scholarly journals Effect of Gravel-sand Ratio on Physico-mechanical, Thermal and Macrostructural Properties of Micro Epoxy Polymer Concrete based on a Mixture of Alluvial-dune Sand

2020 ◽  
Vol 14 (1) ◽  
pp. 247-261
Author(s):  
Zineb Kerrida ◽  
Hichem Berkak ◽  
Zoubir Makhloufi ◽  
Madani Bederina ◽  
Ahmida Ferhat
Keyword(s):  
Thermal Conductivity ◽  
Water Absorption ◽  
Epoxy Resin ◽  
Epoxy Polymer ◽  
Polymer Concrete ◽  
Dune Sand ◽  
Optimal Values ◽  
Compressive And Flexural Strengths ◽  
Mechanical Performances ◽  
Crushed Limestone

Introduction: In the Polymer Concrete (PC) composites, aggregates are the most important constituent, which considerably affect their performance. The purpose of this experimental study is to examine the effect of Gravel-to-Sand (G/S) ratio on the physico-mechanical, thermal and microstructural properties of epoxy micro-polymer concrete made up of local aggregates. Materials & Methods: The Micro Epoxy Polymer Concrete (MEPC) studied consists of epoxy resin as a binder and a mixture of two types of sands (alluvial (0/0.63 mm) and dune (0/4 mm) sands), as well as crushed limestone gravel (3/8 mm). Six compositions were prepared with two epoxy resin contents (10% and 14% of the total weight of mixture) and three G/S ratios (0.25, 0.50 and 0.75). The studied properties are density, water absorption, compressive and flexural strengths, thermal conductivity, thermal diffusivity, specific heat and macrostructure. Results & Discussion: The obtained results show that the G/S ratio, as well as the epoxy resin content, has a significant influence on the properties of MEPC. In addition, 14% epoxy resin and the G/S ratio of 0.75 can be considered as optimal values, which lead to very interesting physico-mechanical performances (denser and less porous material, more resistant with almost similar thermal conductivity). Moreover, the density, the water absorption and the optical microscopic observation confirm that mixes containing 14% epoxy are more impermeable, compact and homogeneous than those containing 10% epoxy. Conclusion: Finally, it should be noted that the incorporation of aggregates being relatively coarse decreases the grains’ specific surface and reduces the porosity of the granular mix, which enable the epoxy product to completely cover the surface of mineral grains. A perfect covering of aggregate grains with a bender improves the adhesion between the aggregates and the polymer matrix.

scholarly journals Micromechanical Modeling of Flexural Strength for Epoxy Polymer Concrete

2017 ◽  
Vol 09 (08) ◽  
pp. 1750117 ◽  
Author(s):  
Dongpeng Ma ◽  
Yiping Liu ◽  
Nanli Zhang ◽  
Zhenyu Jiang ◽  
Liqun Tang ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Epoxy Resin ◽  
Epoxy Polymer ◽  
Resin Content ◽  
Micromechanical Modeling ◽  
Polymer Concrete ◽  
Flexural Performance ◽  
Micromechanics Models ◽  
Strong Adhesion ◽  
Good Agreement

Epoxy polymer concrete (EPC) has been widely used in civil engineering nowadays due to its excellent mechanical properties and advantages in processing. In this paper, a modeling study has been carried out on the flexural performance of EPC. Two classic micromechanics models, i.e. rule of mixture and Mori-Tanaka method, are introduced to predict the flexural strength of EPC with various epoxy resin contents. The comparison shows that the parallel model based on the rule of mixture attains a good agreement with the measured results when the epoxy resin content is sufficiently high to achieve strong adhesion between the aggregate and the epoxy resin. In contrast, the Mori–Tanaka method with the failure criterion dominated by the weakest phase fails to give acceptable prediction due to the unsuitability of its basic assumptions to EPC, particularly when the epoxy resin content is at relatively high levels.

scholarly journals Manufacturing and Characterization Process of Polymer Concrete with Aggregate From Pumice Stone and Corn Husk Fiber as A Filler

2019 ◽  
Vol 1 (1) ◽  
pp. 6-14
Author(s):  
Awan Maghfirah
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Epoxy Resin ◽  
Xrd Analysis ◽  
Polymer Concrete ◽  
Pumice Stone ◽  
Corn Husk ◽  
Three Samples ◽  
Pumice Sand

