scholarly journals Improved Geotechnical Behavior of an Expansive Soil Amended with Tire-Derived Aggregates Having Different Gradations

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 923
Author(s):  
Amin Soltani ◽  
Abbas Taheri ◽  
An Deng ◽  
Brendan C. O’Kelly
Keyword(s):  
Soil Compaction ◽  
Expansive Soil ◽  
Dry Mass ◽  
Absorption Capacity ◽  
Compression Tests ◽  
Secondary Factor ◽  
Tire Derived Aggregate ◽  
Experimental Laboratory ◽  
Monotonically Decrease ◽  
Potential Use

This experimental laboratory study examines the potential use of tire-derived aggregate (TDA) products as an additive to alleviate the inferior geotechnical properties of a subgrade deposit of clay soil with high expansivity. A total of ten mix designs—the unamended soil and nine soil–TDA blends prepared at 5%, 10% and 20% TDA contents (by dry mass) using three different TDA gradations/sizes—were examined. The experiments included standard Proctor compaction, oedometer swell and unconfined compression tests. The TDA materials’ lower specific gravity, hydrophobic character and higher energy absorption capacity compared with the soil solids led to notable reductions in the soil compaction characteristics. The amendment of the soil with TDA resulted in notable decreases in the rate and magnitude of swelling—the observed reductions were in favor of higher TDA contents, with larger TDA particle size being a secondary factor. Further, for any given TDA size, the variations of strength and toughness with respect to TDA content exhibited rise–fall relationships, peaking at 5% TDA and then decreasing for higher TDA contents. The stiffness and ductility parameters, however, were found to monotonically decrease and increase with the TDA content, respectively. Finally, TDA contents of up to 10%, with gradations equivalent to those of medium and coarse sands, were found to reduce the soil’s swelling potential from high to moderate expansivity, while simultaneously improving its strength-related features, and thus can be deemed as optimum mix design choices from a geotechnical perspective.

Quasi-static Compressive Properties and Behavior of Single-cell Miura Origami Column Fabricated by 3D Printed PLA Material

2020 ◽  
Vol 3 (2) ◽  
pp. 66-73
Author(s):  
Farid Triawan ◽  
Geraldy Cahya Denatra ◽  
Djati Wibowo Djamari
Keyword(s):  
Single Cell ◽  
Peak Stress ◽  
Absorption Capacity ◽  
Compression Tests ◽  
Compressive Properties ◽  
Folding Pattern ◽  
Column Structure ◽  
Thin Walled ◽  
And Behavior ◽  
Initial Peak

The study of a thin-walled column structure has gained much attention due to its potential in many engineering applications, such as the crash box of a car. A thin-walled square column usually exhibits high initial peak force, which may become very dangerous to the driver or passenger. To address this issue, introducing some shape patterns, e.g., origami folding pattern, to the column may become a solution. The present work investigates the compressive properties and behavior of a square box column structure which adopts the Miura origami folding pattern. Several test pieces of single-cell Miura origami column with varying folding angle and layer height are fabricated by a 3D printer. The filament is made of Polylactic Acid (PLA), which is a brittle material. Then, compression tests are carried out to understand its compressive mechanical properties and behavior. The results show that introducing a Miura origami pattern to form a thin-walled square column can dramatically lower down the initial peak stress by 96.82% and, at the same time, increase its ductility, which eventually improves the energy absorption capacity by 61.68% despite the brittle fracture behavior.

scholarly journals Investigation of Energy-Absorbing Properties of a Bio-Inspired Structure

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 881
Author(s):  
Adrian Dubicki ◽  
Izabela Zglobicka ◽  
Krzysztof J. Kurzydłowski
Keyword(s):  
Absorption Capacity ◽  
Compression Tests ◽  
Element Analysis ◽  
Lightweight Structures ◽  
New Energy ◽  
Absorbing Material ◽  
Lightweight Structure ◽  
3D Printed ◽  
Deformation Force ◽  
Energy Absorbing

