scholarly journals Investigation on Interface Damage between Cement Concrete Base Plate and Asphalt Concrete Waterproofing Layer under Temperature Load in Ballastless Track

2020 ◽  
Vol 10 (8) ◽  
pp. 2654
Author(s):  
Xianhua Chen ◽  
Yu Zhu ◽  
Degou Cai ◽  
Gang Xu ◽  
Tao Dong
Keyword(s):  
Dynamic Response ◽  
Crack Propagation ◽  
Asphalt Concrete ◽  
Base Plate ◽  
Cement Concrete ◽  
Damage Initiation ◽  
Interface Damage ◽  
Ballastless Track ◽  
Concrete Base ◽  
Temperature Load

The interfacial bond between cement concrete base plate (CCBP) and asphalt concrete waterproofing layer (ACWL) is a weak portion in the newly developed Chinese high-speed railway ballastless track. The interface damage caused due to fluctuating temperature load and dynamic train load is one of the most critical problems in Northern China. This paper aims to investigate the interface damage evolution process under temperature load via experimental and simulation analysis. Full-scale transverse shear tests were performed to explore the interface bond-slip mode of the adjacent ACWL and CCBP. Then, a finite element model of a ballastless track structure was built and a cohesive zone model (CZM) was utilized to model the interface damage initiation, crack propagation, and delamination process under uniform/gradient temperature load. Furthermore, the dynamic response of the ballastless track where CCBP and ACWL were partly/totally debonded was investigated and compared with the perfectly bonded structure. The results demonstrate that bilinear CZM is capable of revealing the interface damage initiation, crack propagation, and delamination process under temperature load. The interface state between the adjacent CCBP and ACWL was greatly affected by temperature changes and the interface bonding state had a great impact on the dynamic response of ballastless track.

scholarly journals Providing interlayer adhesion of dissimilar layers of top road surfaces

2021 ◽  
Vol 274 ◽  
pp. 02003
Author(s):  
Talgat Gabdullin ◽  
Marat Makhmutov
Keyword(s):  
Layer Thickness ◽  
Asphalt Concrete ◽  
Road Construction ◽  
Concrete Mixture ◽  
Cement Concrete ◽  
The Road ◽  
Road Pavement ◽  
Concrete Base ◽  
Pavement Layers ◽  
Asphalt Concrete Pavement

The article reviews the option of how to make the top pavement of asphalt-concrete mixture adhere reliably to the base, which is the underlying cement-concrete coating. The bitumen-latex emulsion is suggested as a binder for the two pavement layers. The research aimed to determine the optimal layer thickness of the bituminous-latex emulsion to be applied and achieve the maximum interlayer adhesion between the top asphalt-concrete pavement and the cement-concrete base. After full-scale experiments, the required layer thickness of the bitumen-latex emulsion was 2 mm. With this layer thickness of the binder, road pavement layers do not delaminate and shear when stressed by the intensive flows of vehicles moving on the roads. The results obtained are important for the road construction industry for suggesting the formulation of bitumen-latex emulsion and finding the most effective layer thickness to be applied. The suggested formulation of a bitumen-latex emulsion is frost-resistant. The article describes the experimental steps for determining the optimal application thickness at a fair length. The maintenance-free life of roads with an asphalt-concrete mixture on a cement-concrete base interlayered with a bitumen-latex emulsion as a binder is assumed to get much longer.

scholarly journals Transverse Cracking of Concrete Base Plate in CRTS III Ballastless Track Structure: Effects of Environmental Boundary Conditions

2021 ◽  
Vol 11 (21) ◽  
pp. 10400
Author(s):  
Weiqiang Guo ◽  
Xin Huang ◽  
Lijun Zhao ◽  
Ya Wei
Keyword(s):  
Numerical Modelling ◽  
Boundary Conditions ◽  
Base Plate ◽  
Test Series ◽  
Railway Track ◽  
Early Age ◽  
Track Structure ◽  
Transverse Cracking ◽  
Ballastless Track ◽  
Concrete Base

The cast-in-place concrete base plate is a main member of the China Railway Track System (CRTS) III ballastless track structure that is prone to generating early transverse cracking. Such cracks can dramatically affect the performance and service life of the railway track structure. This study investigated the influence of temperature and moisture boundary conditions on early cracking behavior of the CRTS III base plate by using approaches of both in situ measurements and numerical modelling. In-site measurements of strain and temperature were made in four test series of CRTS III base plates under the same natural environmental condition but cured with different regimes, and a total of 96 measuring positions were monitored for up to 150 days. The results showed that the strain magnitude and distribution in the field base plate, the initial time at cracking, and the observed cracking pattern varied significantly between the different test series. In order to understand the mechanisms that create these transverse cracks and to provide guidelines for the current curing strategy during construction, the characteristics of temperature-induced and moisture-induced stresses were analyzed by using 3D numerical modelling and by considering early-age concrete creep properties, meteorological factors, and the influence from environmental boundary conditions. The calculated results revealed that early-age transverse cracking in CRTS III base plate depends more on drying shrinkage stress than temperature stress. By conducting this study, we expect to provide guidance for reducing or eliminating early cracks of CRTS III concrete base plate.