Research has been carried out regarding the manufacturing process of polymer concrete made from a mixture of pumice, sand (1: 1), corn husk fiber, epoxy and thinner resin. This research was conducted to determine the characterization of polymer concrete which will be tested physically and mechanically with the best composition mixture. The physical properties of polymer concrete which were analyzed namely density, porosity and water absorption; mechanical properties including impact strength, flexural strength and compressive strength, and polymer concrete microstructure analysis, namely SEM-EDX. The best results were obtained with a mixture of pumice, sand (1:1), corn husk fiber, epoxy and thinner resin. The result are as stated here, density: 1.84 g/cm3 with composition (49:49:2) 30 g epoxy resin, porosity : 0.44% with composition (50:50:0) 20 g epoxy resin, water absorption: 1.8% with composition (50:50:0) 25 g of epoxy resin. Whereas mechanical properties, on impact tests: 4.956 KJ/m2 with composition of (47:47:6) 25 g epoxy resin, flexural test: 22.22 MPa with composition of (45:45:0) 30 g epoxy resin, pressure test: 8.41 MPa with composition of (49:49:2) 30 g epoxy resin. XRD analysis shows that each of its constituents still have quartz, pumice, quartz, pumice-shaped hexagonal crystals, while corn husk fibers are amorphous crystals. The average sound absorption coefficient for the three samples (20%, 25%, and 30%) are 0.178; 0.152; and 0.234 at a frequency of 500 Hz - 6300 Hz, which meets the requirements of ISO 11654 and ASTM C.384.

Incorporation of Iraqi Rocks in the Production of Eco-Friendly Cement Mortar

2020 ◽  
Vol 38 (10A) ◽  
pp. 1522-1530
Author(s):  
Rawnaq S. Mahdi ◽  
Aseel B. AL-Zubidi ◽  
Hassan N. Hashim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Structural Properties ◽  
Mechanical Milling ◽  
Cement Mortar ◽  
Cement Mortars

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.

Influence of filler hybridization on thermomechanical properties of hemp/silver epoxy composite

2020 ◽  
pp. 096739112097811
Author(s):  
Munjula Siva Kumar ◽  
Santosh Kumar ◽  
Krushna Gouda ◽  
Sumit Bhowmik
Keyword(s):  
Thermal Conductivity ◽  
Silver Nanoparticles ◽  
Epoxy Polymer ◽  
Hybrid Composites ◽  
Conductive Filler ◽  
Weight Fraction ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Material Behavior ◽  
Good Crystallinity

The polymer composite material’s thermomechanical properties with fiber as reinforcement material have been widely studied in the last few decades. However, these fiber-based polymer composites exhibit problems such as fiber orientation, delamination, fiber defect along the length and bonding are the matter of serious concern in order to improve the thermomechanical properties and obtain isotropic material behavior. In the present investigation filler-based composite material is developed using natural hemp and high thermal conductive silver nanoparticles (SNP) and combination of dual fillers in neat epoxy polymer to investigate the synergetic influence. Among various organic natural fillers hemp filler depicts good crystallinity characteristics, so selected as a biocompatible filler along with SNP conductive filler. For enhancing their thermal conductivity and mechanical properties, hybridization of hemp filler along with silver nanoparticles are conducted. The composites samples are prepared with three different combinations such as sole SNP, sole hemp and hybrid (SNP and hemp) are prepared to understand their solo and hybrid combination. From results it is examined that, chemical treated hemp filler has to maximized its relative properties and showed, 40% weight % of silver nanoparticles composites have highest thermal conductivity 1.00 W/mK followed with hemp filler 0.55 W/mK and hybrid 0.76 W/mK composites at 7.5% of weight fraction and 47.5% of weight fraction respectively. The highest tensile strength is obtained for SNP composite 32.03 MPa and highest young’s modulus is obtained for hybrid composites. Dynamic mechanical analysis is conducted to find their respective storage modulus and glass transition temperature and that, the recorded maximum for SNP composites with 3.23 GPa and 90°C respectively. Scanning electron microscopy examinations clearly illustrated that formation of thermal conductivity chain is significant with nano and micro fillers incorporation.

scholarly journals Thermophysical Properties of Multifunctional Syntactic Foams Containing Phase Change Microcapsules for Thermal Energy Storage

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1790
Author(s):  
Francesco Galvagnini ◽  
Andrea Dorigato ◽  
Luca Fambri ◽  
Giulia Fredi ◽  
Alessandro Pegoretti
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Phase Change ◽  
Epoxy Resin ◽  
Storage Modulus ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Neat Epoxy ◽  
Low Density ◽  
Syntactic Foams

Syntactic foams (SFs) combining an epoxy resin and hollow glass microspheres (HGM) feature a unique combination of low density, high mechanical properties, and low thermal conductivity which can be tuned according to specific applications. In this work, the versatility of epoxy/HGM SFs was further expanded by adding a microencapsulated phase change material (PCM) providing thermal energy storage (TES) ability at a phase change temperature of 43 °C. At this aim, fifteen epoxy (HGM/PCM) compositions with a total filler content (HGM + PCM) of up to 40 vol% were prepared and characterized. The experimental results were fitted with statistical models, which resulted in ternary diagrams that visually represented the properties of the ternary systems and simplified trend identification. Dynamic rheological tests showed that the PCM increased the viscosity of the epoxy resin more than HGM due to the smaller average size (20 µm vs. 60 µm) and that the systems containing both HGM and PCM showed lower viscosity than those containing only one filler type, due to the higher packing efficiency of bimodal filler distributions. HGM strongly reduced the gravimetric density and the thermal insulation properties. In fact, the sample with 40 vol% of HGM showed a density of 0.735 g/cm3 (−35% than neat epoxy) and a thermal conductivity of 0.12 W/(m∙K) (−40% than neat epoxy). Moreover, the increase in the PCM content increased the specific phase change enthalpy, which was up to 68 J/g for the sample with 40 vol% of PCM, with a consequent improvement in the thermal management ability that was also evidenced by temperature profiling tests in transient heating and cooling regimes. Finally, dynamical mechanical thermal analysis (DMTA) showed that both fillers decreased the storage modulus but generally increased the storage modulus normalized by density (E′/ρ) up to 2440 MPa/(g/cm3) at 25 °C with 40 vol% of HGM (+48% than neat epoxy). These results confirmed that the main asset of these ternary multifunctional syntactic foams is their versatility, as the composition can be tuned to reach the property set that best matches the application requirements in terms of TES ability, thermal insulation, and low density.

