Improvement of biocomposite performance under low-velocity impact test - a review

2nd World Conference on Advanced Materials for Defense, AUXDEFENSE 2020Virtual, Online6 July 2020 through 7 July 2020Code 266239The study of the impact energy and the composite behaviour plays a vital role in the efficient design of composite structures. Among the various categories of impact tests, it is essential to study low-velocity impact tests as the damage generated due to these loads is often not visible to the naked eye. The internal damages can reduce the strength of the composites and hence the impact behaviour must be addressed specifically for improving their applications in the transport industry. The main aim of this paper is to provide a comprehensive review of the work focusing on the assessment of biocomposites performance under low impact velocity, the different deformations, and damage mechanisms, as well the methods to improve the impact resistance.(undefined

Mechanical and physical performance of low alkalinity cementitiouscomposites reinforced with recycled cellulosic fibres pulp fromcement kraft bags

The objective of this work was to study the addition of cellulosic pulp in low alkalinity cement composites as well as its mechanical behavior under bending stresses before and after accelerated aging cycles.The cellulosic pulp was obtained from recycled Portland cement kraft bags used for packaging. Lowalkaline cementitious matrices were tested, reducing from 80 to 85% the content of Portland cement, inorder to reduce the use of the conventional raw materials, energy cost and mainly to avoid a possiblealkaline degradation of the cellulosic pulps. The cement matrix resulted from the ternary blend Portlandcement gypsum pozzolan (fly ash or catalytic cracking catalyst residue), with 50% by weight of gypsumand different percentages by weight of pozzolans. These composites were prepared in the laboratory usinga slurry vacuum dewatering followed by pressing technique. The four point-bending tests were carriedout to evaluate the mechanical behavior of the low alkalinity cementitious composites and compositewithout pozzolans at 28 days and after soak and dry accelerated aging tests. The low alkaline cementcomposites presented average values of modulus of rupture about 10 MPa after the aging cycles, with theindication that its flexural strength was not significantly affected by the degradation tests. In addition, theaverage values of specific energy of these composites were also acceptable after 100 soak and dry cyclesas compared to the composites with the Portland cement plain matrix. These results suggest that theuse of low alkalinity ternary binder system can be an effective contribution in order to avoid the severedamage on cellulosic fibers (which occurred when traditional pure Portland cement matrix is applied).Authors would thank International Relationship Department of the Universitat Politecnica de Valencia for the scholarship awarded and to the financial support and scholarships provided by Brazilian Agencies Fapesp and CNPq for the work carried out at FZEA USP Pirassununga.Marmol De Los Dolores, G.; Santos, SF.; Savastano, HJ.; Borrachero Rosado, MV.; Monzó Balbuena, JM.; Paya Bernabeu, JJ. (2013). Mechanical and physical performance of low alkalinity cementitiouscomposites reinforced with recycled cellulosic fibres pulp fromcement kraft bags. Industrial Crops and Products. 49:422-427. doi:10.1016/j.indcrop.2013.04.051S4224274

Compósitos de baixa alcalinidade à base de óxido de magnésio reforçados com fibras de celulose