Numerous engineering applications require lightweight structures with excellent absorption capacity. The problem of obtaining such structures may be solved by nature and especially biological structures with such properties. The paper concerns an attempt to develop a new energy-absorbing material using a biomimetic approach. The lightweight structure investigated here is mimicking geometry of diatom shells, which are known to be optimized by nature in terms of the resistance to mechanical loading. The structures mimicking frustule of diatoms, retaining the similarity with the natural shell, were 3D printed and subjected to compression tests. As required, the bio-inspired structure deformed continuously with the increase in deformation force. Finite element analysis (FEA) was carried out to gain insight into the mechanism of damage of the samples mimicking diatoms shells. The experimental results showed a good agreement with the numerical results. The results are discussed in the context of further investigations which need to be conducted as well as possible applications in the energy absorbing structures.

scholarly journals Evaluation of mortar properties obtained through partial substitution of Portland cement by ashes of oil palm empty fruit bunch

Cerâmica ◽  
2019 ◽  
Vol 65 (375) ◽  
pp. 359-365
Author(s):  
V. A. Coelho ◽  
C. C. Guimarães ◽  
G. G. Doutto ◽  
P. P. Pedra
Keyword(s):  
Portland Cement ◽  
Palm Oil ◽  
Edible Oils ◽  
Absorption Capacity ◽  
Partial Substitution ◽  
Empty Fruit Bunch ◽  
Empty Fruit Bunches ◽  
Production And Consumption ◽  
Potential Use ◽  
Proportional Reduction

Abstract Currently, palm oil is a leader in production and consumption among commercial edible oils, with a growing world production that exceeds 66 million tons per year. It is estimated that the generation of residues from the burning of palm oil empty fruit bunches as fuel in the boilers corresponds to 5% in mass of the total of oil extracted. This work evaluated the mechanical properties resulting from the use of the empty fruit bunch ashes as a partial substitute of Portland cement in mortars in different contents in 1:3 and 1:6 mixes. Mortars obtained with the use of ash presented greater deformability, implying greater workability. The results obtained pointed to potential use of the ash as filler in mortars without loss on compressive strength for contents up to 10% in the 1:3 mix and 5% in the 1:6 mix. It was observed an increase in the void index and the water absorption capacity, with a proportional reduction of the flexural strength.

Dynamic Tensile Properties of Magnesium Nanocomposite

2012 ◽  
Vol 706-709 ◽  
pp. 780-785 ◽  
Author(s):  
Y.B. Guo ◽  
V.P.W. Shim ◽  
B. W. F. Tan
Keyword(s):  
Yield Stress ◽  
Strain Curve ◽  
Absorption Capacity ◽  
Tensile Behaviour ◽  
Al Alloy ◽  
Compression Tests ◽  
Energy Absorption Capacity ◽  
Dynamic Tension ◽  
Melt Deposition ◽  
Tension Compression Asymmetry

In this study, a Mg-6wt%Al alloy and its composite containing 0.22vol% Al2O3 nanoparticles are fabricated using a disintegrated melt deposition technique, and samples are subjected to quasi-static and dynamic tension. Compared to quasi-static loading, both materials exhibit significantly higher yield stresses and tensile strengths, much better ductility, and thus a higher energy absorption capacity under dynamic tension. In terms of nanoparticle addition, its influence on the mechanical properties are not notable; enhancement of the elastic modulus, yield stress and tensile strength are negligible, and there is a small reduction in ductility. The tensile behaviour obtained in this investigation was compared with results of previous compression tests, and significant tension-compression asymmetry in the response is observed. The tensile yield stress is noticeably larger than that in compression, and the profile of the stress-strain curve for tension differs from that for compression – it is convex upwards for tension, but concave upwards for compression. A possible reason for this asymmetry is the occurrence of twinning in compression and its absence in tension.

scholarly journals ASSESSMENT OF LEGUMES WITH POTENTIAL USE AS GREEN MANURE IN THE COASTAL TABLELANDS OF PIAUÍ STATE, BRAZIL

