Thermal and mechanical characteristics of cement nanocomposites

2013 ◽  
Vol 20 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Mostafa Jalal ◽  
Esmaeel Mansouri
Keyword(s):  
Mechanical Properties ◽  
Thermogravimetric Analysis ◽  
Mechanical Characteristics ◽  
The Self ◽  
Cementitious Composites ◽  
Strength Development ◽  
Thermal And Mechanical Properties ◽  
Conduction Calorimetry ◽  
Different Types ◽  
Flexural Tests

AbstractWidespread applications and advantages of different types of composite materials have drawn researchers’ attention toward the science and technology of composites. Among these materials, cementitious composites have a special place, as they have many applications in various fields of structural and civil engineering. Due to the importance of cementitious composites and their behavior, investigation of their properties is of great importance. Thus in the present study, thermal and mechanical properties of the self-compacting cementitious composites containing different fractions of nano TiO2 have been investigated. Mechanical properties were assessed through compressive, split tensile and flexural tests. The thermal properties were assessed through thermogravimetric analysis (TGA) and conduction calorimetry tests. Accelerated peak appearance in conduction calorimetry tests and more weight loss in thermogravimetric analysis could indicate that TiO2 nanoparticles could lead to strength development at earlier ages and improve the properties of the self-compacting cementitious composites.

Mechanical Properties of Modified Engineered Cementitious Composites (MECC) Incorporating Marble Dust

2021 ◽  
Vol 9 (8) ◽  
pp. 1140-1146
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Bottom Surface ◽  
Cementitious Composites ◽  
Strength Development ◽  
Shape Effect ◽  
Main Concern ◽  
Engineered Cementitious Composites ◽  
Flexure Strength ◽  
Marble Dust

Engineered cementitious composites (ECC) are a type of high-performance fiber reinforced cementitious composite. ECC has different applications in the construction field due to its inherent characteristics of high tensile strain. The main concern regarding ECC is its high cost. The content of cement is high contributing to its cost. In this research work, the cement in ECC is replaced with marble dust and its mechanical properties such as compressive strength and flexure strength have been assessed. For this purpose, both cubes and cylinders were tested at different test ages for finding the compressive strength development with time and observe the shape effect of specimens on the compressive strength of ECC mixes. Beam members were tested for finding the flexure strength of ECC mixes. Deflection gauge was also installed at the mid span on the bottom surface of the beams to find the maximum mid span deflection before failure. The compression test results of both cylinders and cubes revealed that using of marble dust has negative effect on the compressive strength of ECC. The flexure strength result showed that marble dust can be used up to some extent replacing cement will increase the flexure strength. The result of mid span deflection suggests that by incorporating marble dust in ECC, its ductility increases.

Effect of Meta- and Para-Substitution of the Aromatic Diamines on the Properties of Poly(Amidoimidourethane)

2016 ◽  
Vol 721 ◽  
pp. 23-27 ◽  
Author(s):  
Ilya Kobykhno ◽  
Oleg Tolochko ◽  
Ekaterina Vasilyeva ◽  
Andrei Didenko ◽  
Danila Kuznetcov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Polymer Structure ◽  
Multiblock Copolymers ◽  
Thermal And Mechanical Properties ◽  
Amino Groups ◽  
Scanning Calorimetry ◽  
Aromatic Diamines

The paper experimentally studies the effect of meta and para- substitution of the amino groups in the diamine used in the synthesis of multiblock copolymers. The way for synthesis of new multiblock copolymers with the possibility of replacing the diamine in the polymer structure was shown. Thermal and mechanical properties of synthesized copolymers had been characterized by means of differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical thermal analysis and by nanoindentation and tensile test.

Self-Locking Origami Structures and Locking-Induced Piecewise Stiffness

2017 ◽  
Author(s):  
Hongbin Fang ◽  
Shih-Cheng A. Chu ◽  
K. W. Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Design Guidelines ◽  
The Self ◽  
Structural Stiffness ◽  
Pattern Design ◽  
Stiffness Characteristics ◽  
Stiffness Profile ◽  
Multiple Cells ◽  
Sudden Jump

The folding motion of an origami structure can be stopped at a non-flat position when two of its facets bind together. Such facet-binding will induce self-locking so that the overall origami structure can stay at a pre-specified configuration without the help of additional locking devices or actuators. This research investigates the designs of self-locking origami structures and the locking-induced kinematical and mechanical properties. We show that incorporating multiple cells of the same type but with different geometry could significantly enrich the self-locking origami pattern design. Meanwhile, it offers remarkable programmability to the kinematical properties of the self-locking origami structures, including the number and position of locking points, and the deformation range. Self-locking will also affect the mechanical characteristics of the origami structures. Experiments and finite element simulations reveal that the structural stiffness will experience a sudden jump with the occurrence of self-locking, inducing a piecewise stiffness profile. The results of this research would provide design guidelines for developing self-locking origami structures and metamaterials with excellent kinematical and stiffness characteristics, with many potential engineering applications.

