scholarly journals Optimization of parameters affecting horizontal cracking in continuously reinforced concrete pavement (CRCP)

2019 ◽  
Vol 46 (7) ◽  
pp. 634-642 ◽  
Author(s):  
Kukjoo Kim ◽  
Sangyoung Han ◽  
Mang Tia ◽  
James Greene
Keyword(s):  
Reinforced Concrete ◽  
Coefficient Of Thermal Expansion ◽  
Field Evaluation ◽  
Concrete Pavement ◽  
Slab Thickness ◽  
Tensile Stresses ◽  
Cracking Potential ◽  
Performance Problem ◽  
D Model ◽  
Steel Design

Field evaluation of distresses in continuously reinforced concrete pavement (CRCP) indicated punch-out distress associated with horizontal cracking at the depth of the longitudinal steel is the most severe performance problem in CRCP. The developed 3-D model was used to perform a parametric analysis to determine the effects of critical loading location, concrete properties, and longitudinal steel design on horizontal cracking potential. The maximum vertical tensile stresses in the concrete were slightly affected by the coefficient of thermal expansion of the concrete. The critical tensile stresses in the concrete were observed to decrease as the base modulus, slab–base friction, slab thickness, and transverse crack spacing increase. The vertical tensile stresses significantly decreased when the longitudinal steel spacing decreased. The use of varying longitudinal steel spacing and reducing the depth of steel may be one of the ways to reduce the horizontal cracking potential without changing the steel ratio of the slab.

scholarly journals Finite Element Simulation and Multi-Factor Stress Prediction Model for Cement Concrete Pavement Considering Void under Slab

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5294
Author(s):  
Bangyi Liu ◽  
Yang Zhou ◽  
Linhao Gu ◽  
Xiaoming Huang
Keyword(s):  
Finite Element ◽  
Tensile Stress ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Mesh Size ◽  
Maximum Tensile Stress ◽  
Concrete Pavement ◽  
Slab Thickness ◽  
Void Size ◽  
Tensile Stresses

Uneven support as result of voids beneath concrete slabs can lead to high tensile stresses at the corner of the slab and eventually cause many forms of damage, such as cracking or faulting. Three-dimensional (3D) finite element models of the concrete pavement with void are presented. Mesh convergence analysis was used to determine the element type and mesh size in the model. The accuracy of the model is verified by comparing with the calculation results of the code design standards in China. The reliability of the model is verified by field measurement. The analysis shows that the stresses are more affected at the corner of the slab than at the edge. Impact of void size and void depth at the slab corner on the slab stress are similar, which result in the change of the position of the maximum tensile stress. The maximum tensile stresses do not increase with the increase in the void size for relatively small void size. The maximum tensile stress increases rapidly with the enlargement in the void size when the size is ≥0.4 m. The increments of maximum tensile stress can reach 183.7% when the void size is 1.0 m. The increase in slab thickness can effectively reduce maximum tensile stress. A function is established to calculate the maximum tensile stress of the concrete slab. The function takes into account the void size, the slab thickness and the vehicle load. The reliability of the function was verified by comparing the error between the calculated and simulated results.

Probabilistic Analysis of Highway Pavement Life for Illinois

2003 ◽  
Vol 1823 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Nasir G. Gharaibeh ◽  
Michael I. Darter
Keyword(s):  
Reinforced Concrete ◽  
Probabilistic Analysis ◽  
Asphalt Concrete ◽  
Geographic Location ◽  
Concrete Pavement ◽  
Pavement Management ◽  
Slab Thickness ◽  
Probability Of Survival ◽  
Load Carrying ◽  
The Impact

The Illinois Department of Transportation has periodically conducted pavement longevity studies to assess the longevities and the traffic loadcarrying capacities of these new and rehabilitated pavements so that any needed improvements to design, construction, or rehabilitation could be identified and implemented in a timely manner. The results of the latest round of pavement longevity studies in Illinois provide performance data updated through 2000 for new hot-mix asphalt concrete (HMAC), jointed reinforced concrete pavement (JRCP), and continuously reinforced concrete pavement (CRCP) construction as well as the asphalt concrete (AC) overlays (first, second, and third overlays) of these original pavements. These studies were conducted on more than 2,000 centerline miles of Interstate and other freeways that were constructed beginning in the 1950s in Illinois. Significant findings on the performance of the original pavements and overlays were obtained, and these findings will be of value to designers and managers to improve pavement cost-effectiveness and life. Survival curves have an economic impact on the agency. Key findings show the impact of pavement type (HMAC, JRCP, or CRCP), slab thickness, geographic location (north or south), durability cracking (D-cracking), and AC overlay thickness (coupled with preoverlay condition) on longevity and load-carrying capacity. The results of the probabilistic analysis illustrate the wide variation in pavement life and traffic carried. The study also provides models for predicting the probability of survival for various designs of original pavements and AC overlays in Illinois for use in pavement management.