A lower-alkalinity cement based on MgO and SiO2 blends is analysed to develop clinker-free Fibre Reinforced Cementitious Composites (FRCC) with cellulosic fibres in order to solve the durability problems of this type of fibres when used in FRCC with Portland cement. Hydration evolution from 7 to 28 days of different MgO-SiO2 formulations is assessed. The main hydration products are Mg(OH)2 and M-S-H gels for all the formulations studied regardless of age. Hardened pastes are obtained with pH values < 11 and good mechanical properties compared to conventional Portland cement. 60% MgO-40% SiO2 system is chosen as optimal for the development FRCC since is the most mechanical resistant and is less alkaline compared with 70% MgO-30% SiO2. FRCC based on magnesium oxide and silica (MgO-SiO2) cement with cellulose fibres are produced to study the durability of lignocellulosic fibres in a lower pH environment than the ordinary Portland cement (PC). Flexural performance and physical tests (apparent porosity, bulk density and water absorption) of samples at 28 days and after 200 accelerated ageing cycles (aac) are compared. Two types of vegetable fibres are utilised: eucalyptus and pine pulps. MgO-SiO2 cement preserves cellulosic fibres integrity after ageing, so composites made out of MgO-SiO2 exhibit significant higher performance after 200 cycles of accelerated ageing than Portland cement composites. High CO2 concentration environment is evaluated as a curing treatment in order to optimise MgO- SiO2 matrices in FRCC. Samples are cured under two different conditions: 1) steam water curing at 55°C and 2) a complementary high CO2 concentration (20% by volume). In carbonated samples, Mg(OH)2 content is clearly lowered while new crystals of hydromagnesite [Mg5 (CO3)4⋅(OH) 2⋅4H2O] are produced. After carbonation, M-S-H gel content is also reduced, suggesting that this phase is also carbonated. Carbonation affects positively to the composite mechanical strength and physical properties with no deleterious effects after ageing since it increases matrix rigidity. The addition of sepiolite in FRCC is studied as a possible additive constituent of the binding matrix. Small cement replacement (1 and 2% wt.) by sepiolite is introduced and studied in hardened cement pastes and, later, in FRCC systems. When used only in cement pastes, it improves Dynamic Modulus of Elasticity over time. Bending tests prove the outcome of this additive on the mechanical performance of the composite: it improves composite homogeneity. Ageing effects are reported after embedding sisal fibres in MgO-SiO2 and PC systems and submitting them to different ageing conditions. This comparative study of fibre degradation applied in different cementitious matrices reveals the real compatibility of lignocellulosic fibres and Mg-based cements. Sisal fibres, even after accelerated ageing, do neither suffer a significant reduction in cellulose content nor in cellulose crystallinity and crystallite size, when exposed to MgO-SiO2 cement. Fibre integrity is preserved and no deposition of cement phases is produced in MgO-SiO2 environment.Um cimento de baixa alcalinidade à base de blendas de MgO e SiO2 é analisado para o desenvolvimento de Compósitos Cimentícios Reforçados com Fibras (CCRF) celulósicas sem clínquer para resolver os problemas de durabilidade de este tipo de fibras quando são usadas em CCRF com cimento Portland. A evolução da hidratação, desde 7 aos 28 dias, das diferentes formulações é avaliada. Os principais produtos hidratados são o Mg(OH)2 e o gel M-S-H para todas as formulações independentemente da idade estudada. As pastas endurecidas apresentam valores de pH < 11 e bom desempenho mecânico comparado com o cimento Portland convencional. O sistema 60% MgO-40% SiO2 é escolhido como a formulação ótima para o desenvolvimento de CCRF já que é a mais resistente e menos alcalina comparada com 70% MgO-30% SiO2. CCRF com cimento à base de óxido de magnésio e sílica (MgO-SiO2) e fibras celulósicas são produzidos para a análise da durabilidade das fibras lignocelulósicas em ambientes com valores de pH mais baixos comparados com o cimento Portland (PC). O desempenho mecânico a flexão e os ensaios físicos (porosidade aparente, densidade aparente e absorção de água) são comparados aos 28 dias e após de 200 ciclos de envelhecimento acelerado. O cimento à base de MgO-SiO2 preserva a integridade das fibras após o envelhecimento. Os compósitos produzidos com este cimento exibem melhores propriedades após 200 ciclos de envelhecimento acelerado que os compósitos produzidos com cimento Portland. Ambientes com alta concentração de CO2 são avaliados como tratamento de cura para otimizar as matrizes MgO- SiO2 nos CCRF. As amostras são curadas sob 2 condições diferençadas: 1) cura com vapor de água a 55oC e 2) cura com alta concentração de CO2 (20% do volume). As amostras carbonatadas apresentam teores reduzidos de Mg(OH)2 enquanto é produzida uma nova fase cristalina: hidromagnesita [Mg5 (CO3)4⋅(OH) 2⋅4H2O]. Após a carbonatação, o conteúdo de gel M-S-H é reduzido também, indicando uma carbonatação desta fase. A carbonatação aumenta a rigidez da matriz o que influi positivamente no desempenho mecânico e as propriedades físicas dos compósitos sem efeitos prejudiciais ao longo prazo. A adição de sepiolita em CCRF é estudada como possível adição na composição da matriz aglomerante. Baixos teores (1 e 2% em massa) de cimento são substituídos por sepiolita para o estudo das pastas de cimento hidratado e, posteriormente, dos compósitos. O Módulo Elástico Dinâmico das pastas é incrementado com o tempo pela adição de sepiolita. Os ensaios a flexão demostram que a adição de sepiolita melhora a homogeneidade dos compósitos. Reportam-se os efeitos das fibras de sisal após da exposição a sistemas MgO-SiO2 e PC e submetidas a diferentes condições de envelhecimento. Este estudo comparativo da degradação das fibras expostas a diferentes matrizes cimentícias mostra a compatibilidade das fibras lignocelulósicas com os cimentos à base de Mg. As fibras de sisal, inclusive após o envelhecimento acelerado, não apresentam nem redução significativa no conteúdo de celulose nem na cristalinidade da celulose assim como do tamanho de cristalito, quando expostas a cimentos MgO-SiO2

