Mechanical properties and durability of cementitious composites reinforced by graphene nanoplatelets with different particle size and surface area

2021 ◽  
Author(s):  
Zhangfan Jiang ◽  
Ugur Kilic ◽  
Osman E. Ozbulut
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Surface Area ◽  
Graphene Nanoplatelets ◽  
Cementitious Composites

Effects of Particle Size and Size Distribution on the Mechanical Properties of EPDM/Silica Vulcanizates

2008 ◽  
Vol 47-50 ◽  
pp. 113-116 ◽  
Author(s):  
M.N. Ichazo ◽  
C. Albano ◽  
M. Hernández ◽  
J. González ◽  
A. Carta
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Size Distribution ◽  
Surface Area ◽  
Bimodal Distribution ◽  
Epdm Rubber ◽  
Surface Areas ◽  
Precipitated Silica ◽  
Internal Mixer ◽  
Tear Properties

In this work we present the influence of different particle size (surface areas: 120,150, 200 and 250 m2/g) and size distribution of precipitated silica on the mechanical properties of Ethylene- Propylene-Diene (EPDM) rubber. The vulcanization system employed was efficient. Compounds were prepared using a Banbury internal mixer. Tensile and tear properties of vulcanized blends were determined according to ASTM D412 and ASTM D624 procedures, respectively. Results show an increasing tendency on tensile properties when particle size decreases, due to the better dispersion of the filler and to a greater interaction with the rubber. Increases of up to 500% on tensile strength and 400% on tear strength were observed. However, there was an incoherent behavior for the silica with surface area of 200 m2/g (Si-200), so size distribution of the aggregates was experimentally determined by a microphotography study. Secondary aggregates size distribution was very different for each type of silica. Aggregates for Si-200 presented a bimodal distribution where the greater frequencies correspond to aggregates with surface area higher than the corresponding values for the Si-120. This fact could explain why the mechanical properties of the EPDM filled with Si-200 are not in between the values of the compounds filled with Si-150 and Si-250.

Influence and Mechanism Analysis of Particle Size Distribution of Multi-System Mineral Admixture on Concrete Performance

2021 ◽  
Vol 1036 ◽  
pp. 386-394
Author(s):  
Fu Xing Cheng ◽  
Yong Liu ◽  
Ji Xiao ◽  
Xiao Xu Deng ◽  
Hai Long Wang
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Specific Surface ◽  
Mechanical Activation ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mineral Admixture ◽  
Mechanism Analysis

To explore the effect of mechanical activation on the particle size distribution of the composite admixture a self-designed test jet mill is used. We have studied the effects of different specific surface areas of composite admixtures on the workability, mechanical properties and durability of concrete and combined X-ray diffraction (XRD) with scanning electron microscopy (SEM) to analyze the mechanism of concrete performance improvement. Results showed that, mechanical activation can significantly increase the content of particles below 3 um; appropriate increase in the specific surface area of composite admixture is conducive to improving the performance of concrete; As the specific surface area increases, the hydration activity of the composite admixture increases first and then tends to be stable; during the hydration process, more thin-plate Ca(OH)2 is converted into needle-shaped AFt, which improves the cement-based material and thereby improving the macro mechanical properties and durability.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

scholarly journals Experimental Analysis of the Mechanical Properties and Resistivity of Tectonic Coal Samples with Different Particle Sizes

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Coalbed Methane ◽  
Coal Sample ◽  
Fine Particles ◽  
Particle Sizes ◽  
Tectonic Coal

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.

scholarly journals An Overview on the Rheology, Mechanical Properties, Durability, 3D Printing, and Microstructural Performance of Nanomaterials in Cementitious Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2950
Author(s):  
Hongwei Song ◽  
Xinle Li
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Three Dimensional ◽  
Cementitious Materials ◽  
Research Area ◽  
Cementitious Composites ◽  
Split Tensile Strength ◽  
Contour Crafting ◽  
Wide Range ◽  
Active Research

The most active research area is nanotechnology in cementitious composites, which has a wide range of applications and has achieved popularity over the last three decades. Nanoparticles (NPs) have emerged as possible materials to be used in the field of civil engineering. Previous research has concentrated on evaluating the effect of different NPs in cementitious materials to alter material characteristics. In order to provide a broad understanding of how nanomaterials (NMs) can be used, this paper critically evaluates previous research on the influence of rheology, mechanical properties, durability, 3D printing, and microstructural performance on cementitious materials. The flow properties of fresh cementitious composites can be measured using rheology and slump. Mechanical properties such as compressive, flexural, and split tensile strength reveal hardened properties. The necessary tests for determining a NM’s durability in concrete are shrinkage, pore structure and porosity, and permeability. The advent of modern 3D printing technologies is suitable for structural printing, such as contour crafting and binder jetting. Three-dimensional (3D) printing has opened up new avenues for the building and construction industry to become more digital. Regardless of the material science, a range of problems must be tackled, including developing smart cementitious composites suitable for 3D structural printing. According to the scanning electron microscopy results, the addition of NMs to cementitious materials results in a denser and improved microstructure with more hydration products. This paper provides valuable information and details about the rheology, mechanical properties, durability, 3D printing, and microstructural performance of cementitious materials with NMs and encourages further research.

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