scholarly journals Experimental Study on Anchorage Performance of Resin Grout with Steel Segment

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Junchao Shen
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Simulation Method ◽  
The Self ◽  
Underground Space ◽  
Anchorage System ◽  
Different Types ◽  
Improvement Effect ◽  
Addition Amount

With the advantages of large anchoring force and fast anchoring speed, resin cartridge has become the main anchoring means of geotechnical engineering and underground space engineering support. Based on the theoretical analysis, it is clear that adding aggregate can improve the mechanical properties of grout and the bolt-grout interface stress state; the mechanical properties of aggregate are positively correlated with its improvement effect on anchorage performance. By using the numerical simulation method, it is concluded that the addition of steel segments into the resin grout can improve the stiffness of the anchorage system and enhance the energy absorption and antifailure ability of the anchorage system. Relying on the self-developed anchorage mixing device, the effects of steel segment diameter and addition amount on the anchoring force were studied experimentally, and the optimal addition amount of different types of steel segment to improve the maximum anchoring force was determined.

Investigation of the Mechanical Properties of Engineered Cementitious Composites with Low Fiber Content and with Crumb Rubber and High Fly Ash Content

2019 ◽  
Vol 2673 (5) ◽  
pp. 418-428 ◽  
Author(s):  
Hassan Noorvand ◽  
Gabriel Arce ◽  
Marwa Hassan ◽  
Tyson Rupnow ◽  
Louay N. Mohammad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fly Ash ◽  
Crumb Rubber ◽  
Ash Content ◽  
Fiber Content ◽  
Cementitious Composites ◽  
Engineered Cementitious Composites ◽  
Different Types ◽  
Strength And Ductility

Engineered cementitious composites (ECCs) are a type of micromechanically-designed cementitious composite reinforced with a moderate volume fraction of short fiber, typically 2% by volume. ECCs form steady-state multiple cracking that considerably improves the tensile strength and ductility of traditional concrete. In this study, the properties of matrix and the interface of ECCs were tailored through the use of crumb rubber, different types of sand, and different replacement levels of cement with fly ash. The study examined the effect of sand replacement with crumb rubber (20% by volume), two types of river sands (coarse and fine), increasing the content of class F fly ash (up to 75% cement replacement), and low fiber content (1.75%) on the mechanical properties of ECCs. Compressive strength, uniaxial tensile, and third-point bending tests were performed to characterize the properties of ECC mixes. Experimental results demonstrated that increasing fly ash content and using crumb rubber favored ductility of the composites. However, higher fly ash contents and a low water-to-binder (W/B) ratio produced lower strengths as these limited the pozzolanic reaction of fly ash making it act partially as a filler. While incorporation of crumb rubber showed adverse effects on the tensile strength of ECC materials (up to 26% decrease), the tensile ductility of ECC materials improved significantly (up to 434% improvement). Moreover, the implementation of different types of sand produced minor effects on the mechanical properties of ECCs. Overall, a tradeoff between the strength and ductility of the composites was detected, which highlights the implications of matrix/interface tailoring in the overall performance of ECC.

Evolution of thermal and mechanical properties of mine tailings and fly ash mixtures during curing period

2014 ◽  
Vol 51 (5) ◽  
pp. 570-582 ◽  
Author(s):  
Joon Kyu Lee ◽  
Julie Q. Shang
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Fly Ash ◽  
Mine Tailings ◽  
Mechanical Characteristics ◽  
Early Stage ◽  
Expansive Soils ◽  
Thermal And Mechanical Properties ◽  
Curing Period ◽  
Compaction Energy

Fly ash is often used as a binder for modifying the properties of geomaterials, such as organic and expansive soils, sludge from water treatment, dredged sediments, mine tailings, etc. Changes in thermal and mechanical properties of compacted mixtures of mine tailings and fly ash are studied over a curing period of 120 h. The study includes the measurement of thermal conductivity, temperature, unconfined compressive strength, and elastic modulus. Effects of the amount of fly ash added to mine tailings, molding water content, and compaction energy on these properties are investigated. Pore-size distribution and surface texture are analyzed to characterize the microstructures of fly ash treated–mine tailings. Relationships between the thermal conductivity and properties that capture packing and mechanical characteristics of mine tailings and fly ash mixtures are established. These observations provide enhanced understanding of thermal, mechanical, and structural properties of fly ash–treated mine tailings, which is associated with the hydration process at the early stage of the mixtures.

