Effects of thermal histories on carbon fiber/polyamide 6 microcomposite load transfer efficiency: Crystallization, modulus, and measurement

2016 ◽  
Vol 39 (1) ◽  
pp. 102-109 ◽  
Author(s):  
Hongfu Li ◽  
Yanfei Zhang ◽  
Yang Wang ◽  
Boming Zhang
Keyword(s):  
Carbon Fiber ◽  
Load Transfer ◽  
Polyamide 6 ◽  
Transfer Efficiency ◽  
Thermal Histories ◽  
Load Transfer Efficiency

Development of Dowel Looseness Prediction Model for Jointed Concrete Pavements

1996 ◽  
Vol 1525 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Neeraj Buch ◽  
Dan G. Zollinger
Keyword(s):  
Prediction Model ◽  
Load Transfer ◽  
Laboratory Data ◽  
Fault Prediction ◽  
Transfer Efficiency ◽  
Oxide Content ◽  
Concrete Pavements ◽  
Bearing Stress ◽  
Load Transfer Efficiency ◽  
Jointed Concrete Pavements

The results of an in-depth study of factors that affect dowel looseness in jointed concrete pavements are presented. The laboratory investigation revealed the influence of aggregate type (in relation to oxide content), aggregate texture and shape, bearing stress (dowel diameter and crack width), load magnitude, and number of load cycles on the magnitude of dowel looseness and the subsequent loss in load transfer efficiency across saw-cut joints. A discussion is included on the development of an empirical-mechanistic dowel looseness prediction model based on the experimental results. Results of the sensitivity analysis of the dowel looseness prediction model (using laboratory data) are also presented. An associated scope of this research was to develop a relationship between dowel looseness and loss of load transfer efficiency. The sequential use of the dowel looseness prediction model and its relationship to load transfer efficiency allows the design engineer to predict load transfer characteristics of a joint, based on calculated (or measured) dowel looseness. The framework suggested to predict dowel looseness can then be incorporated into a fault prediction model for doweled joints.

scholarly journals A Rapid Detection Method for Bridges Based on Impact Coefficient of Standard Bumping

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Xiaolan Liu ◽  
Xianmin Zhang ◽  
Yadong Wang
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Evaluation Method ◽  
Load Transfer ◽  
Amplitude Ratio ◽  
Load Test ◽  
Transfer Efficiency ◽  
Mountain Areas ◽  
Load Transfer Efficiency ◽  
Dowel Bar

The evaluation method of load transfer efficiency using falling weight deflectometer is unworkable in remote mountain areas and transportation difficult region. Therefore, a novation method of load transfer efficiency evaluation is proposed using the index of amplitude ratio. Finite element method is applied to study the influence of dowel bar parameters (diameter, length, spacing, and elastic modulus) and pavement structures parameters (thickness and modulus) on load transfer efficiency, frequency, and the ratio of amplitude. Results of finite element model show that the effects of dowel bar and pavement structure parameters on load transfer efficiency and the ratio of amplitude are similar. The load transfer efficiency, frequency, and the ratio of amplitude enhance with the increase of dowel bar diameter, length, and elastic modulus and the decrease of dowel bar spacing. The subgrade modulus has more significant influence on the load transfer efficiency, frequency, and the ratio of amplitude than other pavement parameters. Polynomial function method is utilized to established load transfer mode between deflection-based load transfer efficiency and the ratio of amplitude. The feasibility and reliability of new method is verified by static and dynamic load test. All results are helpful for the development of highway engineering and airport engineering.

Research on Load Transfer Efficiency of GFRP Dowel in Jointed Plain Concrete Pavement

2012 ◽  
Vol 178-181 ◽  
pp. 1152-1155 ◽  
Author(s):  
Luo Ke Li ◽  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Zhong Jun Xue
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Element Model ◽  
Transfer Efficiency ◽  
Engineering Practice ◽  
Concrete Pavements ◽  
Load Transfer Efficiency

In a jointed plain concrete pavements, the dowel bar system are used to provide lateral load transfer across transverse joint. Corrosion of commonly used steel dowel in engineering practice reduces their service life and costs considerable maintenance and repair spending for concrete pavements. The objective of this study focus primarily on the performance of none eroded GFRP dowel on LTE( load transfer efficiency) with the help of a three-dimensional finite-element model. The amount of LTE can be obtained directly from comparing the maximum deflection of the concrete slab and the level tensile stress under the concrete slab. According to the finite element results, the larger-diameter GFRP dowel are found to perform the best in this study.

scholarly journals Laboratory Characterization of The Load Transfer-Crack Width Relation for Innovative Short Concrete Slabs Pavements

2020 ◽  
Vol 15 (1) ◽  
pp. 232-250 ◽  
Author(s):  
Mauricio Pradena ◽  
Lambert Houben ◽  
Andrés César
Keyword(s):  
Structural Design ◽  
Crack Width ◽  
Load Transfer ◽  
Plain Concrete ◽  
Design Methods ◽  
Transfer Efficiency ◽  
Concrete Slabs ◽  
Concrete Pavements ◽  
Load Transfer Efficiency ◽  
Reduced Scale

