scholarly journals Fabricación de ladrillos con polvo-residuo de mármol en México

2020 ◽  
Author(s):  
Cesar Ponce Palafox ◽  
Julián Carrillo ◽  
Areli López-Montelongo
Keyword(s):  
Management Plan ◽  
Experimental Program ◽  
Compression Tests ◽  
Seismic Demands ◽  
Load Bearing ◽  
Compression Load ◽  
Palabras Clave ◽  
Marble Powder ◽  
The Individual ◽  
Compressive Tests

Resumen La industria del mármol genera gran cantidad de desperdicio en polvo. Estos desechos carecen de un adecuado plan de manejo, además de resultar altamente contaminantes a la población que rodea el lugar de los depósitos de estos materiales. Para ofrecer una solución, en este artículo se presentan los resultados del desarrollo de un ladrillo a base del polvo de mármol. El programa experimental incluye 16 dosificaciones diferentes en las que se varía la cantidad de cemento, cal y arena, y se deja constante el polvo de mármol. El programa incluye el ensayo a compresión de 160 ladrillos, 3 ensayos a compresión en muretes, 3 pruebas de adherencia a compresión en muretes y 48 pruebas de absorción.  Los resultados de compresión y adherencia demostraron que estos ladrillos podrían ser utilizados para la construcción de muros de carga en vivienda desarrolladas en zonas de amenaza sísmica baja. Palabras clave:  Absorción; adherencia; compresión; muros de carga; vivienda   Abstract The marble industry generates large amount of dust waste. These wastes do not have a proper management plan, as well as being highly contaminating the population surrounding the site of the deposits of these materials. To offer a solution, this article shows the results of the development of a brick-based marble powder to achieve sufficient compressive strength to construction masonry walls in low-rise housing. The experimental program includes 16 different dosages that varies the amount of cement, lime, and sand, and keeping constant the marble powder. The program includes the compressive tests for 160 bricks, compressive tests for 3 small walls, validated adherence under compression tests for 3 small walls, and absorption tests for 48 bricks. The results of the test showed that the compression strength of the individual bricks and wall is 4.0 MPa y 1.9 MPa, respectively, and the absorption of the bricks es 21 %. This results of absorption , compression and adhesion are a first indication of the feasibility of used  these bricks for the construction of load-bearing walls in housing developed in areas of low seismic demands. Key Words: Absorption; adhesion; compression; load-bearing walls; housing

scholarly journals Analysis and validation of correlation curves between sclerometry and compression tests for the evaluation of compressive strength of concretes

2018 ◽  
Vol 11 (4) ◽  
pp. 779-809
Author(s):  
T. M. OLIVEIRA ◽  
M. C. R. FARAGE ◽  
L. GOLIATT ◽  
T. C. BITTENCOURT
Keyword(s):  
Compressive Strength ◽  
Experimental Program ◽  
Construction Site ◽  
Structural Elements ◽  
Compression Tests ◽  
Concrete Compressive Strength ◽  
Equipment Manufacturer ◽  
Cylindrical Samples ◽  
Compressive Tests

Abstract The present work consists in obtaining correlation curves between compressive tests and sclerometry tests from an extensive experimental program comprising 630 concrete cylindrical samples cast in laboratory, employing materials and methods available in Brazil. The concretes, with compressive strengths ranging from 20~MPa to 50~MPa, were submitted to sclerometry tests and mechanical compressive tests. The results were used to obtain correlation curves. which were adopted in measurements of structural elements molded in a construction site, indicating that the curves provided by the equipment manufacturer are not suitable for the material in study. This is the first stage of a broader study aiming to contribute to the improvement of the Brazilian code regulating the application of the sclerometry to obtain concrete compressive strength.

Experimental and numerical investigations of square concrete-filled double steel tubular stub columns

2021 ◽  
pp. 136943322110041
Author(s):  
Junchang Ci ◽  
Mizan Ahmed ◽  
Hong Jia ◽  
Shicai Chen ◽  
Daxing Zhou ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Concrete Strength ◽  
Experimental Program ◽  
Compression Tests ◽  
Compression Load ◽  
Short Columns ◽  
Test Parameters ◽  
Wide Range ◽  
Axial Behavior ◽  
Stub Columns

In this paper, the structural behavior of concrete-filled double steel tubular (CFDST) stub columns composed of square hollow sections is investigated experimentally and numerically. The experimental program comprises compression tests on short columns loaded concentrically. The test parameters mainly focused on the influences of the width-to-thickness ratios of steel tubes and concrete strength on the axial behavior of CFDST stub columns. Finite element (FE) models are also developed to investigate the influences of a wide range of structural parameters on their axial performance. It is observed that square CFDST columns have improved strength and ductility compared to their CFST and DCFST counterparts. Finally, a calculation formula is proposed to predict their ultimate compressive strengths under the axial compression load.

