Performance of AC overlays using geogrids on PCC contraction joints

Author(s):  
Muhammet Çelik ◽  
Mehmet Tevfik Seferoğlu ◽  
Muhammet Vefa Akpınar
Keyword(s):  
2013 ◽  
Vol 3 (2) ◽  
pp. 111-121
Author(s):  
M. F. Barreda ◽  
M. J. Naber ◽  
I. Quispe Sallo ◽  
J. D. Sota

RESUMENLos cambios volumétricos por variaciones de temperatura y contenido de humedad en el hormigón endurecido de los pavimentos, que por sus restricciones impiden su deformación, causan tensiones de tracción, provocando fisuras aleatorias. La presencia de fisuras de contracción en los pavimentos de hormigón, reducen su vida útil y generan costos de mantenimiento importantes. Es necesario definir a priori la ubicación de las fisuras aserrando el pavimento. Las zonas aserradas crean planos de debilidad donde se forman las fisuras, siendo crítico el momento oportuno para realizar el aserrado de las juntas de contracción en los pavimentos. El período óptimo para efectuar el aserrado se denomina ventana de aserrado. El objetivo de este trabajo es (poner objetivo). Entre los resultados obtenidos se puede decir que (dar resultados). Los estudios son parte de un Proyecto de I+D.Palabras Clave: contracción; hormigón; pavimentos; juntas; fisuras.ABSTRACTIn the hardened concrete of pavements, with limited deformation, volumetric changes due to variations in temperature and humidity cause tensile stresses, with subsequent cracks random. The presence of shrinkage cracks in concrete pavements, reduces its service life and generates substantial maintenance costs. It is necessary to define a priori the location of cracks, by sawing the pavement. Sawn areas create planes of weakness where cracks form, being critical the right time to saw the contraction joints in pavements. The optimal time to perform the sawing is called sawing window. In this paper the first results about concrete pavements are recorded, establishing sawing times, comparing cylindrical compressive strength, maturity of concrete and ultrasonic pulse values. The studies are part of a R & D project.Keywords: contraction; concrete; pavements; joints; cracks.


2021 ◽  
Author(s):  
Muhammad Kashif ◽  
Pieter De Winne ◽  
Muhammad Wisal Khattak ◽  
Amelie Outtier ◽  
Hans De Backer

Continuously reinforced concrete pavement (CRCP) is characterized by the absence of transverse contraction joints and the presence of longitudinal and transverse reinforcement. The continuous longitudinal reinforcement holds the transverse cracks, caused by the longitudinal shrinkage of concrete, tightly together and thus provides long term performance with minimal maintenance cost. Field investigations on recently constructed CRCP's in Flanders region of Belgium indicated horizontal cracking in the vicinity of the longitudinal reinforcement under the transverse cracks which eventually causes the punch-out distress at the edge of the pavement slab. This paper shows the results of a finite element (FE) study to investigate the effect of varying longitudinal reinforcement on the risk of horizontal cracking in CRCP under typical Flanders conditions. For this purpose, a (3D) FE model of CRCP is developed using a FE package Diana 10.2. The varying longitudinal reinforcement with a most narrow spacing of 125mm in the outer region of the pavement slab is applied while keeping the same CRCP reinforcement ratio. A comparison is made with the conventional longitudinal reinforcement spacing (170mm). Development of concrete stress in the vicinity of the longitudinal reinforcement is plotted against the different longitudinal steel spacing. Findings show that the stress in concrete near longitudinal reinforcement is significantly reduced up to maximum 17% when the narrow spacing is used. In addition, the steel stress in the longitudinal reinforcing is reduced up to maximum 31.75% in the outer region of the pavement slab.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shengshan Guo ◽  
Jianxin Liao ◽  
Hailong Huang ◽  
Hui Liang ◽  
Deyu Li ◽  
...  

The contraction joints of arch dams with and without shear keys are simplified to be with no-slip condition and with relative sliding condition, respectively. Based on the Lagrange multiplier method, a contact model considering the manner of independent cantilever dead load type with no-slip condition and relative sliding condition is proposed to model the nonlinearities of vertical contraction joins, which is special to the nonlinear analysis of arch dams considering the manner of dead load type. Different from the conventional Gauss iterative method, the strategy of the alternating iterative solution of normal force and tangential force is employed. The parallelization based on overlapping domain decomposition method (ODDM) and explicit message passing using distributed memory parallel computers is employed to improve the computational efficiency. An existing high arch dam with fine finite element model is analyzed to investigate the effect of shear sliding of vertical joints on seismic response of the arch dam. The result shows that the values of maximum principal tensile stress under relative sliding condition are significantly greater than those under no-slip condition.


Author(s):  
Tatsuo Nishiuchi

To clarify the effects of seismic response of concrete gravity dams under large earthquake, finite element method (FEM) analyses were carried out. In analyses, the height of dam and material properties of concrete and basement rock are same. The 2-dimensional (2D) and the 3-dimensional (3D) FEM model were made and used in earthquake response analyses. The contraction joints between dam block are concerned in 3D non-linear FEM analysis. In the case of same height of dam, the numerical results of damage states and placements in dam are different between 2D FEM model and 3D FEM model, due to the effect of difference in vibration mode of dam. In the 2D FEM model, the damage of top in cross-section becomes remarkable. In the 3D FEM model, the damage of attachment between dam body and basement rock at high-elevation becomes remarkable. The damage of 3D FEM model is smaller than that of 2D FEM model for the same acceleration level of earthquake. The influence of seismic response on contraction joints of 3D non-linear FEM dam model is smaller, which is as same as that of 3D linear FEM dam model. From the above results, the 2D FEM model gives a conservative assessment compared to the 3D FEM model.


Author(s):  
Stephen F. Shober

The general mission of most transportation agencies is to ensure a customer focus in the development and operation of a safe and efficient transportation system. The customers desire comfort, convenience, safety, and cost-effectiveness in a transportation system. Agency research must have the objectives of addressing customer-related issues and measuring benefits of importance to them. Accordingly, any joint and sealant research must answer the questions, Why do we seal? and Is it cost-effective? Joint and sealant studies of portland cement concrete (PCC) pavements must address whether joint sealing enhances total pavement performance and is cost-effective, and, if so, what sealant system should be used. The Wisconsin Department of Transportation (WisDOT) has been studying the effect of PCC joint/crack sealing on total pavement performance for 50 years. By 1967 there was substantial documentation that filling and refilling of contraction joints had no beneficial effect on pavement performance. By 1984, it was concluded that pavements with unsealed joints had better overall performance (distress, ride, materials integrity) than pavements with sealed joints. In 1990, WisDOT passed a policy eliminating all PCC joint sealing, in new construction and maintenance. This "no-seal" policy has saved Wisconsin $6,000,000 annually with no loss in pavement performance and with increased customer safety and convenience. The entire PCC sealing issue is beginning to be addressed at the national level, ensuring no false assumptions and with the customer’s needs in view.


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