scholarly journals Viability Analysis of Waste Tires as Material for Rail Vibration and Noise Control in Modern Tram Track Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Caiyou Zhao ◽  
Ping Wang ◽  
Qiang Yi ◽  
Duo Meng
Keyword(s):  
Research Study ◽  
Dynamic Properties ◽  
Field Tests ◽  
Dynamic Tests ◽  
Frequency Range ◽  
Waste Tires ◽  
Viability Analysis ◽  
Railway Noise ◽  
Rubber Particles ◽  
Absorption Characteristics

This research study focused on the effect of using damping chamber elements made from waste tires on railway noise reduction. First, the energy absorption characteristics of damping chamber elements with various gradation combinations and compaction indices were measured in the laboratory using compression testing. The laboratory compression results demonstrated that the optimal gradation combination of damping chamber elements is as follows: the content of fine rubber particles is 10%, the content of coarse granules is 90%, and the optimal compaction index is 0.98. Next, the findings from the laboratory compression-test studies were used to produce damping chamber elements that were applied to a full-scale modern track model in the laboratory. The measurements of the dynamic properties indicated that the damping chamber elements could significantly reduce the vibration levels of the rail head. Finally, the damping chamber elements, which had been proven effective through laboratory dynamic tests, were widely applied to test rail sections in the field. The field tests demonstrated that damping chamber elements can significantly increase the track vibration decay rate in the frequency range of 200–10000 Hz. Therefore, damping chamber elements made from waste tires are able to control rail vibration and noise in modern tram track systems.

Experimental Investigation of a Bridge under Traffic Loadings

2014 ◽  
Vol 875-877 ◽  
pp. 1989-1993
Author(s):  
Feng Xiao ◽  
Gang S. Chen ◽  
J. Leroy Hulsey
Keyword(s):  
Dynamic Properties ◽  
Field Tests ◽  
Longitudinal Mode ◽  
Element Model ◽  
Modal Parameters ◽  
Dynamic Tests ◽  
Free Decay ◽  
Bridge Responses ◽  
Measurement Location ◽  
The Finite Element Model

A set of dynamic field tests were conducted on the Chulitna River Bridge recently. The Chulitna River Bridge, built in 1970, is located at Historic Mile Post 133 on the Parks Highway between Fairbanks and Anchorage, Alaska. Ambient free-decay response approach is used to estimate the dynamic properties of the bridge. Stationary and dynamic tests on the acceleration responses of the bridge recorded at different locations and in different directions during traveling vehicle passing the bridge. The natural frequencies are identified are characterized by the FFT methods. Results show that there are several components at 1.50, 2.20, 2.85, 3.23, 4.58 Hz are characterized, 2.85, 3.23, 4.58 Hz are bridge vertical mode; 1.50, 2.20 Hz are the longitudinal mode of bridge. Compared with the finite element model results, the measured results matched very well. The modal parameters identified from the bridge responses recorded at different locations are compared with each other to check their consistency, and are compared with FEM analytical results. The results demonstrated that (1) the modal parameters consistent with the FEM results; (2) The modal frequencies results are very sensitive to measurement locations, as such, multiple measurement points are necessary, and the optimization of measurement location is critical to conduct the test efficiently; (3). The identified modal properties of the Chulitna River Bridge could be used as benchmark in on-going health monitoring studies of this bridge.

Case study: Prediction and field tests of railway noise and effects of a low-height noise barrier

2020 ◽  
Vol 68 (4) ◽  
pp. 303-314
Author(s):  
Yuna Park ◽  
Hyo-In Koh ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Residential Areas ◽  
Railway Systems ◽  
Railway Noise ◽  
Sound Levels ◽  
Noise Barrier ◽  
The Difference ◽  
Reduction Effect ◽  
The Impact

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.

Dynamic properties of the mucky clay improved with the steel slag and the rubber particles

2021 ◽  
Vol 294 ◽  
pp. 123489
Author(s):  
Liyan Wang ◽  
Xing Xiao ◽  
Wenwei Ji ◽  
Aimable Ishimwe ◽  
Binghui Wang ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Steel Slag ◽  
Rubber Particles ◽  
Mucky Clay

Laboratory Evaluation of Rubberized Binder and Mix Containing a Low Content of Devulcanized Rubber Modifier