scholarly journals Hygrothermal Ageing Influence on BVI-Damaged Carbon/Epoxy Coupons under Compression Load

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2038
Author(s):  
Maria Pia Falaschetti ◽  
Matteo Scafé ◽  
Nicola Zavatta ◽  
Enrico Troiani
Keyword(s):  
Residual Strength ◽  
Impact Damage ◽  
Mechanical Analysis ◽  
Test Method ◽  
Combined Loading ◽  
Compression Load ◽  
Impact Location ◽  
Hygrothermal Ageing ◽  
Influence Of Water ◽  
Compressive Tests

Composite materials usage in several industrial fields is now widespread, and this leads to the necessity of overcoming issues that are still currently open. In the aeronautic industry, this is especially true for Barely Visible Impact Damage (BVID) and humidity uptake issues. BVID is the most insidious kind of impact damage, being rather common and not easily detectable. These, along with the ageing that a composite structure could face during its operative life, could be a cause of fatal failures. In this paper, the influence of water absorption on impacted specimens compressive residual strength was studied. Specimens were impacted using a modified Charpy pendulum. Two different locations were chosen for comparison: Near-Edge (NE) and Central (CI). Accelerated hygrothermal ageing was conducted on impacted and reference nonimpacted coupons, placing them in a water-filled jar at 70 °C. Compressive tests were performed in accordance with the Combined Loading Compression (CLC) test method. A Dynamic Mechanical Analysis (DMA) was performed as well. The results showed the influence of hygrothermal ageing, as expected. Nevertheless, the influence of impact location on compressive residual strength is not clearly noticeable in aged specimens, leading to the conclusion that hygrothermal ageing may have a greater effect on composite compressive strength than the analysed BVI damage.

scholarly journals Load Distribution on PET-G 3D Prints of Honeycomb Cellular Structures under Compression Load

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1983
Author(s):  
Olimpia Basurto-Vázquez ◽  
Elvia P. Sánchez-Rodríguez ◽  
Graham J. McShane ◽  
Dora I. Medina
Keyword(s):  
Fused Deposition Modeling ◽  
Structural Characteristics ◽  
Honeycomb Structure ◽  
Cellular Structures ◽  
Displacement Curve ◽  
Compression Tests ◽  
Compression Load ◽  
Fused Deposition ◽  
3D Printed ◽  
Printing Direction

Energy resulting from an impact is manifested through unwanted damage to objects or persons. New materials made of cellular structures have enhanced energy absorption (EA) capabilities. The hexagonal honeycomb is widely known for its space-filling capacity, structural stability, and high EA potential. Additive manufacturing (AM) technologies have been effectively useful in a vast range of applications. The evolution of these technologies has been studied continuously, with a focus on improving the mechanical and structural characteristics of three-dimensional (3D)-printed models to create complex quality parts that satisfy design and mechanical requirements. In this study, 3D honeycomb structures of novel material polyethylene terephthalate glycol (PET-G) were fabricated by the fused deposition modeling (FDM) method with different infill density values (30%, 70%, and 100%) and printing orientations (edge, flat, and upright). The effectiveness for EA of the design and the effect of the process parameters of infill density and layer printing orientation were investigated by performing in-plane compression tests, and the set of parameters that produced superior results for better EA was determined by analyzing the area under the curve and the welding between the filament layers in the printed object via FDM. The results showed that the printing parameters implemented in this study considerably affected the mechanical properties of the 3D-printed PET-G honeycomb structure. The structure with the upright printing direction and 100% infill density exhibited an extension to delamination and fragmentation, thus, a desirable performance with a long plateau region in the load–displacement curve and major absorption of energy.