Propiedades de composites de fibra vegetal con matriz cementante de baja alcalinidad

Mármol De Los Dolores, G. (2011). Propiedades de composites de fibra vegetal con matriz cementante de baja alcalinidad. http://hdl.handle.net/10251/15786Archivo delegad

Ternary blended cementitious matrix for vegetable fiber reinforced composites

[EN] The present work analyses the behaviour of different binder matrices in order to implement the addition of paper pulp as reinforcement for cementitious composites and assesses the composites flexural properties with time. To prevent microfibers degradation in high-alkaline environments, lower alkaline matrices may be developed. In the present study ternary binder matrices containing ordinary Portland cement (OPC), gypsum (G) and fluid catalytic cracking catalyst residue (FC3R) are presented for that purpose. To assess the performance of the alternatives matrices, pH and conductivity evolution with time were monitored. Also flexural tests were carried out with the intention of evaluate the efficiency of the matrix to preserve fibres within the composite. According to pH and conductivity results is proved that this ternary system offers lower values at early stages (at 3 days) when compared to OPC systems. This inferior alkalinity might be associated to the better mechanical performance with time of the composites when the ternary matrix is used. After 10 months ageing, all the mechanical properties were higher when compared to composites using OPC. Particularly remarkable is the preservation after ageing of the specific energy and deflection at the modulus of rupture when the low-alkalinity matrices were employed, on the contrary what occurred with samples containing OPC where specific energy and deflection were nearly disappeared.Savastano Junior, H.; Mármol De Los Dolores, G.; Bonilla Salvador, MM.; Borrachero Rosado, MV.; Monzó Balbuena, JM.; Soriano Martinez, L.; Paya Bernabeu, JJ. (2016). Ternary blended cementitious matrix for vegetable fiber reinforced composites. Key Engineering Materials. 668:3-10. doi:10.4028/www.scientific.net/KEM.668.3S310668Fonseca AS, Mori FA, Tonoli GHD, Savastano Junior H, Ferrari DL, Miranda IPA. Properties of an Amazonian vegetable fiber as a potential reinforcing material. Ind Crops Prod 2013; 47: 43–50. doi: 10. 1016/j. indcrop. 2013. 02. 033.Tonoli GHD, Belgacem MN, Bras J, Pereira-da-Silva MA, Rocco Lahr FA, Savastano H. Impact of bleaching pine fibre on the fibre/cement interface. J Mater Sci 2012; 47: 4167–77. doi: 10. 1007/s10853-012-6271-z.Tan T, Santos SF, Savastano H, Soboyejo WO. Fracture and resistance-curve behavior in hybrid natural fiber and polypropylene fiber reinforced composites. J Mater Sci 2012; 47: 2864–74. doi: 10. 1007/s10853-011-6116-1.Jarabo R, Fuente E, Monte MC, Savastano Jr. H, Mutjé P, Negro C. Use of cellulose fibers from hemp core in fiber-cement production. Effect on flocculation, retention, drainage and product properties. Ind Crops Prod 2012; 39: 89–96. doi: 10. 1016/j. indcrop. 2012. 02. 017.Mohr BJ, Nanko H, Kurtis KE. Durability of kraft pulp fiber–cement composites to wet/dry cycling. Cem Concr Compos 2005; 27: 435–48. doi: 10. 1016/j. cemconcomp. 2004. 07. 006.Mohr BJ, Biernacki JJ, Kurtis KE. Microstructural and chemical effects of wet/dry cycling on pulp fiber–cement composites. Cem Concr Res 2006; 36: 1240–51. doi: 10. 