2020 ◽  
Vol 2674 (11) ◽  
pp. 53-63
Author(s):  
Yanlong Liang ◽  
David Jones ◽  
John T. Harvey ◽  
Jeffery Buscheck
Keyword(s):  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Laboratory Evaluation ◽  
Rubber Content ◽  
Area Index ◽  
Lower Phase ◽  
Waste Tires ◽  
Stiffness Reduction ◽  
Rubber Particles ◽  
Devulcanized Rubber

This paper evaluates the mechanical properties of rubberized asphalt binder and mix containing 5% and 10% rubber. This rubberized asphalt binder was manufactured in a field-blend process using devulcanized rubber particles, finer than 250 microns, derived from waste tires. Comparison between the rubberized binder and the base binder test results showed that the rubberized binders had higher complex moduli and lower phase angles at the grade temperature. They also had a higher percentage recovery in the multiple stress creep recovery test, and a significant creep stiffness reduction in the bending beam rheometer test. Given the low rubber content and small rubber particle size, this rubberized binder can be used in dense-graded mixes, whereas asphalt rubber binders, with larger rubber particles and higher rubber content (>15%), must be used in gap- or open-graded mixes. This rubberized dense-graded mix met the volumetric design criteria at the same binder content as the control mix prepared with the unmodified base binder. Laboratory tests on the mix included repeated load triaxial, Hamburg wheel track, flexural dynamic modulus, and beam fatigue. The rubberized mixes had slightly lower stiffnesses than the control mix, but better resistance to moisture damage, rutting, and fatigue cracking. A strong linear correlation was found between the carbonyl area index and the rheological properties of the long-term aged binder and fatigue life of the mixes. Based on these findings, these rubber-modified binders can be considered for use in dense-graded mixes to improve overall performance and make use of waste tires.

scholarly journals Frequency Response Stabilization and Comparative Studies of MET Hydrophone at Marine Seismic Exploration Systems

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1944 ◽  
Author(s):  
Egor Egorov ◽  
Anna Shabalina ◽  
Dmitry Zaitsev ◽  
Sergey Kurkov ◽  
Nikolay Gueorguiev
Keyword(s):  
Frequency Response ◽  
Field Tests ◽  
High Sensitivity ◽  
Seismic Exploration ◽  
Joint Stock Company ◽  
Experimental Sample ◽  
Frequency Range ◽  
Stock Company ◽  
Low Frequencies ◽  
Marine Seismic

Low frequency hydrophone with a frequency range of 1−300 Hz for marine seismic exploration systems has been developed. The operation principle of the hydrophone bases on the molecular electronic transfer that allows high sensitivity and low level self-noise at low frequencies (<10 Hz) to be achieved. The paper presents a stabilization method of the frequency response within the frequency range at a depth up to 30 m. Laboratory and marine tests confirmed the stated characteristics as well as the possibility of using this sensor in bottom marine seismic systems. An experimental sample of the hydrophone successfully passed a comparative marine test at Gelendzhik Bay (Black Sea) with the technical support of Joint-Stock Company (JSC) “Yuzhmorgeologiya”. One of the main results is the possibility of obtaining high-quality information in the field of low frequencies, which was demonstrated in the course of field tests.

Determination of dynamic properties of elastomers over broad frequency range

1983 ◽  
Vol 23 (2) ◽  
pp. 158-164 ◽  
Author(s):  
G. M. Smith ◽  
R. L. Bierman ◽  
S. J. Zitek
Keyword(s):  
Dynamic Properties ◽  
Frequency Range ◽  
Broad Frequency Range

scholarly journals Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5126
Author(s):  
Dhayalini Balasubramanian ◽  
Senthil Rajendran ◽  
Bhuvanesh Srinivasan ◽  
Nirmalakumari Angamuthu
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Foxtail Millet ◽  
Air Gap ◽  
Composite Panel ◽  
Sound Absorption Coefficient ◽  
Mass Content ◽  
Frequency Range ◽  
Backing Material ◽  
Absorption Characteristics