Measurement of the Material State Including the Effects of Recovery and Recrystallization

2000 ◽  
Author(s):  
M. E. Bange ◽  
A. J. Beaudoin ◽  
M. G. Stout ◽  
S. R. MacEwen
Keyword(s):  
Elevated Temperatures ◽  
High Strain ◽  
Quantitative Measure ◽  
Experimental Program ◽  
Strain Rates ◽  
Compression Tests ◽  
State Variable ◽  
Mechanical Threshold ◽  
Material State

Abstract Deformation at elevated temperatures in combination with high strain rates leads to recovery and recrystallization in aluminum alloys. Previous work in recrystallization has emphasized the detailing of microstructural trend in progression from the deformed to the annealed state. In the following, we examine the effect of rate dependence on deformation on AA 5182 and AA 6061. It is demonstrated that identification of underlying microstructural mechanisms is critical. An experimental program is then outlined for characterization of recovery and recrystallization of AA 5182. Instantaneous hardening rate and flow stress are developed from interrupted compression tests. These data are used to establish a quantitative measure of recovery through evaluation of a state variable for work hardening, the mechanical threshold. It is intended that the results serve as a foundation for development of relations for evolution of a mechanical state variable in the presence of recrystallization. Such a framework is necessary for the practical prediction of interstand recrystallization in hot rolling operations.

scholarly journals Capí­tulo Segundo: Mundo Reo.

Xihmai ◽  
2013 ◽  
Vol 5 (10) ◽  
Author(s):  
Jesús Ignacio Panedas Galindo
Keyword(s):  
Key Words ◽  
Future Generations ◽  
Human Race ◽  
End Of History ◽  
Palabras Clave ◽  
The Future ◽  
The End Of History ◽  
The Individual

Resumen Cuando se empezaron a conocer los testimonios de los supervivientes de los campos de exterminio nazis, la humanidad se consternó. El sufrimiento provocado y la aplicación sistemática y consciente de la técnica a la destrucción de la persona, fueron descubrimientos que pusieron en alerta al hombre sobre la naturaleza del hombre mismo.   Tanto fue el horror que se alcanzó a entrever a través de las narraciones que el  tiempo  se  congeló.  El  reclamo  silencioso  de  las  auténticas  ví­ctimas, quienes murieron, se suspendió en el aire de la memoria hasta que los responsables reconocieran sus culpas. El olvido no podí­a abrazar tan profundos crí­menes.   Por este motivo no puede realizarse el fin de la historia. Los sufrimientos del hombre provocados hasta este grado por el mismo hombre fuerzan un pendiente que ya no puede borrarse. El grito de dolor recuerda a las generaciones futuras la necesidad de una reparación, del perdón, del reconocimiento.   Palabras Clave: Testimonio, memoria, campos de exterminio, fenomenologí­a, hermenéutica, sufrimiento, herencia.   Abstract When testimony from the survivors from Nazi extermination fields were first known, the human race filled with dismay. The suffering provoked and the systematic conscious application of the technique of destruction of the individual, were discoveries that alerted the individual on the nature of the individual itself.   Such a horror was seen through the narrations that time froze.     The silent demand from the authentic victims, who died, was suspended on the air of memory until the responsible recognized their  guilt. Obscurity could not hold such deep crimes.   For this reason the end of history cannot be made. The suffering of the individual provoked up to this point by the individual itself, force an unresolved point that cannot be erased.   The scream of pain reminds the future generations the need to repair, forgive and recognize it.   Key words: Testimony, memory, extermination fields, phenomenology, hermeneutics, suffering, inheritance.

Exploring the Phenomenon of Mass Murder in Public Places

2020 ◽  
pp. 122-155
Author(s):  
Selina E. M. Kerr ◽  
Mary Ann Markey
Keyword(s):  
Threat Assessment ◽  
Emergency Situation ◽  
Management Plan ◽  
Careful Consideration ◽  
Mass Murder ◽  
Mass Shootings ◽  
Public Places ◽  
Music Festival ◽  
Mass Shooting ◽  
The Individual

In 2017, fifty-eight individuals attending an outdoor music festival in Las Vegas were shot and killed, whilst hundreds more were injured. In this chapter, the authors explore the phenomenon of mass shootings taking place in entertainment venues or places of worship. These types of venues bring unique challenges in preventing and responding to mass shooting incidents. These authors recommend initiating a threat assessment system or model to assess changes in an individual's behaviors over time. It is of particular importance to evaluate whether the individual has been preparing for an attack. The six case studies reviewed engaged in active preparations beforehand by procuring weapons, writing manifestos and scoping out potential venues to attack. In terms of how to effectively respond to mass shootings in public locations, it is recommended that an emergency management plan with a range of scenarios is devised beforehand. Careful consideration should be given to ways to deal with individuals with special needs and how to communicate with patrons during an emergency situation.

