scholarly journals Enhanced Mechanical Properties of Eucalyptus-Basalt-Based Hybrid-Reinforced Cement Composites

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2837
Author(s):  
Promoda Behera ◽  
Muhammad Tayyab Noman ◽  
Michal Petrů
Keyword(s):  
Flexural Strength ◽  
Physical Properties ◽  
Hybrid Composites ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Cement Composites ◽  
Volume Porosity ◽  
Reinforced Cement ◽  
Cement Matrices ◽  
Composite Samples

The present study describes the manufacturing of flat sheets of eucalyptus-basalt based hybrid reinforced cement composites (EB-HRCC). The potential of basalt fibrous waste (BFW) as a reinforcement agent in cement matrices and its effects on mechanical and interfacial properties were evaluated in detail. Significantly enhanced bending (flexural) strength and ductility were observed for all developed composite samples. BFW and eucalyptus pulp (EP) were utilized as reinforcement and filling agents respectively for EB-HRCC samples. Mechanical, microstructural and physical properties of EB-HRCC samples were investigated with different formulations of BFW with EP in cement matrices. The results showed that physical properties of the composite samples were more influenced by fiber content. For standard mechanical analysis, the composite samples were placed in sealed bags for two days, thermally cured at 60 °C for five days and immersed in water in ambient conditions for one day. The obtained results showed that samples prepared under optimized conditions (4% EP and 2% BFW) had significantly higher flexural strength and bulk density with lower water absorption and apparent void volume (porosity). Moreover, the higher percentage of BFW significantly enhanced the values of modulus of rupture (MOR), modulus of elasticity (MOE), specific energy (SE) and limit of proportionality (LOP). The effects of entrapped air under the four-point bending test on the mechanical behavior of hybrid composites were also investigated in this thematic study. The composites were designed to be used as roofing tile alternatives.

scholarly journals Nanocelluloses: Natural-Based Materials for Fiber-Reinforced Cement Composites. A Critical Review

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 518 ◽  
Author(s):  
Ana Balea ◽  
Elena Fuente ◽  
Angeles Blanco ◽  
Carlos Negro
Keyword(s):  
Raw Material ◽  
Modulus Of Rupture ◽  
Cement Matrix ◽  
Future Research ◽  
Cementitious Composites ◽  
Natural Material ◽  
Cement Composites ◽  
Fiber Reinforced ◽  
Industrial Sectors ◽  
Reinforced Cement

Nanocelluloses (NCs) are bio-based nano-structurated products that open up new solutions for natural material sciences. Although a high number of papers have described their production, properties, and potential applications in multiple industrial sectors, no review to date has focused on their possible use in cementitious composites, which is the aim of this review. It describes how they could be applied in the manufacturing process as a raw material or an additive. NCs improve mechanical properties (internal bonding strength, modulus of elasticity (MOE), and modulus of rupture (MOR)), alter the rheology of the cement paste, and affect the physical properties of cements/cementitious composites. Additionally, the interactions between NCs and the other components of the fiber cement matrix are analyzed. The final result depends on many factors, such as the NC type, the dosage addition mode, the dispersion, the matrix type, and the curing process. However, all of these factors have not been studied in full so far. This review has also identified a number of unexplored areas of great potential for future research in relation to NC applications for fiber-reinforced cement composites, which will include their use as a surface treatment agent, an anionic flocculant, or an additive for wastewater treatment. Although NCs remain expensive, the market perspective is very promising.

Physical Property Evaluation of Four Composite Materials

2013 ◽  
Vol 38 (5) ◽  
pp. E144-E153 ◽  
Author(s):  
M Chang ◽  
J Dennison ◽  
P Yaman
Keyword(s):  
Flexural Strength ◽  
Physical Properties ◽  
Vickers Hardness ◽  
Dwell Time ◽  
Testing Machine ◽  
Surface Hardness ◽  
Composite Resins ◽  
Bending Test ◽  
Polymerization Shrinkage ◽  
Hardness Tests