Spalling in Continuously Reinforced Concrete Pavement in Texas

2020 ◽  
Vol 2674 (11) ◽  
pp. 731-740
Author(s):  
Pangil Choi ◽  
Lochana Poudyal ◽  
Fouzieh Rouzmehr ◽  
Moon Won
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Coefficient Of Thermal Expansion ◽  
Field Testing ◽  
Concrete Pavement ◽  
Materials Testing ◽  
Finite Element Program ◽  
Texas Department ◽  
Conducting Materials ◽  
Element Program

The performance of continuously reinforced concrete pavement (CRCP) in Texas has been quite satisfactory, primarily thanks to the continuous improvements in design and construction. However, severe spalling has been a major problem, and the Texas Department of Transportation (TxDOT) has sponsored several research projects since 1985 to identify solutions for this serious problem. Even though the research efforts were successful in identifying spalling mechanisms, developing a policy that TxDOT could easily implement has been a challenge. To develop a more practical solution to this problem, TxDOT initiated a research study, and the research efforts consisting of identifying CRCP projects with severe and no spalling, obtaining and conducting materials testing on concrete cores from those projects, analyzing the testing data, and performing theoretical analyses to validate the testing results. Among the material properties evaluated, the coefficient of thermal expansion (CTE) of concrete proved to have the best correlation with spalling. Detailed analyses of mechanistic behavior of concrete conducted with an object-oriented finite element program (OOF2) and commercial finite element program verified the reasonableness of the field-testing results. All concrete cores from CRCP with severe spalling had a CTE larger than 5.5 microstrains/°F, whereas no spalling was observed in concrete with a CTE less than that value. Based on this finding, TxDOT now requires the use of coarse aggregate that will produce concrete with a CTE of less than 5.5 microstrains/°F for CRCP construction. It is expected that this implementation will reduce the spalling in CRCP substantially.

scholarly journals Finite element simulation and multi-factor stress prediction model for cement concrete pavement considering void under slab

2021 ◽  
Author(s):  
Liu Bangyi ◽  
Huang Xiaoming
Keyword(s):  
Finite Element ◽  
Tensile Stress ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Maximum Tensile Stress ◽  
Concrete Pavement ◽  
Slab Thickness ◽  
Void Size ◽  
Tensile Stresses ◽  
The Impact

Uneven support as result of voids beneath concrete slabs can lead to high tensile stresses at the corner of the slab and eventually cause many forms of damage, such as cracking or faulting. Three-dimensional (3D) finite element models of the concrete pavement with void are presented. The accuracy of the model is verified by two methods. The analysis shows that the impact of void size and void depth at the slab corner on the slab stress are similar, which result in the change of the position of the maximum tensile stress. The maximum tensile stresses do not increase with the increase of the void size for relatively small void size. The maximum tensile stress increases rapidly with the enlargement in the void size when the size≥0.4m. The increments of maximum tensile stress can reach 183.7% when the void size are 1.0m. The increase of slab thickness can effectively reduce maximum tensile stress. A function is established to calculate the maximum tensile stress of the concrete slab. The function takes into account the void size and the slab thickness. The reliability of the function was verified by comparing the error between the calculated and simulated results.

Improved Backcalculation Procedure for Continuously Reinforced Concrete Pavement

2018 ◽  
Vol 2672 (40) ◽  
pp. 336-347 ◽  
Author(s):  
Yating Zhang ◽  
Jeffery Roesler
Keyword(s):  
Reinforced Concrete ◽  
Load Transfer ◽  
Soil Layer ◽  
Concrete Pavement ◽  
Crack Spacing ◽  
Interface Condition ◽  
Slab Thickness ◽  
Transverse Cracks ◽  
Element Analysis ◽  
K Value

