Mechanical Properties and Strengthening Mechanism of Interface-Modified Carbon Fiber Mesh Reinforced Cement-Based Composites with SCA&HMC." Molecules 24, no. 21 (November 5, 2019): 3989. http://dx.doi.org/10.3390/molecules24213989.
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Carbon fiber mesh reinforced cement-based composites (CMCCs) have received extensive attention in the field of engineering repair and structural reinforcement due to their outstanding properties such as two-way force, rust prevention, high specific strength, and low base surface requirements. However, the development of this material has been slowed down to some extent due to the poor interfacial bonding between the carbon fiber mesh and the cement matrix. In this paper, a novel fabrication strategy was proposed in which the carbon fiber mesh was modified with epoxy resin and silane coupling agent (SCA) to increase its surface chemical activity. Meanwhile, the hydroxymethyl cellulose (HMC) was also filled into the concrete matrix to improve the mechanical strength of the matrix as well as the load transfer behaviors between the mortar and carbon fiber (CF) mesh. The potential to employ SCA and HMC was evaluated for the making of CMCCs via the above methods. The results showed that the longitudinal shear strength of composites with SCA and SCA&HMC increased by 26.6% and 56.1% compared to those of CF with epoxy resin (EP) reinforced composites, respectively. The flexural strength of composite with SCA&HMC increases by 147.6% compared to I-(F) without CF. The novel II-HCM&CF/EP-SCA composites with excellent performance are promised to be applied in practical uses.
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Nešpor, Bohdan, and Martin Nejedlík. "Development of Electrically Conductive Composite Sensors with the Addition of Functional Fillers." Solid State Phenomena 272 (February 2018): 34–40. http://dx.doi.org/10.4028/www.scientific.net/ssp.272.34.
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The paper presents the development results of "smart" pressure-sensitive fibre-cement compositematerials as well as thin-film coating sensors designed to detect disruptions of the base materialstructure. Basic material characteristics of fine-grained and coarse-grained cement matrices wereacquired during the research. The benefits and influence of conductive inorganic components,metallic components in the form of iron fillings and steel wires, and last but not least carbon-basednon-metallic fibrous reinforcement, have been verified. Thin-film epoxy resin coatings were enrichedwith amorphous carbon black, multi-walled carbon nanotubes (MWCNT) and natural micronizedgraphite. The article closely describes the measurement of electrical and electro-mechanical(piezoresistive) properties of conductive fibre-cement composites and thin-film organic coatings in anon-loaded state, during static loading and especially during dynamic ballistic and shock tests on thefall tower. Specific electrical characteristics and the course of change in electric conductivity wasexpressed as electrical resistivity (the real component of the impedance).The performed experiments confirmed excellent electrical conductivity of dense steel-fibrereinforced composites and graphite-doped hybrid fibre reinforced concrete. The coatings showedsignificant and permanent changes in impedance in the order of tens of ohms. The newly developedfibre composites and coating layers change the impedance during destructive and non-destructivedynamic loading tests. The impedance changed not only during failure of the matrix, but also in thecase of indirect impact. Moreover, carbon reinforced concrete with incorporated graphite showedsome piezoresistive properties. These detection materials were intended to be part of a ballistic-resistant monitoring system.
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Kurpińska, Marzena, Beata Grzyl, Marek Pszczola, and Adam Kristowski. "The Application of Granulated Expanded Glass Aggregate with Cement Grout as an Alternative Solution for Sub-Grade and Frost-Protection Sub-Base Layer in Road Construction." Materials 12, no. 21 (October 28, 2019): 3528. http://dx.doi.org/10.3390/ma12213528.
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The purpose of the research was to assess the possibility of using granulated expanded glass aggregate (GEGA) with cement grout as a replacement of a sub-grade and frost-protection layer, made of natural fine aggregates (NATU), stabilized with a hydraulic binder. Instead of traditional parts of the road construction, such as the sub-grade and frost-protection layer with the application of fine aggregate, stabilized with cement, the authors propose only one layer, made of lightweight water-permeable material, containing GEGA with a grain size from 8 to 11.2 mm. In the article the authors present the physical properties of the materials, applied for the road layers, the properties of the fine aggregate, stabilized with cement, and those of the cement composite with GEGA as an alternative solution. The laboratory test results of fine aggregates, stabilized with cement and of cement composites with GEGA, are presented. Porosity, volume density, compressive strength, and frost resistance are being researched. The results of those tests are meant to play an essential role in designing the thickness of road layers. Different types of pavement structure (asphalt and concrete) and different values of road load are being considered in the given work. The paper is concluded with considerations on an innovative solution, involving the use of ecological materials.