SUMMARY Purpose The purpose of this study was to evaluate the physical properties of current formulations of composite resins for polymerization shrinkage, surface hardness, and flexural strength. In addition, a comparison of Knoop and Vickers hardness tests was made to determine if there was a correlation in the precision between the two tests. Materials and Methods Four composite resin materials were used: Filtek LS (3M-ESPE), Aelite LS (Bisco), Kalore (GC America), and Empress Direct (Ivoclar). Ten samples of each composite (shade Vita A2) were used. Polymerization shrinkage was measured with the Kaman linometer using 2-mm-thick samples, cured for 40 seconds and measured with digital calipers for sample thickness. Surface microhardness samples were prepared (2-mm thick × 12-mm diameter) and sequentially polished using 600-grit silicone carbide paper, 9 μm and 1 μm diamond polishing solutions. After 24 hours of dry storage, Knoop (200 g load, 15 seconds dwell time) and Vickers (500 g load, 15 seconds dwell time) hardness tests were conducted. Flexural strength test samples (25 × 2 × 2 mm) were stored in 100% relative humidity and analyzed using a three-point bending test with an Instron Universal Testing Machine (Instron 5565, Instron Corp) applied at a crosshead speed of 0.75 ± 0.25 mm/min. Maximum load at fracture was recorded. One-way analysis of variance and Tukey multiple comparison tests were used to determine significant differences in physical properties among materials. Results Filtek LS had significantly lower shrinkage (0.45 [0.39] vol%). Aelite LS demonstrated the greatest Knoop surface hardness (114.55 [8.67] KHN), followed by Filtek LS, Kalore, and Empress Direct (36.59 [1.75] KHN). Vickers surface hardness was significantly greater for Aelite LS (126.88 [6.58] VH), followed by Filtek LS, Kalore, and Empress Direct (44.14 [1.02] VH). Flexural strength (MPa) was significantly higher for Aelite LS and Filtek LS (135.75 [17.35]; 129.42 [9.48]) than for Kalore and Empress Direct (86.84 [9.04]; 92.96 [9.27]). There is a strong correlation between results obtained using Knoop and Vickers hardness tests (r=0.99), although Vickers values were significantly greater for each material. Conclusion Results suggest that Aelite LS possesses superior hardness and flexural strength, while Filtek LS has significantly less shrinkage compared with the other composites tested.

Microstructure and Mechanical Performance of Fiber-Reinforced Cement Composites Made with Nucleating-Agent Activated Coal-Fired Power Plant Bottom Ash

2020 ◽  
Vol 302 ◽  
pp. 85-92 ◽  
Author(s):  
Passakorn Sonprasarn ◽  
Parinya Chakartnarodom ◽  
Nuntaporn Kongkajun ◽  
Wichit Prakaypan
Keyword(s):  
Mechanical Properties ◽  
Power Plant ◽  
Bottom Ash ◽  
Cellulose Fiber ◽  
Nucleating Agent ◽  
Modulus Of Rupture ◽  
Cement Composites ◽  
Fiber Reinforced ◽  
Activated Coal ◽  
Reinforced Cement

The purpose of this work was to study the microstructure and the mechanical properties of the fiber-reinforced cement composites that used the nucleating-agent activated coal-fired power plant bottom ash as a raw material in the mixture for producing the composites. The raw materials for producing the fiber reinforced cement composites were the ordinary Portland cement (OPC), natural gypsum, cellulose fiber, and bottom ash. The bottom ash was chemically treated by the nucleating agent, a chemical that was prepared by the precipitation process from the aqueous solutions of sodium silicate (Na2SiO3) and calcium nitrate (Ca (NO3)2). To prepare the samples, the mixture consisting of 34.75 wt% OPC, 34.75 wt% bottom ash, 25 wt% natural gypsum, and 5.5 wt% cellulose fiber was mixed with the nucleating agent at the amount of 0 to 4.5 % of OPC weight in the mixture, and water to form the slurry. Then, the samples were produced by filter pressing process and cured in the autoclave for 16 hrs at 180 °C, and 10 bars. The mechanical properties of the samples including modulus of rupture (MOR), modulus of elasticity (MOE), and toughness were characterized by the universal testing machine (UTM). The microstructures of the samples were observed by scanning electron microscope (SEM). The results showed that the utilization of nucleating agent affect the microstructure of the sample leading to the improvement in the mechanical properties of samples.

scholarly journals Effect of the Number of CFRP Prepregs and Roughness at the Bonding Area on the Spring-Back and Flexural Strength of Hybrid Composites of CFRP Combined with CR980

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1054
Author(s):  
Ji Hoon Hwang ◽  
Chul Kyu Jin ◽  
Hyung Yoon Seo ◽  
Chung Gil Kang
Keyword(s):  
Flexural Strength ◽  
Hybrid Composites ◽  
Metal Plate ◽  
Bending Test ◽  
Carbon Fiber Reinforced Plastic ◽  
Spring Back ◽  
Three Point Bending ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Bonding Area