scholarly journals Polyimide-Based Nanocomposites with Binary CeO2/Nanocarbon Fillers: Conjointly Enhanced Thermal and Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1952
Author(s):  
Alexandra L. Nikolaeva ◽  
Iosif V. Gofman ◽  
Alexander V. Yakimansky ◽  
Elena M. Ivan’kova ◽  
Ivan V. Abalov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Carbon Nanoparticles ◽  
Mechanical Characteristics ◽  
Functional Performance ◽  
Polymer Materials ◽  
Thermal And Mechanical Properties ◽  
Binary Blends ◽  
Working Temperature ◽  
The Matrix

To design novel polymer materials with optimal properties relevant to industrial usage, it would seem logical to modify polymers with reportedly good functionality, such as polyimides (PIs). We have created a set of PI-based nanocomposites containing binary blends of CeO2 with carbon nanoparticles (nanocones/discs or nanofibres), to improve a number of functional characteristics of the PIs. The prime novelty of this study is in a search for a synergistic effect amidst the nanofiller moieties regarding the thermal and the mechanical properties of PIs. In this paper, we report on the structure, thermal, and mechanical characteristics of the PI-based nanocomposites with binary fillers. We have found that, with a certain composition, the functional performance of a material can be substantially improved. For example, a PI containing SO2-groups in its macrochains not only had its thermal stability enhanced (by ~20 °C, 10% weight loss up to 533 °C) but also had its stiffness increased by more than 10% (Young’s modulus as high as 2.9–3.0 GPa) in comparison with the matrix PI. In the case of a PI with no sulfonic groups, binary fillers increased stiffness of the polymer above its glass transition temperature, thereby widening its working temperature range. The mechanisms of these phenomena are discussed. Thus, this study could contribute to the design of new composite materials with controllable and improved functionality.

Mechanical Behavior of Glued Laminated Pressed Bamboo Guadua Using Different Adhesives and Environmental Conditions

2014 ◽  
Vol 600 ◽  
pp. 57-68 ◽  
Author(s):  
Patricia Luna ◽  
Caori Takeuchi ◽  
Edwar Cordón
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Environmental Conditions ◽  
Urea Formaldehyde ◽  
Experimental Tests ◽  
Mechanical Tests ◽  
Different Types ◽  
Humidity Chamber ◽  
Flexural Tests ◽  
The One

This paper presents the mechanical properties measured on glued laminated pressed guadua samples. Experimental tests like shear parallel to fiber, tensile and shear perpendicular to fiber and flexural tests were carried out using three different types of adhesives: European Melamine Urea Formaldehyde, Colombian Melamine Urea Formaldehyde, and Polivinil Acetate humidity resistant. In order to study the behavior of the material in aggressive environmental conditions, half of the samples used in the mechanical tests were introduced in a temperature and humidity chamber for 45 days set to 45°C of temperature and 95% of relative humidity, usual environmental conditions in Chocó Colombia.The results showed that the highest values of mechanical strength were obtained for samples made with European Melamine Urea Formaldehyde. In addition, it was found that this adhesive was the one with better behavior under the aggressive environmental conditions simulated.

Thermal and Mechanical Characteristics of a HSLA Steel as Joint Partner for Hot Stamping Tailor Welded Boron Steel

2014 ◽  
Vol 1063 ◽  
pp. 104-107
Author(s):  
Bing Tao Tang ◽  
Qiao Ling Wang ◽  
Wei Zheng ◽  
Zheng Jun Yuan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Hsla Steel ◽  
Hot Stamping ◽  
Boron Steel ◽  
Thermal And Mechanical Properties ◽  
Safety Requirements ◽  
Automobile Safety ◽  
Tailor Welded Blanks ◽  
Body Components

In order to further reduce the weight and at the same time guarantee the automobile safety, hot stamping of Tailor-Welded Blanks (TWBs), is developed recently to meet the environmental and safety requirements by supplying car structural body components with functionally optimized and tailored mechanical properties. In the article, an appropriate partner material for the quenchenable boron steel B1500HS based on the phase transformation and deformation behavior under process relevant conditions is determined. Microhardness is measured and metallographic is investigated. It is verified that the B340LA steel is an appropriate joint partner with ideal thermal and mechanical properties.

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