2018 ◽  
Vol 31 (3) ◽  
pp. 584-592 ◽  
Author(s):  
MAURO SERGIO TEODORO ◽  
KARINA NEOOB DE CARVALHO CASTRO ◽  
JOÃO AVELAR MAGALHÃES
Keyword(s):  
Green Manure ◽  
Dry Mass ◽  
Fresh Mass ◽  
Legume Species ◽  
Randomized Design ◽  
Assessment Period ◽  
Soil Sustainability ◽  
Phenological Cycle ◽  
Brazilian Northeast ◽  
Potential Use

ABSTRACT Green manure may lead to physical, chemical, and biological improvements to the soil. However, the information on its use in the Brazilian Northeast is scarce. The aim of this study was to assess the phenological cycle and phytomass productivity of seven legume species. This study was conducted in the second semester of 2015 in a completely randomized design with seven treatments and four replications. Plant height, fresh mass of shoot (FMS), dry mass of shoot (DMS), fresh mass of root (FMR), and dry mass of root (DMR) were determined at 100 days after sowing. Germination, flowering, and pod maturation were also assessed. The highest averages of FMS were observed in Crotalaria breviflora and Crotalaria mucronata, followed by Canavalia ensiformis, whereas the highest averages of DMS were observed in C. breviflora, C. ensiformis, C. mucronata, and Cajanus cajan cv. IAPAR 43. The highest averages of FMR were obtained by C. breviflora and C. mucronata, followed by C. cajan cv. Fava Larga. The species C. mucronata, C. cajan cv. IAPAR 43, and C. breviflora presented the highest averages of DMR. In addition, C. juncea, C. ensiformis, and C. cajan cv. IAPAR 43 were the earlier species regarding flowering, while C. cajan cv. Fava Larga was the later species. C. juncea was the earliest among all studied species regarding pod maturation. The tested legume species obtained promising initial results during the assessment period, being able to meet the expectations of biomass production and contributing to soil sustainability in this region.

scholarly journals Potential use of ash from sugarcane bagasse to produce passion fruit seedlings

2020 ◽  
pp. 408-414
Author(s):  
Henrique Guimarães de Favare ◽  
Sandra da Costa Preisigke ◽  
Leonarda Grillo Neves ◽  
Kelly Lana Araújo ◽  
Milson Evaldo Serafim ◽  
...  
Keyword(s):  
Sugarcane Bagasse ◽  
Soil Structure ◽  
Block Design ◽  
Dry Mass ◽  
Passion Fruit ◽  
Randomized Block Design ◽  
The Family ◽  
Set Up ◽  
Physical And Chemical ◽  
Potential Use

The production of good quality passion fruit seedlings depends on substrates with adequate physical and chemical characteristics. Therefore, this experiment was conducted to evaluate the effect of doses of ash from burning of sugarcane bagasse on improvement of traits of the substrate "gully soil". The experiment was set up in a greenhouse and arranged in randomized block design, in a 2x7x2 factorial scheme. The following factors and their respective levels were studied: (i) soil structure,- aggregating between 4 and 10 mm and <2 mm; (ii) ash doses - 0; 1.5; 3; 6; 12; 24; and 48 t ha-1; (iii) families of passion fruit - F29 and F48. The use of ash combined to the soil with structure <2mm significantly increased the production of shoot fresh mass and shoot dry mass for both families studied. The density of the substrate obtained by the mixture of ash and gully soil (soil) decreased as ash doses increased, regardless of the size of the aggregates and the family studied.

scholarly journals Soil compaction during harvest operations in five tropical soils with different textures under eucalyptus forests

