Role of sugarcane bagasse biogenic silica on cellulosic Opuntia dillenii fibre-reinforced epoxy resin biocomposite: mechanical, thermal and laminar shear strength properties

Author(s):  
M. Mohan Prasad ◽  
S. M. Sutharsan ◽  
K. Ganesan ◽  
N. Ramesh Babu ◽  
T. Maridurai
Author(s):  
K. W. Robinson

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.


2021 ◽  
Vol 13 (15) ◽  
pp. 8164
Author(s):  
Brian E. Bautista ◽  
Lessandro E. O. Garciano ◽  
Luis F. Lopez

There are limited published studies related to the mechanical properties of bamboo species in the Philippines. In this study, the shear strength properties of some economically viable bamboo species in the Philippines were properly characterized based on 220 shear test results. The rationales of selecting this mechanical property are the following: (1) Shear strength, parallel to the fiber, has the highest variability among the mechanical properties; and (2) Shear is one of the governing forces on joint connections, and such connections are the points of failure on bamboo structures when subjected to extreme loading conditions. ISO 22157-1 (2017) test protocol for shear was used for all tests. The results showed that Bambusa blumeana has the highest average shear strength, followed by Gigantochloa apus, Dendrocalamus asper, Bambusa philippinensis, and Bambusa vulgaris. However, comparative analysis, using One-way ANOVA, showed that shear strength values among these bamboo species have significant differences statistically. A linear regression model is also established to estimate the shear strength of bamboo from the physical properties. Characteristic shear strength is also determined using ISO 12122-1 (2014) for future design reference.


2021 ◽  
pp. 096739112098651
Author(s):  
Saeedeh Saadatyar ◽  
Mohammad Hosain Beheshty ◽  
Razi Sahraeian

Unidirectional carbon fiber-reinforced epoxy (UCFRE) is suffering from weak transverse mechanical properties and through-thickness properties. The effect of different amount (0.1, 0.3 and 0.5 phr which is proportional to 0.09, 0.27 and 0.46 wt%, respectively) of multiwall carbon nanotube (MWCNT), on transverse tensile properties, flexural strength, fracture toughness in transverse and longitudinal fiber directions, interlaminar shear strength and lap shear strength of UCFRE has been investigated. Dicyandiamide was used as a thermal curing agent of epoxy resin. MWCNT was dispersed in the epoxy resin by ultrasonic instrument and their dispersion state was investigated by scanning electron microscopy (SEM). The curing behavior of epoxy resin and its nanocomposites was assessed by differential scanning calorimetry. Results show that transverse tensile strength, modulus and strain-at-break were increased by 28.5%, 25% and 14%, respectively by adding 0.1 phr of MWCNT. Longitudinal flexural properties of UCFRE was not changed by adding different amount of MWCNT. Although longitudinal flexural strength was increased by 5% by adding 0.1 phr of MWCNT. Fracture toughness in transverse and longitudinal fiber directions was increased by 39% and 9%, respectively at 0.3 phr of MWCNT. Results also show that interlaminar shear strength and lap shear strength were increased at 0.3 phr of MWCNT by 8% and 5%, respectively. These increases in mechanical properties were due to the good adhesion of fibers to the matrix, interlocking and toughening action of MWCNT as revealed by SEM.


2020 ◽  
Vol 5 (1) ◽  
pp. 711-725
Author(s):  
Sutrisno ◽  
Eka Mulya Alamsyah ◽  
Ginanjar Gumilar ◽  
Takashi Tanaka ◽  
Masaaki Yamada

AbstractThe properties of the laminated veneer lumber (LVL) composed of the boiled veneer of Rubberwood (Hevea brasiliensis) using polyvinyl acetate (PVAc) adhesives in various cold-pressing time and various conditioned time with loaded and unloaded were studied. Five-ply LVL was produced by boiling veneer at 100°C for 90 min as pretreatment and cold-pressing time at 12 kgf cm−2 for 1.5, 6, 18, and 24 h then conditioned at 20°C and 65% relative humidity (RH) with loaded (12 kgf cm−2) and unloaded for 7 days as physical treatment. Especially for the delamination test, the specimens were immersed at 70 ± 3°C for 2 h and dried in the oven at 60 ± 3°C for 24 h; then, the specimens were solidified at room temperature (20°C and 65% RH) with loaded (12 kgf cm−2) and unloaded for 7, 10, 12, and 14 days. To determine the performance of LVL, the density, moisture content (MC), delamination, modulus of elasticity (MOE), modulus of rupture (MOR), horizontal shear strength, and formaldehyde emission tests were conducted according to the Japanese Agricultural Standard (JAS 2008) for structural LVL. The MOE and MOR values were significantly influenced by the physical treatment, however, neither to horizontal shear strength nor to formaldehyde emission. The best performance of LVL has resulted from unloaded LVL with cold-pressed time for 18 h; the MOE and MOR values were 9,345.05 ± 141.61 N mm−2 and 80.67 ± 1.77 N mm−2, respectively. The best value of the horizontal shear strength was obtained from the LVL with 18 h cold-pressing time and conditioned with loaded (13.10 ± 1.47 N mm−2) and unloaded (12.23 ± 1.36 N mm−2). The percentage of delamination values decreased with an increase in the cold-pressing time and conditioning time. The lowest value of delamination (19.06%) was obtained from the LVL with 24 h cold-pressing time and conditioned with loaded for 14 days. Except the delamination test, all other properties fulfilled the JAS.


2016 ◽  
Vol 722 ◽  
pp. 343-350 ◽  
Author(s):  
Martin Vyšvařil ◽  
Tomáš Žižlavský ◽  
Patrik Bayer

Considering the requirement of numerous restoration work on historical buildings with dolomitic lime-based mortars, a research of the applicability and suitability of various types of plasters for repairing the historical plasters have been developed. This work presents the applicability of limestone aggregate and limestone fines to dolomitic lime-based mortars. The role of aggregates on the properties of dolomitic lime mortars was examined by comparing pure quartz sand and limestone aggregate and its quantity in the mortar. Limestone aggregate and limestone fines accelerated the carbonation reaction in the mortars, but the positive impact of limestone aggregates to strength properties of mortars was not observed. Mortars with limestone aggregate showed higher total porosity and water absorption than those with quartz aggregate. Similar results was obtained for mortars with limestone fines. It was found that limestone aggregate and limestone fines, used in this work, is not so suitable and applicable to the dolomitic lime-based mortar as to the aerial lime-based mortars.


2003 ◽  
Vol 22 (4) ◽  
pp. 429-437 ◽  
Author(s):  
M.I. Giannotti ◽  
M.J. Galante ◽  
P.A. Oyanguren ◽  
C.I. Vallo

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