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Showing 1 to 16 of 16 for “"concrete crosstie"”.
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The mechanics of abrasion on concrete crosstie rail seats
… as one of the primary factors limiting concrete crosstie service life, particularly in heavy-haul freight operations. RSD refers to the degradation of the material at the contact interface between the concrete crosstie rail seat and the rail pad assembly that protects the bearing area of …
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Field test program of the concrete crosstie and fastening system
… rail program, the design and performance of concrete crossties and elastic fastening systems must be upgraded. As a part of a study aimed at improving concrete crossties and fastening systems, field experimentation was performed at the Transportation Technology Center (TTC) in Pueblo, CO by …
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Mechanistic analysis of concrete crosstie and fastening system using field-validated finite element model
… is to further investigate the performance of concrete crosstie and fastening system under vertical and lateral wheel load using finite element analysis, and explore possible improvement for current track design standard. The damage of fastening system is one of the most prevalent failure …
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Determination of load path through concrete crosstie and fastening system: a laboratory and field investigation
… of the load path from rail-wheel to precast concrete crossties. In this research, the behavior of crosstie and fastening system is investigated through material-level, component-level and system-level laboratory and field experiments. The system-level experiments use three primary test …
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Understanding the vertical load path under static and dynamic loads in concrete crosstie and fastening systems
… developing a mechanistic design approach for the crossties and fastening systems. It is important to follow the flow of forces through the system to understand the demands on each individual component. In spite of extensive research focusing on the vertical load path a lack of clear understanding …
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Quantification of rail seat load distributions on concrete crossties
… magnitude and distribution of load imparted to concrete crosstie rail seats. The rail seat load distribution is critical to the analysis of failure mechanisms associated with rail seat deterioration (RSD), the degradation of the concrete surface at the crosstie rail seat. RSD can lead to wide …
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Multifaceted approach for the analysis of rail pad assembly response
… rail construction worldwide, advancements in concrete crosstie fastening systems are required. A mechanistic design approach based on scientific principles, derived from extensive laboratory and field investigation and combined with computational analyses, has the potential to improve the …
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Analysis of the performance and failure of railroad concrete crossties with various track support conditions
In North America, the use of concrete crossties has increased steadily over the past decade as they have emerged as an economic alternative to timber crossties to accommodate heavy axle freight train loads. As the number of concrete crossties has grown, the importance of understanding the …
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Prestressed concrete railway crosstie support variability and its effect on flexural demand
… example, the current structural models used for concrete crosstie flexural analysis and design assume that the ballast bearing support is static and consistently located in a specific region under the crosstie. This assumption implies a linear behavior of the wheel-load bending moment …
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Freeze-thaw environment of precast concrete crossties and effect of vibration on fresh materials
High performance concrete is typically designed to achieve high strength and low permeability. These suppositions lead practitioners to install high performance concrete in outdoor environments assured that members will remain durable over scores of years. One such outdoor environment is in …
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Development of ice-bonded ballast in sub-freezing temperatures and its effect on maintenance operations during a winter rail break
… restrain the track system has been quantified by crosstie-type and ballast condition (e.g., consolidated or disturbed). Sub-freezing temperatures produce the largest differentials between the rail temperature and RNT (rail neutral temperature) [i.e., differential temperatures (dTs) exceeding 30⁰C …
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Analysis of the design of railroad track superstructure components for rail transit applications
… of the performance of prestressed monoblock concrete crossties and premium elastic fastening systems, this project aimed to quantify the behavior of the aforementioned track superstructure elements under different rail transit loading conditions. Instrumentation was deployed at three …
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Polypropylene fiber reinforced concrete in railway crossties
Cracking of concrete crossties is a performance problem that reduces service life and increases maintenance costs. While strong in compression, plain concrete is relatively weak and brittle under tensile stresses. Inclusion of synthetic polypropylene macro fibers in concrete is known to improve …
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Flexural behavior of prestressed concrete monoblock crossties
As the use of concrete crossties increases for heavy-haul freight railroad lines in North America, it is becoming more critical to improve the understanding of their flexural behavior. This improved understanding can help to optimize current design and maintenance practices for concrete crossties, …
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Increasing residual structural capacity of cracked concrete railroad crossties with polypropylene fibers
… research was to employ polypropylene fibers into concrete railroad crossties to increase its residual structural capacity once the concrete has cracked. The center negative flexural cracking is considered as a serious failure mode in concrete railroad crossties, which decreases structural capacity …
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Finite element analysis of railway track under vehicle dynamic impact and longitudinal loads
… element (FE) method. An FE model with multiple crossties and their accompanying fastening systems is developed and utilized in this study after being validated using field data. The results of the impact load study indicate that impact loading consists of direct wheel impact loads and track …