2018 ◽  
Vol 42 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Paula Cristina Caruana Martins ◽  
Moacir de Souza Dias Junior ◽  
Ayodele Ebenezer Ajayi ◽  
Ernesto Norio Takahashi ◽  
Diego Tassinari
Keyword(s):  
Bearing Capacity ◽  
Soil Compaction ◽  
Sandy Loam ◽  
Traffic Intensity ◽  
Compression Tests ◽  
Load Bearing Capacity ◽  
Undisturbed Soil ◽  
Load Bearing ◽  
Structure Degradation ◽  
Precompression Stress

ABSTRACT Traffic of farm machinery during harvest and logging operations has been identified as the main source of soil structure degradation in forestry activity. Soil susceptibility to compaction and the amount of compaction caused by each forest harvest operation differs according to a number of factors (such as soil strength, soil texture, kind of equipment, traffic intensity, among many others), what requires the adequate assessment of soil compaction under different traffic conditions. The objectives of this study were to determine the susceptibility to compaction of five soil classes with different textures under eucalyptus forests based on their load bearing capacity models; and to determine, from these models and the precompression stresses obtained after harvest operations, the effect of traffic intensity with different equipment in the occurrence of soil compaction. Undisturbed soil samples were collected before and after harvest operations, being then subjected to uniaxial compression tests to determine their precompression stress. The coarse-textured soils were less resistant and endured greater soil compaction. In the clayey LVd2, traffic intensity below four Forwarder passes limited compaction to a third of the samples, whereas in the sandy loam PVd all samples from the 0-3 cm layer were compacted regardless of traffic intensity. The Feller Buncher and the Clambunk presented a high potential to cause soil compaction even with only one or two passes. The use of soil load bearing capacity models and precompression stress determined after harvest and logging operations allowed insight into the soil compaction process in forestry soils.

scholarly journals Correction of soil compaction using wood ash in safflower crop

2019 ◽  
pp. 1375-1382
Author(s):  
Tulio Martinez Santos ◽  
Edna Maria Bonfim Silva ◽  
Tonny José Araújo da Silva ◽  
Ana Paula Alves Barreto Damasceno
Keyword(s):  
Bulk Density ◽  
Root System ◽  
Soil Compaction ◽  
System Development ◽  
Block Design ◽  
Dry Mass ◽  
Wood Ash ◽  
Experimental Unit ◽  
Root System Development ◽  
Randomized Block Design

Soil compaction is a big limitation to food production in agriculture. Wood ash is an agro-industrial residue generated by the burning of biomass in boilers for energy production. It can be used as a corrective agent and fertilizer of the soil. In this context, the objective of this study was to evaluate the root system of safflower cultivated under bulk density levels and wood ash doses in dystrophic Oxisol. The experiment was conducted in a greenhouse with a randomized block design under a 5x5 factorial scheme composed of 5 wood ash doses (0, 8, 16, 24, 32 g dm-3) and 5 bulk density levels (1.0, 1.2, 1.4, 1.6, 1.8 Mg m-3) with 4 replicates. The soil was collected from 0-0.20 m depth layer. Later it was incubated with the respective wood ash doses. Each experimental unit consisted of a pot made of three PVC (polyvinyl chloride) rings, in which the layers of 0.1-0.2 m were compacted. At 75 days after emergence, the plants were cut, their roots washed and the volume and dry mass checked. The results were submitted to analysis of variance and subsequent regression test, both at 5% probability. Soil densities negatively influenced the root system development and culture of safflower. Application of wood ash doses of 20 to 24 g dm-3 significantly improved root development of plant.

CONTRIBUIÇÃO DE BIOESTIMULANTES CONTENDO MICRORGANISMOS RIZOSFÉRICOS NA ABSORÇÃO DE FÓSFORO PELO MILHO

2017 ◽  
Vol 15 (3) ◽  
pp. 572
Author(s):  
RAFAEL UMBELINO BENTO ◽  
ADILSON PÉLA ◽  
MATHEUS DE ARAÚJO RIBEIRO ◽  
JOÃO ANTÔNIO GONÇALVES E SILVA ◽  
SIHELIO JULIO SILVA CRUZ
Keyword(s):  
Zea Mays ◽  
Phosphate Fertilizer ◽  
Dry Mass ◽  
Phosphate Fertilizers ◽  
Rhizosphere Microorganisms ◽  
Phosphorus Absorption ◽  
P Content ◽  
Potential Use ◽  
Ear Number ◽  
Corn Grains