scholarly journals Mechanical Characteristics and Failure Mode of Asphalt Concrete for Ballastless Track Substructure Based on In Situ Tests

2020 ◽  
Vol 10 (10) ◽  
pp. 3547
Author(s):  
Qinghong Fu ◽  
Xianhua Chen ◽  
Degou Cai ◽  
Liangwei Lou
Keyword(s):  
Failure Mode ◽  
Asphalt Concrete ◽  
Mechanical Characteristics ◽  
Base Plate ◽  
Ambient Air ◽  
Expansion Joint ◽  
Mechanical Responses ◽  
Ballastless Track ◽  
Track Substructure

Asphalt concrete paved on the surface of a roadbed as a ballastless track substructure has an excellent waterproofing and vibration attenuation performance. However, the mechanical characteristics and the failure mode of this structure under the actions of a cyclic train load and ambient air temperature changes are still unclear. Therefore, a test section of an asphalt concrete substructure was constructed based on a high-speed railway ballastless track project in north China. In situ forced vibration tests and temperature-induced deformation monitoring tests were performed to investigate the mechanical responses of the asphalt concrete, respectively. Test results show that the bottom of the asphalt concrete layer is in the tensile state under the action of the cyclic train load. The surface of the asphalt concrete in contact with the base plate is subjected to tensile stress near the expansion joint under the action of the negative temperature gradient. Changes in the ambient temperature lead to more significant mechanical responses of the asphalt concrete substructure than the cyclic train load, especially near the expansion joint of the base plate. Therefore, the passive tensile failure mode may occur near the expansion joint of the base plate. However, it has also proved that setting isolation layers under the base plate near the expansion joint is an effective method to significantly reduce responses near the expansion joint in this research.

Interface damage and arching mechanism of CRTS II slab track under temperature load

2021 ◽  
Vol 291 ◽  
pp. 123258
Author(s):  
Xuhao Cui ◽  
Bowen Du ◽  
Hong Xiao ◽  
Rui Zhou ◽  
Gaoran Guo ◽  
...  
Keyword(s):  
Slab Track ◽  
Interface Damage ◽  
Temperature Load

Covering and Reinforcement Key Technologies of Airport Old Cement Concrete Pavement

2012 ◽  
Vol 193-194 ◽  
pp. 843-846
Author(s):  
Bao Hua Shi ◽  
Wen Pu Ning ◽  
Han Wei Wang ◽  
Tao Sun
Keyword(s):  
Life Span ◽  
Asphalt Concrete ◽  
Concrete Pavement ◽  
Main Task ◽  
Concrete Pavements ◽  
Cement Concrete ◽  
Treatment Methods ◽  
Key Technologies ◽  
Cement Concrete Pavement

Cement concrete pavements were used in most airports built early in China. Nowadays the main task of airports is how to cover and reinforce damaged pavements. To ensure the life-span of pavement after covering, on the basis of analyzing the treatment methods of original cement concrete pavement, cement and asphalt concrete were used to realize the covering and reinforcement of old cement concrete pavement, and key technologies of Preventing reflective cracks of concrete pavement were put forward, which had a good result in practice

scholarly journals Comparison of Potential Contribution of Typical Pavement Materials to Heat Island Effect

2020 ◽  
Vol 12 (11) ◽  
pp. 4752 ◽  
Author(s):  
Hailu Yang ◽  
Kai Yang ◽  
Yinghao Miao ◽  
Linbing Wang ◽  
Chen Ye
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Potential Contribution ◽  
Heat Island ◽  
Cement Concrete ◽  
Porous Asphalt ◽  
Pavement Materials ◽  
Island Effect ◽  
Urban Heat ◽  
Better Than

Pavement materials have significant influence on the urban heat island effect (UHIE). This paper presents a study on the potential effects of pavement materials on UHIE in a natural environment. Three typical pavement materials, including cement concrete, dense asphalt concrete and porous asphalt mixture, were selected to evaluate their anti-UHIE properties by testing. In this paper, heat island potential (HIP) is proposed as a new index to analyze the influence of pavement materials on UHIE. It is shown that the temperature inside a pavement distinctly depends on the depth, and varies, but is usually higher than the air temperature. Solar radiation in the daytime significantly contributes to the temperature of pavement surface and the upper part. The correlation becomes weak at the middle and the bottom of pavements. Among the three materials tested in this study, the anti-UHIE performance of cement concrete is significantly higher than that of the other asphalt mixtures, while the porous asphalt mixture is slightly better than the dense asphalt concrete in anti-UHIE.

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