Enhancing the mechanical and water resistance performances of bamboo particle reinforced polypropylene composite through cell separation

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dan Ren ◽  
Xuexia Zhang ◽  
Zixuan Yu ◽  
Hankun Wang ◽  
Yan Yu
Keyword(s):  
Water Absorption ◽  
Cell Separation ◽  
Water Resistance ◽  
Dynamic Mechanical Properties ◽  
Simple Method ◽  
Interface Modification ◽  
Wood Particles ◽  
Bamboo Fibers ◽  
Pp Composites ◽  
Mechanical Performances

AbstractIt is frequently observed that bamboo particle composites (BPCs) do not show higher mechanical performances than the corresponding wood particles composites (WPCs), although bulk bamboo is much stronger than wood in mechanical performances. Herein this phenomenon was demonstrated from the cell compositions in the applied bamboo particles. To address that, a simple method to physically separate bamboo fibers (BFs) and bamboo parenchyma cells (BPs) from a bamboo particle mixture was developed. Polypropylene (PP) composites with pure BFs, BPs, a mixture of BFs and BPs (BFs + BPs), wood particles (WPs) as fillers were prepared. The flexural and dynamic mechanical properties, water absorption, and thermal properties were determined. The BF/PP composites showed the best mechanical performances (MOR at 35 MPa, MOE at 2.4 GPa), followed by WP/PP, (BF + BP)/PP, and BP/PP. They also exhibited the lowest water absorption and thickness swelling. Little difference was found for the thermal decomposition properties. However, a lower activation energy of BF/PP compared with BP/PP implied an uneven dispersion of BFs and weaker interfacial interaction between BF and PP. The results suggest that the mechanical performances and water resistance of bamboo particle/polymer composites can be significantly improved through cell separation. However, interface modification should be applied if higher performances of BF/PP composites are required.

scholarly journals Preparation and Thermal Conductivity of Epoxy Resin/Graphene-Fe3O4 Composites

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2013
Author(s):  
Zhong Wu ◽  
Jingyun Chen ◽  
Qifeng Li ◽  
Da-Hai Xia ◽  
Yida Deng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Epoxy Resin ◽  
Thermomechanical Properties ◽  
Packaging Materials ◽  
Mass Ratio ◽  
Degree Of Orientation ◽  
Ep Matrix ◽  
Electrical Insulation Properties

By modifying the bonding of graphene (GR) and Fe3O4, a stable structure of GR-Fe3O4, namely magnetic GR, was obtained. Under the induction of a magnetic field, it can be orientated in an epoxy resin (EP) matrix, thus preparing EP/GR-Fe3O4 composites. The effects of the content of GR and the degree of orientation on the thermal conductivity of the composites were investigated, and the most suitable Fe3O4 load on GR was obtained. When the mass ratio of GR and Fe3O4 was 2:1, the thermal conductivity could be increased by 54.8% compared with that of pure EP. Meanwhile, EP/GR-Fe3O4 composites had a better thermal stability, dynamic thermomechanical properties, and excellent electrical insulation properties, which can meet the requirements of electronic packaging materials.

Thermal stable honokiol-derived epoxy resin with reinforced thermal conductivity, dielectric properties and flame resistance

2021 ◽  
Vol 412 ◽  
pp. 128647
Author(s):  
Jingjing Meng ◽  
Pengfei Chen ◽  
Rui Yang ◽  
Linli Dai ◽  
Cheng Yao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Properties ◽  
Epoxy Resin ◽  
Flame Resistance ◽  
Thermal Stable

scholarly journals A novel h-BN–RGO hybrids for epoxy resin composites achieving enhanced high thermal conductivity and energy density

RSC Advances ◽  
2017 ◽  
Vol 7 (38) ◽  
pp. 23355-23362 ◽  
Author(s):  
Tao Huang ◽  
Xiaoliang Zeng ◽  
Yimin Yao ◽  
Rong Sun ◽  
Fanling Meng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Energy Density ◽  
Epoxy Resin ◽  
High Thermal Conductivity ◽  
Resin Composites ◽  
Epoxy Resin Composites ◽  
Significant Attention

In recent decades, significant attention has been focused on developing composite materials with high thermal conductivity utilizing h-BN, which has outstanding thermal conductivity.

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