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 Residual Flexural Performance of Epoxy Polymer Concrete under Hygrothermal Conditions and Ultraviolet Aging

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3472
Author(s):  
Ma ◽  
Pan ◽  
Liu ◽  
Jiang ◽  
Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Flexural Strength ◽  
Aging Time ◽  
Uv Radiation ◽  
Aging Process ◽  
Epoxy Polymer ◽  
Polymer Concrete ◽  
Flexural Performance ◽  
Layered Beam

Epoxy polymer concrete (EPC) has found increasing applications in infrastructure as a rising candidate among civil engineering materials. In most of its service environments, EPC is inevitably exposed to severe weather conditions, e.g., violent changes in temperature, rain, and ultraviolet (UV) radiation. In this paper, we designed an accelerated aging test for EPC, which includes periodic variation of temperature and water spray, as well as intensive UV-light irradiation, imitating the outdoor environment in South China. The experimental results show that the flexural performance of EPC is found deteriorate with the aging time. An aging process equivalent to four years (UV radiation dose) results in up to 8.4% reduction of flexural strength. To explore the mechanisms of observed performance degradation, the EPC specimen in the four-point-bending test is considered as a layered beam. The analysis indicates that the loss of flexural load-carrying capacity of an aged EPC beam is dominated by the reduction of mechanical properties of the surface layer. The mechanical properties of the surface layer are closely associated with the aging of epoxy mortar, which can be approximated as a reciprocal function of the aging time. By introducing damage to the surface layer into the layered beam, the proposed model demonstrates a good ability to predict the residual flexural strength of EPC during the aging process

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 Enhanced flexural performance of epoxy polymer concrete with short natural fibers

2018 ◽  
Vol 61 (8) ◽  
pp. 1107-1113 ◽  
Author(s):  
Bin Hu ◽  
NanLi Zhang ◽  
YuTian Liao ◽  
ZhiWei Pan ◽  
YiPing Liu ◽  
...  
Keyword(s):  
Epoxy Polymer ◽  
Natural Fibers ◽  
Polymer Concrete ◽  
Flexural Performance

scholarly journals Flexural Performance Evaluation of Novel Wide Long-Span Composite Beams Used to Construct Lower Parking Structures

2019 ◽  
Vol 12 (1) ◽  
pp. 98
Author(s):  
Yun-Chul Choi ◽  
Doo-Sung Choi ◽  
Keum-Sung Park ◽  
Kang-Seok Lee
Keyword(s):  
Flexural Strength ◽  
Composite Beams ◽  
Steel Beams ◽  
Test Results ◽  
Element Analysis ◽  
Bending Tests ◽  
Flexural Performance ◽  
Long Span ◽  
Global And Local ◽  
Good Agreement

Efficient parking structures are urgently required in Korea. The design of parking structures more than 8 m in height is difficult because both fire and seismic resistance must be considered. Existing designs are uneconomical and conservative. However, the design of parking structures less than 8 m in height is relatively simple and there are few restrictions to the construction. It is essential to optimize the design of parking structures less than 8 m in height. Here, we describe novel wide long-span composite beams that reduce the story height of low parking structures. The flexural capacity of seven of the beams was evaluated; all beams were loaded at two points prior to monotonic bending tests. We also performed finite element analysis (FEA) based on the material properties of the test specimens, and compared the results to those of the structural tests. The flexural strength of the wide composite steel beams increased by approximately 20% as the steel thickness rose by 3 mm, from 6 to 9 mm. The rebar shape (triangular or rectangular) did not affect flexural strength. The flexural strength of beams without rebar was 10% less than that of beams with rebar. The FEA and test results were in good agreement. The section plastic moments were free from global and local instability.

