The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Jianzhong Pei - One of the best experts on this subject based on the ideXlab platform.
-
unified laboratorial evaluation of Interlayer Bond property in asphalt pavements based on strength parameters
Construction and Building Materials, 2021Co-Authors: Kai Yang, Jianzhong PeiAbstract:Abstract Interlayer Bonding properties are attracting more attention due to their significant effect on the service life of multilayered pavements. In this work, five widely-used tack coats were applied and the optimum tack coat rate was proposed based on the Interlayer shear strength. Then, three Interlayer strength parameters (i.e., shear, tensile, flexural strength) and interface stiffness were selected to characterize the Interlayer Bonding property. The Interlayer Bonding percentage was utilized to quantify the interface Bond by above mechanical parameters. The results show the optimum tack coat rate exists corresponding to the peak shear stress. All the Interlayer strength parameters are highly temperature-dependent. The ranking of five tack coats is the same by utilizing the three strength parameters. Epoxy resin binder can be recommended as the tack coat of pavement Interlayer material, which is associated with the better shear, tensile and flexural resistance. Finally, an evaluation method of interface Bonding property is proposed based on the shear, tensile, flexural strength and Interlayer Bonding percentage. This work remedies some of the shortcomings of current evaluation methods, such as only considering a single strength parameter.
Dujin Wang - One of the best experts on this subject based on the ideXlab platform.
-
fused filament fabrication of polymer materials a review of Interlayer Bond
Additive manufacturing, 2021Co-Authors: Xia Gao, Xiao Kuang, Dujin WangAbstract:Abstract Fused filament fabrication (FFF), one of the most promising additive manufacturing (AM) methods has attracted considerable attention to date. Although FFF is evolving into a manufacturing tool with significant technological and material advancements, there remains a challenge to transfer FFF-printed parts into functional objects for practical applications. Polymer components fabricated by FFF technique exhibit weak and anisotropic mechanical properties compared to their counterparts by conventional processing. The limited mechanical property for the FFF-printed parts is a result of weak Interlayer Bond interface that develops during the layer-wise deposition process. This review documents recent advances on the Bond interface in FFF-printed parts in aspects of its mechanisms, characterization and enhancement methods. The main objective is to provide a comprehensive understanding of the process-structure-properties of Interlayer Bond in FFF technique.
-
the role of poly ethylene glycol on crystallization Interlayer Bond and mechanical performance of polylactide parts fabricated by fused filament fabrication
Additive manufacturing, 2020Co-Authors: Xia Gao, Daijun Zhang, Dujin WangAbstract:Abstract The interfacial Bond quality between adjacent layers determines the mechanical properties of 3D parts fabricated by fused filament fabrication (FFF) method. For semi-crystalline polymers, molecular diffusion and entanglements as well as crystallization behaviors have been reported to exert influence on the Interlayer Bond quality for FFF-printed parts. To improve the Interlayer Bond quality and decrease the mechanical anisotropy, poly (ethylene glycol) (PEG) with various molecular weights are used to modify polylactide (PLA) printing materials. With the addition of PEGs, the Interlayer Bond strength for FFF-printed PLA parts is enhanced, which decreases the mechanical anisotropy from 32 % for neat PLA parts to 16 % for PLA/PEG parts. Moreover, PEGs with molecular weight larger than 8000 g/mol have profound effects on the mechanical properties of PLA parts. However, PEGs exert minor effect on the crystallization behaviors of FFF-printed PLA parts, although they can accelerate the crystallization kinetics for bulk PLA. By means of DSC method, shear-induced crystallization is proved to dominate the crystallization behaviors of PLA parts. Altogether, the improved mechanical properties for PLA parts with the addition of PEGs are associated with the enhanced molecular diffusion and entanglements at the Bond zone, rather than the crystallinity of PLA parts.
Kangting Yin - One of the best experts on this subject based on the ideXlab platform.
-
effect of structural build up on Interlayer Bond strength of 3d printed cement mortars
Materials, 2021Co-Authors: Tinghong Pan, Yaqing Jiang, Yu Wang, Kangting YinAbstract:Understanding the relationship between the intrinsic characteristics of materials (such as rheological properties and structural build-up) and printability and controlling intrinsic characteristics of materials through additives to achieve excellent printability is vital in digital concrete additive manufacturing. This paper aims at studying the effects of material's structural build-up on the Interlayer Bond strength of 3DPC with different time gaps. Structural build-up can indirectly affect the Interlayer Bond strength by affecting the surface moisture of concrete. Based on the structural build-up of 3DPC, a new parameter, maximum operational time (MOT), is proposed, which can be considered as the limit of time gap to ensure high Interlayer Bond strength. Slump-retaining polycarboxylate superplasticizer (TS) slightly slows down the physical flocculation rate, but increases the maximum operational time of the cement paste. Nano clay significantly increases the sort-term structural build-up rate and has the function of internal curing and water retaining. Composite with nano-clay and TS can reduce the loss of surface moisture of 3D printed layers, prevent the formation of interface weak layer, and increase the Interlayer Bond strength between printed layers. This contribution can provide new insight into the design of 3D-printed ink with good extrudability, outstanding buildability, and excellent Interlayer Bond strength.
Dimitrios Maroudas - One of the best experts on this subject based on the ideXlab platform.
