Effect of elevated in-service temperature on the mechanical properties and microstructure of particulate-filled epoxy polymers

Abstract

In civil engineering applications, epoxy-based polymers are subject to different environmental conditions including in-service temperature, which might accelerate their degradation and limit their application ranges. Recently, different particulate fillers were introduced to enhance the mechanical properties and reduce the cost of epoxy-based polymers. This paper addresses the effect of in-service elevated temperature (from room temperature to 80 o C) in particulate-filled epoxy based resin containing up to 60% by volume of fire retardant and fly ash fillers through a deep understanding of the microstructure and analysis of their mechanistic response. An improvement in the retention of mechanical properties at in-service elevated temperature was achieved by increasing the percentages of fillers. The retention of compressive and split tensile strength at 80 o C for the mix containing 60% fillers was 72% and 52%, respectively, which was significantly higher than the neat epoxy. Thermo-dynamic analysis showed an increase in glass transition temperature with the inclusion of fillers, while these mixes also experienced less weight loss compared to neat epoxy, indicating better thermal stability. Scanning electron microscopy images showed the formation of dense microstructures for particulate-filled epoxy based resin at elevated temperatures. This indicates that the particulate filled epoxy resin exhibits better engineering

Hybrid Epoxy Composites with Both Powder and Fiber Filler: A Review of Mechanical and Thermomechanical Properties

“…Numerous studies focus on the assessment of the impact on the characteristics of the epoxy materials of powder additives, such as: carbon nanotubes (CNTs), graphene; graphite, graphene, graphene nanosheets, fullerenes [23], metal carbides [24], silica [25], hydrated alumina powder [26], or natural filler [27,28]. Additionally, a lot of studies describe the modification of epoxy resin by simultaneously introducing two or more types of powder fillers into the epoxy matrix.…”

Experimental Investigation of Stochastic Mechanical Behavior of Cement Emulsified Asphalt Mortar under Monotonic Compression

“…Furthermore, by considering the lack of capability for characterizing the stochastic behaviors (variance), the applicability of the proposed model is wider, to some extent, compared with the presented model mentioned in this work. In summary, by examining the comparison results between the predictions and the experimental results in this work, it is verified that the proposed model is able to characterize the stochastic constitutive relationship (nonlinear and random stress-strain behaviors) of CA mortar under uniaxial monotonic compression with clear physical meaning based on a statistical damage approach, while some researchers used empirical relationships to predict certain mechanical behaviors of materials [11,22,24,25,48,59,60].…”

“…N denotes the total number of stress-strain curves, and σ i (ε) denotes the stress corresponding to the strain in i-th stress-strain curve. The complete stress-strain curves are plotted in Figure 5a, in which the nonlinearities of the stress-strain behaviors are fully captured while some researchers focus on discovering certain mechanical behaviors (e.g., strength, Young's modulus) [11,22,48,59,60]. The corresponding average curve and standard deviation curve generated by Equations (4) and (5) are illustrated in Figure 5b.…”

“…Furthermore, by considering the lack of capability for characterizing the stochastic behaviors (variance), the applicability of the proposed model is wider, to some extent, compared with the presented model mentioned in this work. In addition, from a practical point of view, although the proposed model can capture the nonlinearity and randomness of the stress-strain behavior, a number of models based on empirical and theoretical approaches proposed in foregoing studies [8,[21][22][23][24][25]35,[46][47][48][49][50][51][52][53][54]59,60,63] also provide lucid and acceptable results to predict relevant mechanical properties of certain materials. Thus, in order to further verify the applicability and accuracy for the proposed model, a comparison between the predicted mean stress-strain curve by using the proposed model and the model developed by Fu et al mentioned in the literature [35] were conducted.…”

Joint- or Crack-Opening Resistance Evaluation of Waterproofing Material and System for Structural Sustainability in Railroad Bridge Deck

“…High temperature during installation is also pertinent for securing long-term high adhesion performance as well. Ferdou et al investigate an optimal mixture design for epoxy-based polymer for application in concrete structures [ 22 ], and Khotbehsara et al provide an extensive study on the effect of high temperature on the mechanical properties of particulate-filled epoxy polymers used in infrastructures [ 23 ]. Su and Bloodworth also propose a numerical analysis method of sprayed-type waterproofing in tunnels that can simulate composite action, and while they provide a recommended design for spray-applied waterproofing, these studies attest that (1) waterproofing membranes must be properly evaluated against a myriad of factors, and most importantly against composite actions such as tension, compression and shear forces, and (2) a laboratory test method that can be used to evaluate these properties of waterproofing membranes is still in the process of being developed [ 24 ].…”