Study on the Composites of Phenol Formaldehyde Resin/Graphite Reinforced by Milled Carbon Fibers for Bipolar Plates

2010 ◽  
Vol 156-157 ◽  
pp. 1090-1096
Author(s):  
Wei Qiang Wang ◽  
Ai Ju Li ◽  
Ming Ming You ◽  
Bin Xia
Keyword(s):  
Electrical Conductivity ◽  
Liquid Phase ◽  
Flexural Strength ◽  
Carbon Fibers ◽  
Phenol Formaldehyde ◽  
Resin Content ◽  
Liquid Phase Oxidation ◽  
Bipolar Plates ◽  
Air Oxidation ◽  
Phase Oxidation

Composites of phenol formaldehyde (PF) resin/graphite reinforced by milled carbon fibers (MCFs) for bipolar plates are obtained by hot compression molding. The raw materials of the MCF particles, PF resin powder and graphite powder are simply dry powder ball milled and mixed. The effects of PF resin content and the content, granularity and surface treatment methods, such as air oxidation and Fenton/ultraviolet (UV) liquid-phase oxidation of MCFs on the electrical conductivity and flexural strength of the composites are measured by methods of four-point probe technique and three point flexural test, and the fracture patterns of the composites are analyzed by scanning electron microscope (SEM). The results indicate that the electrical conductivity decreases and flexural strength increases with the increase of PF resin content. Especially, the values of electrical conductivity and flexural strength can reach 165.28 S.cm-1 and 55.11MPa respectively when the PF resin content was 17% in weight. The properties of composites reinforced by air oxidation treated MCFs are better than those by liquid-phase oxidation treated one. The electrical conductivity and flexural strength of the composites are 208.12S.cm-1 and 57.44 MPa when they reinforced by 5% MCFs which treated by air oxidation at 450 . Compared with the nonreinfoced composites, the properties of reinforced composites increase 25.92% in electrical conductivity and 4.23% in flexural strength.

scholarly journals Study of Mechanical Properties of an Eco-Friendly Concrete Containing Recycled Carbon Fiber Reinforced Polymer and Recycled Aggregate

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4592
Author(s):  
Chen Xiong ◽  
Tianhao Lan ◽  
Qiangsheng Li ◽  
Haodao Li ◽  
Wujian Long
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Fiber Reinforced Polymer ◽  
Recycled Aggregate ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Flexural Performance ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

This study investigates the feasibility of collaborative use of recycled carbon fiber reinforced polymer (RCFRP) fibers and recycled aggregate (RA) in concrete, which is called RCFRP fiber reinforced RA concrete (RFRAC). The mechanical properties of the composite were studied through experimental investigation, considering different RCFRP fiber contents (0%, 0.5%, 1.0%, and 1.5% by volume) and different RA replacement rates (0%, 10%, 20%, and 30% by volume). Specifically, ten different mixes were designed to explore the flowability and compressive and flexural strengths of the proposed composite. Experimental results indicated that the addition of RCFRP fibers and RA had a relatively small influence on the compressive strength of concrete (less than 5%). Moreover, the addition of RA slightly decreased the flexural strength of concrete, while the addition of RCFRP fibers could significantly improve the flexural performance. For example, the flexural strength of RA concrete with 1.5% RCFRP fiber addition increased by 32.7%. Considering the good flexural properties of the composite and its potential in reducing waste CFRP and construction solid waste, the proposed RFRAC is promising for use in civil concrete structures with high flexural performance requirements.

Utilization of Waste Packaging Glass as Progressive Filler in Polymer Anchor Material Based on Epoxy Resin

2019 ◽  
Vol 887 ◽  
pp. 40-47
Author(s):  
Tomáš Žlebek ◽  
Jakub Hodul ◽  
Rostislav Drochytka
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Epoxy Resin ◽  
High Strength Concrete ◽  
Chemical Resistance ◽  
Negative Impact ◽  
High Strength ◽  
Pull Out ◽  
Pull Out Strength ◽  
Packaging Glass