-
formation and mechanical behavior of nanocomposite superstructures from Interlayer Bonding in twisted bilayer graphene
ACS Applied Materials & Interfaces, 2018Co-Authors: Mengxi Chen, Andre R Muniz, Dimitrios MaroudasAbstract:We report a comprehensive study on the design of two-dimensional graphene-diamond nanocomposite superstructures formed through Interlayer covalent Bonding of twisted bilayer graphene with commensurate bilayers. The Interlayer Bonding is induced by patterned hydrogenation that leads to the formation of superlattices of two-dimensional nanodiamond domains embedded between the two graphene layers. We generalize a rigorous algorithm for the formation of all possible classes of these superstructures: the structural parameters employed to design such carbon nanocomposites include the commensurate bilayer's twist angle, the stacking type of the nanodomains where the Interlayer Bonds are formed, the Interlayer Bond pattern, and the Interlayer C-C Bond density that is proportional to the concentration of sp3-hybridized Interlayer-Bonded C atoms. We also analyze systematically the mechanical behavior of these nanocomposite superstructures on the basis of molecular-dynamics simulations of uniaxial tensile straining tests according to a reliable interatomic Bond-order potential. We identify a range of structural parameters over which the fracture of these superstructures is ductile, mediated by void formation, growth, and coalescence, contrary to the typical brittle fracture of graphene. We introduce a ductility metric as an order parameter for the brittle-to-ductile transition, demonstrate its direct dependence on the fraction of sp3-hybridized Interlayer-Bonded C atoms, and show that increasing the fraction of Interlayer-Bonded C atoms beyond a critical level in certain classes of these superstructures induces their ductile mechanical response.
Manfred N Partl - One of the best experts on this subject based on the ideXlab platform.
-
comparison of Interlayer Bond behavior due to ageing
2016Co-Authors: Christiane Raab, A Abd El O Halim, James Grenfell, Manfred N PartlAbstract:The research focuses on the question of the influence of age on the Interlayer Bonding properties of two layered specimens. The evaluation compares and discusses the behavior of different datasets from laboratory and in situ pavements from Switzerland, United Kingdom and Italy using traditional data evaluation and Artificial Neural Network (ANN) analysis. The results show that it is possible to use ANN techniques to derive models from datasets and to predict Interlayer Bond strength. The findings demonstrate that age has a positive effect on the Interlayer Bond of asphalt pavements and that long term oven ageing can lead to similar results as in situ ageing. In addition it was found that the positive effect of ageing is greater when a tack coat is used. According to the results of the investigation a linear model from all data would predict that maximum strength may roughly increase by 1 % per month over a period of 10 years.
-
mechanical testing of Interlayer Bonding in asphalt pavements
2013Co-Authors: Francesco Canestrari, Manfred N Partl, Gilda Ferrotti, Xiaohu Lu, Anne Millien, Christophe Petit, Annabelle Phelipotmardele, H Piber, Christiane RaabAbstract:Steadily increasing requirements on pavement performance properties, in terms of bearing capacity and durability, as well as new innovative developments regarding pavement materials and construction, are observed worldwide. In this context Interlayer Bonding at the interfaces of multi-layered bituminous systems is recognized as a key issue for the evaluation of the effects, in terms of stress-strain distribution, produced by traffic loads in road pavements. For this reason a correct assessment of Interlayer Bonding is of primary importance, and research efforts should be addressed in order to improve the lack of correlation and/or harmonization among test methods. Following this principle RILEM TG 4 organized an interlaboratory test in order to compare the different test procedures to assess the Interlayer Bonding properties of asphalt pavement. The results of the experimental research are presented with a preliminary overview of basic elements, test methods and experimental investigations on Interlayer Bonding. Then the RILEM TG 4 experimental activities, based on the construction of three real- scale pavement sections, are presented in detail. Each pavement section was composed of two layers, and three different interface conditions were chosen. The first pavement was laid without interface treatment and the others with two different types of emulsion. Fourteen laboratories from 11 countries participated in this study and carried out shear or torque tests on 1,400 cores. The maximum shear or torque load and the corresponding displacement were measured, and the shear or torque strength was calculated as a function of the following parameters: diameter, test temperature, test speed, stress applied normal to the interface and age of the specimen. The results of this study are presented in terms of precision and correlations regarding the parameters which results in useful information on asphalt pavement Interlayer Bond tests.
-
Interlayer Bond testing using a model material
Construction and Building Materials, 2012Co-Authors: Christiane Raab, A Abd El O Halim, Manfred N PartlAbstract:Abstract Bond problems between asphalt layers are attracting more attention due to the continuous refinement of pavement design methodologies. However, research nowadays is mainly focussing on the practical evaluation of specific pavement material types and tack coat materials. In this paper, the influence of aggregate interlock combining different aggregate sizes on the shear strength between two layers is evaluated. Using a model material composed of idealized aggregates represented by steel balls and 10/20 penetration graded bitumen, this study is investigating the question on how the ball size and/or a combination of different ball sizes influence Interlayer shear strength and shear stiffness. Shear Bond testing was done using the Layer Parallel Shear Test (LPDS) with two different test speeds as well as a Shear Box with varying normal stress.
-
developing a framework for standardization of Interlayer Bond of asphalt pavements
Transportation Research Board 91st Annual MeetingTransportation Research Board, 2012Co-Authors: Christiane Raab, A Abd El O Halim, Manfred N PartlAbstract:The main goal of this research was to develop a framework for understanding the mechanisms that operate and govern the mechanical behavior of the Interlayer Bond between the layers of asphalt pavements, mainly the top asphalt layer and the one immediately underneath it. One of the basic requirements for developing the framework was the understanding and determination of the main mechanisms that govern the Interlayer Bond. Therefore, an extensive literature review followed by a comprehensive experimental modeling was carried out by using an idealized model material. Furthermore, the effects of the critical parameters were determined and quantified. This was achieved by a parametric experimental study which investigated the effect of moisture, temperature and the gap width between the shearing rings on the Bond strength. After understanding the mechanisms and the effects of the critical parameters, a model using artificial neural network technique was evaluated and the contributing variables and their influences on the Interlayer Bond were predicted.