An Analysis on the Occurrence of Noise between Floors in Apartment Housing

2015 ◽  
Vol 749 ◽  
pp. 406-409
Author(s):  
Jae Min Shin ◽  
Yoon Seok Shin
Keyword(s):  
Time Slot ◽  
Management Plan ◽  
Sound Level ◽  
Actual State ◽  
Noise Sources ◽  
Impact Noise ◽  
Airborne Noise ◽  
Standard Value ◽  
Household Members ◽  
The Individual

The purpose of this study is to determine the actual state of noise occurrence in apartment-unit households by utilizing state data to examine individual noise sources and the types of noise between floors. Among the types of noise between Floors, the top four noise sources were conversation and electrical appliance noise in the airborne noise category, and foot-stepping noise and object-dropping noise in the direct impact noise category. The result shows that in three sources (other than foot-stepping noise), the equivalent sound level was found to exceed the standard value in a specific time slot. The frequency of noise occurrence was shown to be highest between 18:00 and 21:00, after household members had come home from work. Therefore, to reduce noise between floors, a management plan should be introduced based on the actual state of the noise occurrence, considering the individual noise source and the time slot during which noise frequently occurs.

Qualification Approach to Unbonded Flexible Pipes With Fibre Reinforced Armour Layer

2004 ◽  
Author(s):  
Jan Rytter
Keyword(s):  
Offshore Structure ◽  
Flexible Pipe ◽  
Load Bearing ◽  
Compression Load ◽  
Metal Parts ◽  
Analysis Tools ◽  
Industry Standards ◽  
Flexible Pipes ◽  
Unbonded Flexible Pipes ◽  
Load And Resistance Factor

The future water depth capabilities for unbonded flexible pipes is being pushed by NKT Flexibles I/S through the development of an innovative flexible pipe structure, taking full advantage of the material characteristics of metallic, polymeric and fibre reinforced materials. The fluid tight liner and possible insulation of this pipe structure are supported by an inner armour, capable of carrying the external hydrostatic pressure, clamp and crushing loads, as well as axial compression load, and an outer armour, consisting of two cross wound layers of carbon/epoxy composites, carrying the internal pressure as well as end cap forces and applied tension. A permeable and radially flexible outer layer protects the composite armour. Combining known and well-proven flexible pipe technologies and new solutions for materials, structure and functionality of the flexible pipe, positions this future product outside the present industry standards for flexible pipes, e.g. API-17J. The analysis tools used for the conventional flexible pipes are validated by NKT according to the API-17J specification. The API-17J describes load cases and corresponding allowable utilization ratios, stated as design criteria. However, this approach is not directly applicable to the composite pipe, where the same analysis tools will be used, but the material in one of the two primary load bearing layers is made of fibre reinforced polymer, a material class not covered by the API allowable utilization factors. The DNV offshore standard DNV-OS-C501 considers any offshore structure in which the load bearing material is a composite. An accompanying Recommended Practice DNV-RP-F202 for composite risers has also been issued, but is not applicable to the composite flexible pipe. The design equations of the DNV standard are formulated in the so-called Load and Resistance Factor Design (LRFD) format, where partial safety factors are applied to the load effects and to the resistance variables that enter the design equations. The DNV standard DNV-OS-C501 covers composite materials and composite metal interfaces of a structure, metal parts should be designed according to other relevant standards. The API standard can therefore be used for the metal parts. One of the challenges in using this combined approach is the different ways loads are defined in the two standards. In short, this will result in a conventional API design check of the inner armour, the polymer layers, and the secondary layers, whereas the composite tensile armour, special intermediate layers and the interfaces will be analyzed with composite specific tools based on the criteria derived from the DNV standard. The qualification procedure is described and exemplified in the following.

Effect of Concrete-Filled in Chord Tubes on Mechanical Behavior of RHS Steel Tube Trusses

2010 ◽  
Vol 163-167 ◽  
pp. 2171-2175 ◽  
Author(s):  
Jun Ping Liu ◽  
Yong Jian Liu ◽  
Jian Yang
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Steel Tube ◽  
Structural Stiffness ◽  
Static Behavior ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Compression Load ◽  
Hollow Section ◽  
Joint Deformation

Based on the experimental results, this paper presents the effects of concrete-filled in chord on the static behavior of rectangular hollow section (RHS) steel tubular trusses, including failure modes, load bearing capacity and structural stiffness. Failure of RHS trusses occurs at joints wether concrete-filled in chord or not, concrete-filled in chord changed the failure mode. Load bearing capacity and stiffness of joints subjected to compression load increased significantly, while it is limited to the tension joints. Concrete-filled in the compression chord tube can increase its stiffness significantly, while tension chord tube, it is not that obvious. Finally, based on the results discussed, failure modes and their formulas of calculating the load bearing capacity are discussed. Meanwhile, two methods, that is, amplified factor method and stiffness discounting method, which calculate the structural displacement when considering the joint deformation effects are presented.

Sign in / Sign up

Export Citation Format

Share Document