The work deals with the use of waste glass to the polymer anchor material based on epoxy resin, primarily for anchoring to a high strength concrete (HSC). The main aim was to use the largest possible amount of the waste packaging glass by reducing the amount of epoxy resin, which is an expensive material and its production has a negative impact on the environment. Within the experimental verification, the influence of waste packaging glass fraction 0–0.63 mm on the final properties of the polymer anchoring material was observed. To determine the optimal formulation compressive strength, flexural strength, chemical resistance, shrinkage and pull-out test were performed. Based on the evaluation of the results the optimal percentage of filling was determined, when the polymer anchor material showed high strengths, minimal shrinkage, good chemical resistance, optimal consistency for anchoring into the HSC and high anchor bolt pull-out strength.

scholarly journals Preparation and properties studies of UV-curable silicone modified epoxy resin composite system

2018 ◽  
Vol 16 (1_suppl) ◽  
pp. 170-176 ◽  
Author(s):  
Zhouhui Yu ◽  
Aiyong Cui ◽  
Peizhong Zhao ◽  
Huakai Wei ◽  
Fangyou Hu
Keyword(s):  
Heat Resistance ◽  
Epoxy Resin ◽  
Resin Composite ◽  
Curing Kinetics ◽  
Resin Content ◽  
Silicone Resin ◽  
Two Phase ◽  
Uv Curable ◽  
Humidity Resistance ◽  
Modified Epoxy

Introduction: Modified epoxy suitable for ultraviolet (UV) curing is prepared by using organic silicon toughening. The curing kinetics of the composite are studied by dielectric analysis (DEA), and the two-phase compatibility of the composite is studied by scanning electron microscopy (SEM). Methods: The tensile properties, heat resistance, and humidity resistance of the cured product are explored by changing the composition ratio of the silicone and the epoxy resin. Results: SEM of silicone/epoxy resin shows that the degree of cross-linking of the composites decreases with an increase of silicone resin content. Differential thermal analysis indicates that the glass transition temperature and the thermal stability of the composites decrease gradually with an increase of silicone resin content. The thermal degradation rate in the high temperature region, however, first decreases and then increases. In general, after adding just 10%–15% of the silicone resin and exposing to light for 15 min, the composite can still achieve a better curing effect. Conclusions: Under such conditions, the heat resistance of the cured product decreases a little. The tensile strength is kept constant so that elongation at breakage is apparently improved. The change rate after immersion in distilled water at 60°C for seven days is small, which shows excellent humidity resistance.

Study on the Preparation of Green and Environmentally Friendly High Toughness Cementitous Composites with Large Amount of Fly Ash

2020 ◽  
Vol 996 ◽  
pp. 97-103
Author(s):  
Xiang Rong Cai ◽  
Bai Quan Fu ◽  
Zhi Gang Liu
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Strain Hardening ◽  
Cementitious Composites ◽  
Special Focus ◽  
Type I ◽  
Flexural Performance ◽  
High Toughness ◽  
Four Point Bending ◽  
Pva Fiber

In order to reduce the environmental burden and the energy consumption of PVA fiber reinforced high toughness cementitious composites, special focus is placed on the influence of fly ash type and content and curing type on the flexural performance of high toughness cementitious composites through four-point bending tests. The high toughness cementitious composites without fly ash have been used in the program for comparison purpose. The tests results show that, compared with the basic high toughness cementitious composites, the flexural strength decreases and the deflection increases with the s/b increasing when the fly ash is added. The increase in fly ash content results in an improvement of strain hardening property and increases in both flexural strength and deflection, which show that fly ash is benefit to the pseudo strain hardening performance. However the effects of fly ash type and curing type are not obvious on the load but obvious on the deflection. The deflection of high toughness cementitious composites with type I fly ash or water curing is higher than that of type II or standard curing. It is demonstrated that all the high toughness cementitious composites studied in this paper exhibit strain-hardening and multiple cracking through adding fly ash.

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