RESUMO - Este trabalho teve como objetivo avaliar o potencial uso de microrganismos rizosféricos em funçãode diferentes doses de fosfato aplicadas na adubação de semeadura da cultura do milho no campo experimental daUniversidade Estadual de Goiás / Campus Ipameri. O delineamento experimental utilizado foi blocos casualizados,em esquema fatorial 5 x 2 com quatro repetições. Foram dez tratamentos, sendo cinco doses de P2O5 na adubaçãode semeadura (0, 20, 40, 80 e 160 kg de P2O5 ha-1) e dois tratamentos constituídos pela presença ou pela ausência daaplicação do biofertilizante (BACSOL® + ORGASOL®), contendo estirpes de bactérias e fungos rizosféricos. Porocasião da colheita, foram realizadas as avaliações de matéria seca de planta, de matéria seca de espiga, de número defileiras de grãos por espiga, de massa de 100 grãos, de teores de P na planta e nos grãos. Ocorreu efeito de doses emfunção da inoculação. Os benefícios da inoculação com microrganismos promotores de crescimento na massa secada parte aérea, nos teores de P na planta e nos grãos do milho se manifestaram principalmente em condições de baixadisponibilidade, ou seja, nas menores doses de fósforo.Palavras-chave: Zea mays, adubação fosfatada, disponibilização de formas inorgânicas de fosfato, Cerrado.MICRO P-SOLUBILIZING CONTRIBUTION IN PHOSPHORUS ABSORPTION BY MAIZEABSTRACT – This study aimed to evaluate the potential use of rhizosphere microorganisms due to different dosesof phosphate fertilizer applied at sowing of corn in the experimental field of the Universidade Estadual de Goiás/UnitIpameri. The experimental design was randomized blocks in a 5x2 factorial scheme with four replications. The total often treatments comprised five levels of P2O5 at sowing fertilization (0, 20, 40, 80 and 160 kg P2O5 ha-1) in the presenceor absence of the application of biofertilizers (BACSOL® + ORGASOL®) containing strains of rhizosphere bacteriaand fungi. Plant dry matter ear, number of kernel rows per ear, weight of 100 grains, P content in plant and grainswere evaluated at harvest. Effect of doses depending on the inoculation was observed. The benefits of inoculation withgrowth-promoting microorganisms in the dry mass of the aerial part, the P content in plant and corn grains occurredmainly in low availability conditions, ie in the lower phosphorus levels.Keywords: Zea mays, phosphate fertilizers, availability of inorganic forms of phosphates, Cerrado.

Methods for Filling Hollow Structures with Aluminium Foam

2010 ◽  
Vol 638-642 ◽  
pp. 61-66 ◽  
Author(s):  
Joachim Baumeister
Keyword(s):  
Energy Absorption ◽  
Hybrid Structure ◽  
Absorption Capacity ◽  
Aluminium Foam ◽  
Compression Tests ◽  
Foaming Agent ◽  
Hollow Structures ◽  
Industrial Sectors ◽  
Foam Filling ◽  
Application Potential

Aluminium foams produced according to the powder metallurgical/foaming agent process are currently being used in several industrial sectors, such as automotive, rail transport or machine tools. Nevertheless there still is a high further application potential to be exploited. Especially in hybrid structures, e.g. in automotive structures that are locally filled with aluminium foam, great improvements regarding the energy absorption capacity and the sound absorption behaviour can be obtained. In the present paper several methods that allow for filling or local filling of hollow structures are investigated and presented. The effect of the foam filling on the energy absorption behaviour of the hybrid structure is discussed. Similar effects were also observed in compression tests on foam filled hollow profiles. The results of these investigations are presented.

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