Hybrid composites in which a CR980 metal plate was bonded on carbon-fiber-reinforced plastic (CFRP) were prepared. Hybrid composites were two types of CFRP/CR980 hybrid composites and CR980/CFRP hybrid composites. The properties of the hybrid composites according to surface roughness on CR980 plate and the laminating number of CFRP prepregs were analyzed. The spring-back or spring-go angles were also measured through the V-bending test of hybrid composites. In addition, a three-point bending test for the hybrid composites was conducted to measure the flexural strength. Spring-back occurred in the CFRP/CR980 hybrid composites, while spring-go was observed in the CR980/CFRP hybrid composites. Voids were not found at the bonding area of the CFRP and CR980. As the roughness at the bonding area increased, the flexural strength slightly increased. The higher the laminating number of the CFRP prepregs, the lower the deformation value. CFRP/CR980 was deformed more easily than CR980/CFRP.

Flexural strength of steel fibre-reinforced cement composites

1987 ◽  
Vol 22 (9) ◽  
pp. 3103-3110 ◽  
Author(s):  
P. S. Mangat ◽  
K. Gurusamy
Keyword(s):  
Flexural Strength ◽  
Steel Fibre ◽  
Cement Composites ◽  
Reinforced Cement

scholarly journals Flexural strength and modulus of elasticity of different types of resin-based composites

2007 ◽  
Vol 21 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Sinval Adalberto Rodrigues Junior ◽  
Cesar Henrique Zanchi ◽  
Rodrigo Varella de Carvalho ◽  
Flávio Fernando Demarco
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Filler Content ◽  
Hybrid Composites ◽  
In Vitro Study ◽  
Bending Test ◽  
Test Machine ◽  
Weight Content

The aim of the study was to test whether the filler composition of resin composites influences their flexural strength and modulus of elasticity. Flexural strength and modulus of elasticity were obtained through a three-point bending test. Twelve bar shaped specimens of 5 commercially available composites - Supreme (3M/ESPE), a universal nanofilled composite; Esthet-X (Dentsply), Z-250 (3M/ESPE), Charisma (Heraeus Kulzer), universal hybrid composites; and Helio Fill (Vigodent), a microfine composite - were confectioned according to the ISO 4049/2000 specifications. The test was performed after a 7-days storage time using a universal test machine with a crosshead speed of 1 mm/min. The filler weight content was determined by the ashing technique. The data obtained on the mechanical properties were submitted to ANOVA and Tukey test (p < 0.05). Pearson's correlation test was used to determine the correlation between the filler content and the mechanical properties. A weak but significant correlation between the mechanical properties evaluated and the filler weight content was observed (p < 0.000). The microfine composite presented the lowest filler weight and the lowest mechanical properties. Statistically different flexural strength and modulus of elasticity results were observed among the universal hybrid composites. The nanofilled composite presented intermediary results. Within the limitations of this in vitro study, it could be concluded that the filler content significantly interfered in the flexural strength and modulus of elasticity of the composites tested.

Coconut Fiber Reinforced Cement-Based Composites

2020 ◽  
Vol 302 ◽  
pp. 101-106
Author(s):  
Siriphorn Rabma ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Physical Properties ◽  
Water Absorption ◽  
Cement Paste ◽  
Room Temperature ◽  
Coconut Fiber ◽  
Reinforced Cement ◽  
Iron Mold ◽  
Scanning Electron

The aim of this research was to study the properties of cement reinforced with coconut fiber. The coconut fiber addition that uses in this research were 5, 10 and 15% by weight of cement. The cement paste and coconut fiber were mixed together and packed into an iron mold. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the water bath at 3, 7 and 28 days. After that, the physical properties i.e. water absorption and density were examined. The microstructure was characterized by scanning electron microscopy (SEM). The results showed the surfaces of the coconut fibers were not smooth, spread with nodes and irregular stripes, which is covered with substances and other impurities. The compressive strength and flexural strength were also investigated. From the results, the mechanical properties were decreased with increasing coconut fiber content due to reducing density and higher porosity and water absorption compared to non-fiber cement paste and physical properties of fiber had been flexibility and smoother caused poor binding with cement. The best compressive strength and flexural strength results were obtained with the percentages of coconut fiber as 5% which value as 26.67 N/mm2 and 5.08 N/mm2 respectively.

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