Falling weight deflectometer (FWD) testing is effective in evaluating the structural response of in-situ concrete pavements through the backcalculated pavement layer parameters. Specifically, the FWD data can be used to backcalculate the foundation layer and concrete stiffness or the soil layer stiffness, effective slab thickness, and slab–base interface condition. Since continuously reinforced concrete pavement (CRCP) has closely spaced transverse cracks, the traditional backcalculation assumption of an infinite slab can lead to significant errors in the backcalculated results. In this paper, solutions for backcalculated modulus of subgrade reaction ( k-value), elastic modulus of concrete ( E), and effective thickness ( heff) for different crack spacing have been derived from 2-D finite element analysis. AASHTO sensor configuration (0, 12, 24, 36 in.) was recommended for CRCP with crack spacing ≥6 ft, and an alternative solution for crack spacing of 4 and 5 ft was proposed with AREA24. Crack load transfer efficiency (LTE) across transverse cracks had limited impact on backcalculated results if the LTE was >80%. As expected, the backcalulation values were sensitive to the load plate’s longitudinal position relative to the transverse crack especially for crack spacings smaller than 8 ft. The proposed backcalculation method was applied to a field CRCP test section with different crack spacing, reinforcement ratio, and base types.

Numerical evaluation of horizontal cracking potential in continuously reinforced concrete pavement under varying saw-cut depths

2021 ◽  
Author(s):  
Muhammad Kashif ◽  
Amelie Outtier ◽  
Muhammad Wisal Khattak ◽  
Pieter De Winne ◽  
Hans De Backer
Keyword(s):  
Reinforced Concrete ◽  
Tensile Stress ◽  
Transverse Crack ◽  
Flow Analysis ◽  
Field Trials ◽  
Concrete Pavement ◽  
Early Age ◽  
Fe Model ◽  
Cracking Potential ◽  
Steel Bar

<p>The objective of this study is to evaluate the horizontal cracking potential in terms of vertical tensile stress development near longitudinal steel bar in the continuously reinforced concrete pavement (CRCP). For this purpose, a three-dimensional (3D) finite element (FE) model of the CRCP segment with partial surface saw-cuts has been developed using the FE tool Diana 10.3. The early-age behaviour of CRCP subjected to external varying temperature field condition has been evaluated by using the staggered structural-flow analysis. The characteristics of the early-age crack pattern in terms of crack initiation and crack propagation obtained from the FE model are compared with the field observations of cracking developments on the CRCP sections in Belgium. The FE results indicate that the vertical tensile stress in concrete near the longitudinal steel bar develops at the transverse crack interface. It translates that the horizontal crack perpendicular to the vertical concrete stress can initiate from the transverse crack depending on the magnitude of stress against developing concrete tensile strength. It has also been observed that the deeper the saw-cut, the larger the magnitude of vertical tensile stress and the higher incident of horizontal cracking. Moreover, the developed 3D FE model can be further used to optimize the early-age behaviour of CRCP in advance of costly field trials.</p>

Early Age Performance of Continuously Reinforced Concrete Pavement with Different Types of Aggregate

1997 ◽  
Vol 1568 (1) ◽  
pp. 35-43
Author(s):  
Yoon-Ho Cho ◽  
Terry Dossey ◽  
B. Frank Mccullough
Keyword(s):  
Reinforced Concrete ◽  
Field Test ◽  
Field Tests ◽  
Concrete Pavement ◽  
Crack Spacing ◽  
Winter Period ◽  
Thermal Coefficient ◽  
Curing Methods ◽  
Pavement Construction ◽  
New Variables

The effect of coarse aggregate on pavement performance has been attributed to the volume of aggregate used in pavement construction. The different patterns of crack development for limestone (LS) and siliceous river gravel (SRG) are a typical example of aggregate-induced variable performance in continuously reinforced concrete pavement (CRCP). An attempt was made to find a reasonable solution for pavements with SRG. As a way to solve the performance problem observed from the SRG pavement, a blended aggregates mixture was suggested. Laboratory and field tests were performed to check the feasibility of their application in pavements. From the laboratory test, a 50:50 blending ratio was suggested after considering the effect on tensile strength and thermal coefficient of expansion. Field test sections were also constructed to verify previous performance observations for the two aggregates and to provide performance data for new variables such as blended aggregates and special curing methods. Unexpectedly, the blended mixture did not improve the performance of SRG pavement; rather it experienced worse cracking than SRG alone. A controlled experiment with additional field test sections is needed to verify or disprove this finding. The only definitive finding was that selection of aggregate in the concrete pavement is a vital consideration for the design of the pavement. The CRCP8 analytical program reasonably predicted crack spacing for both SRG and LS pavements, predicting mean crack spacing of 0.99 m (3.25 ft) for SRG and 1.98 m (6.41 ft) for the limestone. These values are somewhat below the actual spacing observed at 100 days. Data collected after the first winter period will be required to calibrate the program.

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