The current study deals with the analysis of sound absorption characteristics of foxtail millet husk powder. Noise is one the most persistent pollutants which has to be dealt seriously. Foxtail millet is a small seeded cereal cultivated across the world and its husk is less explored for its utilization in polymer composites. The husk is the outer protective covering of the seed, rich in silica and lingo-cellulose content making it suitable for sound insulation. The acoustic characterization is done for treated foxtail millet husk powder and polypropylene composite panels. The physical parameters like fiber mass content, density, and thickness of the composite panel were varied and their influence over sound absorption was mapped. The influence of porosity, airflow resistance, and tortuosity was also studied. The experimental result shows that 30-mm thick foxtail millet husk powder composite panel with 40% fiber mass content, 320 kg/m3 density showed promising sound absorption for sound frequency range above 1000 Hz. We achieved noise reduction coefficient (NRC) value of 0.54. In view to improve the performance of the panel in low-frequency range, we studied the efficiency of incorporating air gap and rigid backing material to the designed panel. We used foxtail millet husk powder panel of density 850 kg/m3 as rigid backing material with varying air gap thickness. Thus the composite of 320 kg/m3 density, 30-mm thick when provided with 35-mm air gap and backing material improved the composite’s performance in sound frequency range 250 Hz to 1000 Hz. The overall sound absorption performance was improved and the NRC value and average sound absorption coefficient (SAC) were increased to 0.7 and 0.63 respectively comparable with the commercial acoustic panels made out of the synthetic fibers. We have calculated the sound absorption coefficient values using Delany and Bezlay model (D&B model) and Johnson–Champoux–Allard model (JCA model) and compared them with the measured sound absorption values.

scholarly journals Fresh and Mechanical Properties of Self-Compacting Rubber Lightweight Aggregate Concrete and Corresponding Mortar

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jing Lv ◽  
Qiang Du ◽  
Tianhua Zhou ◽  
Zuoqian He ◽  
Kunlun Li
Keyword(s):  
Compressive Strength ◽  
Shear Stress ◽  
Lightweight Aggregate ◽  
Segregation Ratio ◽  
Plastic Viscosity ◽  
Lightweight Aggregate Concrete ◽  
Replacement Ratio ◽  
Aggregate Concrete ◽  
Waste Tires ◽  
Rubber Particles

Increasing amount of waste tires caused huge environment issues in recent years. Recycling concrete is an effective way. In this paper, waste tires are crushed into particles and incorporated in lightweight aggregate concrete to prepare a special concrete (self-compacting rubber lightweight aggregate concrete (SCRLC)). A detailed experimental research of effects of rubber particles on the properties of SCRLC and corresponding mortar is conducted. The results show that increasing the rubber particles replacement ratio leads to a raising of yield stress and plastic viscosity of mortar pastes. Flowability, filling capacity, and passing ability of SCRLC decline and the segregation resistance property of SCRLC improves as the rubber particles replacement ratio increases. Well, linear correlations between slump flow of SCRLC and shear stress of corresponding mortar pastes and segregation ratio of SCRLC and plastic viscosity of corresponding mortar pastes are obtained. In order to ensure that rubber lightweight aggregate concrete can compact by itself, the upper limit of shear stress of corresponding mortar pastes is 231.7 Pa and the lower limit of plastic viscosity of corresponding mortar pastes is 3.72 Pa·s. Compressive strength, splitting tensile strength, flexural strength, and elastic modulus of SCRLC and compressive strength of corresponding mortar decrease as the rubber particles replacement ratio increases. The 28-day compressive strength of SCRLC can meet the requirements of lightweight aggregate concrete structures until the rubber particles replacement ratio reaches 50%.

scholarly journals Dynamic tests on a steel-joist concrete-slab floor

1980 ◽  
Vol 7 (2) ◽  
pp. 213-224 ◽  
Author(s):  
J. H. Rainer
Keyword(s):  
Impact Test ◽  
Dynamic Properties ◽  
Concrete Slab ◽  
Subjective Assessment ◽  
Dynamic Tests ◽  
Nodal Lines ◽  
Mode 2 ◽  
Detailed Evaluation ◽  
Vibration Tests ◽  
Good Agreement

Dynamic properties have been determined for a composite steel-joist concrete-slab floor using heel impact and various shaker tests. The three modes located at 7.5, 12.4, and 18.7 Hz exhibited increasing numbers of nodal lines parallel to the joists.Application of vibration annoyance criteria for footsteps indicated that the floor was unsatisfactory. These criteria, presented in CSA Standard S16.1, Appendix G, had been derived specifically for the lowest mode of the floor. Detailed evaluation of the experimental results, however, shows that mode 1 has satisfactory vibration characteristics as a result of its high damping value, whereas mode 2 is identified as unsatisfactory. This is corroborated by subjective assessment. Vibration tests from walking steps were monitored and suitably filtered. Good agreement was found between the annoyance criteria derived from the heel impact test and those for "sustained vibrations" applied to the walking tests.Based on the dynamic properties of the floor, an assessment is made regarding the effectiveness of partitions and truss bracing for reducing footstep vibrations.

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