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Debs, M. K. El, and E. K. Bellucio. "Cement-base bearing pads mortar for connections in the precast concrete: study of surface roughness." Revista IBRACON de Estruturas e Materiais 5, no. 1 (February 2012): 39–67. http://dx.doi.org/10.1590/s1983-41952012000100005.
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Bearing pads are used in precast concrete connections to avoid concentrated stresses in the contact area between the precast elements. In the present research, the bearing pads are Portland cement mortar with styrene-butadiene latex (SB), lightweight aggregate (expanded vermiculite-term) and short fibers (polypropylene, glass and PVA), in order to obtain a material with low modulus of elasticity and high tenacity, compared with normal Portland cement mortar. The objective of this paper is to analyze the influence of surface roughness on the pads and test other types of polypropylene fibers. Tests were carried out to characterize the composite and test on bearing pads. Characterization tests show compressive strength of 41MPa and modulus of elasticity of 12.8GPa. The bearing pads tests present 30% reduction of stiffness in relation to a reference mortar. The bearing pads with roughness on both sides present a reduction up to 30% in stiffness and an increase in accumulated deformation of more than 120%, regarding bearing pads with both sides smooth.
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Nguyen, KV, RH Wong, J. Palamara, and MF Burrow. "The Effect of Resin-modified Glass-ionomer Cement Base and Bulk-fill Resin Composite on Cuspal Deformation." Operative Dentistry 41, no. 2 (March 1, 2016): 208–18. http://dx.doi.org/10.2341/14-331-l.
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SUMMARY Objectives: This study investigated cuspal deformation in teeth restored with different types of adhesive materials with and without a base. Methods: Mesio-occluso-distal slot cavities of moderately large dimension were prepared on extracted maxillary premolars (n=24). Teeth were assigned to one of four groups and restored with either a sonic-activated bulk-fill resin composite (RC) (SonicFill), or a conventional nanohybrid RC (Herculite Ultra). The base materials used were a flowable nanofilled RC (Premise Flowable) and a high-viscosity resin-modified glass-ionomer cement (RMGIC) (Riva Light-Cure HV). Cuspal deflection was measured with two direct current differential transformers, each contacting a buccal and palatal cusp. Cuspal movements were recorded during and after restoration placement. Data for the buccal and palatal cusp deflections were combined to give the net cuspal deflection. Results: Data varied widely. All teeth experienced net inward cuspal movement. No statistically significant differences in cuspal deflection were found among the four test groups. Conclusions: The use of a flowable RC or an RMGIC in closed-laminate restorations produced the same degree of cuspal movement as restorations filled with only a conventional nanohybrid or bulk-fill RC.
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HOTTA, M., and M. AONO. "Adaptation to the cavity floor of the light-cured glass ionomer cement base under a composite restoration." Journal of Oral Rehabilitation 21, no. 6 (June 8, 2007): 679–85. http://dx.doi.org/10.1111/j.1365-2842.1994.tb01183.x.
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As, Albadah, and Khan Am. "An in Vitro Study Comparing Nano-Composite Microleakage with and without Hydroxyapatite-Reinforced Glass Ionomer Cement and Cention N as a Base Material in Class I Cavity." Pakistan Journal of Medical and Health Sciences 16, no. 5 (May 29, 2022): 400–402. http://dx.doi.org/10.53350/pjmhs22165400.
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Aim: This study assessed microleakage in class one cavities in premolar teeth treated with Nano-composites using Cention N and Hydroxyapatite reinforced Glass ionomer cement as a base. Materials and Methods: In Sixty premolars, Class I cavities, one-fourth the intercuspal distance wide and 0.5-1mm deep were formed. Three groups were made. Group 1 received only Nano-Composites, Group 2, Nano-Composites with Cention N, and Group 3, Nano-Composites with Hydroxyapatite reinforced GIC was used as a base material. After 24 hours in distilled water, samples were undergone 5000 thermocycles at 5°C to 55°C. Samples were dried, and apical surfaces were sealed and saved for a 1mm wide zone around the restoration margins. Teeth were coloured with 2% Methylene blue. All the teeth were longitudinally sectioned and examined under a microscope Results: The least microleakage and internal gaps with GIC reinforced by Hydroxyapatite used as a base material (1.03± 0.832), followed by Nanocomposites. (2.08 ± 1.347). However, the greatest microleakage was observed with Cention N when used as a base (2.60 ± 0.928). A strong positive correlation was also observed between microleakage and internal gap formation. Conclusion: Cention N demonstrated the maximum microleakage as a base material, followed by Nanocomposite. GIC with Hydroxyapatite as a base material showed the least microleakage. Keywords: Cention N, GIC reinforced by Hydroxyapatite, Nanocomposite, base material, Microleakage