1016/j. cemconres. 2006. 03. 020.Santos SF, Rodrigues JA, Tonoli GHD, Almeida AEFS, Savastano Jr. H. Potential Use of Colloidal Silica in Cement Based Composites: Evaluation of the Mechanical Properties. Key Eng Mater 2012; 517: 382–91. doi: 10. 4028/www. scientific. net/KEM. 517. 382.Melo Filho J de A, Silva F de A, Toledo Filho RD. Degradation kinetics and aging mechanisms on sisal fiber cement composite systems. Cem Concr Compos 2013; 40: 30–9. doi: 10. 1016/j. cemconcomp. 2013. 04. 003.Pereira CL, Savastano Jr. H, Payá J, Santos SF, Borrachero MV, Monzó J, et al. Use of highly reactive rice husk ash in the production of cement matrix reinforced with green coconut fiber. Ind Crops Prod 2013; 49: 88–96. doi: 10. 1016/j. indcrop. 2013. 04. 038.Khorami M, Ganjian E. The effect of limestone powder, silica fume and fibre content on flexural behaviour of cement composite reinforced by waste Kraft pulp. Constr Build Mater 2013; 46: 142–9. doi: 10. 1016/j. conbuildmat. 2013. 03. 099.Erdoğan ST, Sağlık AÜ. Early-age activation of cement pastes and mortars containing ground perlite as a pozzolan. Cem Concr Compos 2013; 38: 29–39. doi: 10. 1016/j. cemconcomp. 2013. 03. 004.Senhadji Y, Escadeillas G, Mouli M, Khelafi H, Benosman. Influence of natural pozzolan, silica fume and limestone fine on strength, acid resistance and microstructure of mortar. Powder Technol 2014; 254: 314–23. doi: 10. 1016/j. powtec. 2014. 01. 046.Payá J, Monzó J, Borrachero M. Physical, chemical and mechanical properties of fluid catalytic cracking catalyst residue (FC3R) blended cements. Cem Concr Res 2001; 31: 57–61. doi: 10. 1016/S0008-8846(00)00432-4.Payá J, Monzó J, Borrachero M. Fluid catalytic cracking catalyst residue (FC3R): An excellent mineral by-product for improving early-strength development of cement mixtures. Cem Concr Res 1999; 29: 1773–9. doi: 10. 1016/S0008-8846(99)00164-7.Anthony JW, Bideaux RA, Bladh KW, Nichols MC. Handbook of Mineralogy. Chantilly, Virginia, USA: Mineralogical Society of America; (2001).Colak A. The long-term durability performance of gypsum–Portland cement–natural pozzolan blends. Cem Concr Res 2002; 32: 109–15. doi: 10. 1016/S0008-8846(01)00637-8.Çolak A. Physical, mechanical, and durability properties of gypsum–Portland cement–natural pozzolan blends. Can J Civ Eng 2001; 28: 375–82. doi: 10. 1139/cjce-28-3-375.BS EN 13279-1. Building gypsum and gypsum-based binders for construction. London, England: The British Standards Institution; (2008).Savastano Jr. H, Warden P., Coutts RS. Brazilian waste fibres as reinforcement for cement-based composites. Cem Concr Compos 2000; 22: 379–84. doi: 10. 1016/S0958-9465(00)00034-2.Mármol G, Santos SF, Savastano Jr. H, Borrachero MV, Monzó J, Payá J. Mechanical and physical performance of low alkalinity cementitious composites reinforced with recycled cellulosic fibres pulp from cement kraft bags. Ind Crops Prod 2013; 49: 422–7. doi: 10. 1016/j. indcrop. 2013. 04. 051.Lea FM, Hewlett PC. Lea's chemistry of cement and concrete (2004).Al-Barrak K, Rowell DL. The solubility of gypsum in calcareous soils. Geoderma 2006; 136: 830–7. doi: 10. 1016/j. geoderma. 2006. 06. 011.Soriano L, Monzó J, Bonilla M, Tashima MM, Payá J, Borrachero MV. Effect of pozzolans on the hydration process of Portland cement cured at low temperatures. Cem Concr Compos 2013; 42: 41–8. doi: 10. 1016/j. cemconcomp. 2013. 05. 007