Aggregate interlock is the dominant load transfer mechanism in non-dowelled Jointed Plain Concrete Pavements, as the innovative short concrete slabs. Although the Load Transfer Efficiency of this pavement innovation is based on that mechanism, the structural design methods do not relate the Load Transfer Efficiency by aggregate interlock with its direct cause, which is the Crack Width under the joints. The objective of the present article is to characterise in the laboratory the Load Transfer Efficiency−Crack Width relation for innovative short slabs Jointed Plain Concrete Pavements. Additionally, as an alternative to large-scale laboratory tests to study the Load Transfer Efficiency, a practical test on a reduced scale is proposed. The results confirmed that short slabs Jointed Plain Concrete Pavements with high-quality aggregates are able to provide adequate Load Transfer Efficiency (above 70%) without dowels bars. Based on the laboratory results, complemented with previous field data, a Load Transfer Efficiency−Crack Width curve is proposed and made available for structural design methods of short slabs Jointed Plain Concrete Pavements. Finally, the laboratory test on a reduced scale is useful to develop specific Load Transfer Efficiency−Crack Width relations using standard equipment available in traditional concrete laboratories.

scholarly journals Tailoring nanocomposite interfaces with graphene to achieve high strength and toughness

2020 ◽  
Vol 6 (42) ◽  
pp. eaba7016
Author(s):  
Ningning Song ◽  
Zan Gao ◽  
Xiaodong Li
Keyword(s):  
Self Assembly ◽  
Load Transfer ◽  
Low Cost ◽  
High Strength ◽  
Transfer Efficiency ◽  
Assembly Mechanism ◽  
Shear Mixing ◽  
Load Transfer Efficiency ◽  
Predicted Values ◽  
Dynamics Simulations

The nanofiller reinforcing effect in nanocomposites is often far below the theoretically predicted values, largely because of the poor interfacial interaction between the nanofillers and matrix. Here, we report that graphene-wrapped B4C nanowires (B4C-NWs@graphene) empowered exceptional dispersion of nanowires in matrix and superlative nanowire-matrix bonding. The 0.2 volume % B4C-NWs@graphene reinforced epoxy composite exhibited simultaneous enhancements in strength (144.2 MPa), elastic modulus (3.5 GPa), and ductility (15%). Tailoring the composite interfaces with graphene enabled effective utilization of the nanofillers, resulting in two times increase in load transfer efficiency. Molecular dynamics simulations unlocked the shear mixing graphene/nanowire self-assembly mechanism. This low-cost yet effective technique presents unprecedented opportunities for improving nanocomposite interfaces, enabling high load transfer efficiency, and opens up a new path for developing strong and tough nanocomposites.

Study on Dowel Bar Retrofit on Rigid Pavement to Load Transfer Restoration

2013 ◽  
Vol 857 ◽  
pp. 160-165
Author(s):  
Peng Peng ◽  
Bo Tian ◽  
Xiu Xiong Mo ◽  
Kai Min Niu
Keyword(s):  
Load Transfer ◽  
Cost Effective ◽  
Element Model ◽  
Maximum Tensile Stress ◽  
Transfer Efficiency ◽  
Engineering Practice ◽  
Construction Technique ◽  
Aggregate Interlocking ◽  
Load Transfer Efficiency ◽  
Dowel Bar

Finite element model analysis was performed with respect to patterns of load transfer relying on the action of aggregate interlocking and on the concurrent action of aggregate interlocking and dowel bars. The best timing for dowel bar retrofit was determined by way of increase in load transfer efficiency and maximum tensile stress borne at joints. The situation of dowel bar retrofit to restore load transfer efficiency was verified by way of onsite tests and economic analysis performed before we came to the conclusion that the way of dowel bar retrofit to restore load transfer efficiency is fairly cost effective. The construction technique of dowel bar retrofit to restore load transfer efficiency is finally summarized in light of engineering practice.

scholarly journals Load Transfer Efficiency Based on Structural Deflection Assessment of the Precast Floating Track

2020 ◽  
Vol 11 (1) ◽  
pp. 120
Author(s):  
Linh Vu ◽  
Yun Suk Kang
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Transfer Efficiency ◽  
Element Analysis ◽  
Railway Stations ◽  
Vibration Isolators ◽  
Slab Track ◽  
Test Standards ◽  
Load Carrying ◽  
Load Transfer Efficiency

In Korea, a precast floating track with anti-vibration isolators was recently developed to reduce the vibration and noise in urban railway stations, without disrupting train operations. This precast floating slab track is a newly developed structure and differs from existing conventional slab tracks. In this study, a Finite Element Method program (MIDAS CIVIL 2019) was used to analyze the load-carrying ability of structures under the train axle loads. After finishing the design, to understand more precisely about load transfer efficiency of this type of track, an assembly test (two load cases) was conducted with three precast panels (with rail 60 K mounted on) and compared with Finite Element Analysis results. The final results satisfied the test standards in Korea, which confirms that the precast floating track has an acceptable safety factor and structural behavior.

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