Numerical Modeling of Continuously Reinforced Concrete Pavement Subjected to Environmental Loads

Author(s):  
Seong-Min Kim ◽  
Mooncheol Won ◽  
B. Frank McCullough

Continuously reinforced concrete pavement (CRCP) performance depends on, among other factors, the characteristics of early developing cracks caused by environmental loads. The primary objective is to evaluate effects of design, materials, and construction variables on the characteristics of cracks in CRCP when subjected to environmental loads. A mechanistic model is developed using finite element formulations. Concrete and longitudinal steel are discretized using the plane strain and the frame elements, respectively. Various bond stress and slip models between concrete and longitudinal steel and between concrete and the underlying layers are developed using the spring elements. The creep effect is also included using the effective modulus method. CRCP responses from the model vary depending on the concrete and steel bond-slip models. An accurate bond-slip model needs to be investigated further by experiments to increase the accuracy of the mechanistic model. Concrete creep has beneficial effects on CRCP responses. The thermal coefficient of concrete has significant effects on CRCP responses. Using concrete with a low thermal coefficient will improve CRCP performance. Longitudinal steel variables—the amount of steel, bar diameter, and steel location—are important design variables that influence CRCP behavior. For given environmental conditions, an optimum steel design can be developed using the model developed.

Author(s):  
Yoon-Ho Cho ◽  
Terry Dossey ◽  
B. Frank Mccullough

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.


2021 ◽  
Vol 11 (4) ◽  
pp. 1659
Author(s):  
Muhammad Kashif ◽  
Ahsan Naseem ◽  
Nouman Iqbal ◽  
Pieter De Winne ◽  
Hans De Backer

The technological innovation of continuously reinforced concrete pavement (CRCP) that contains a significantly reduced amount of reinforcement and the same fundamental behavior as CRCP is called advanced reinforced concrete pavement (ARCP). This new concept of a rigid pavement structure is developed to eliminate unnecessary continuous longitudinal steel bars of CRCP by using partial length steel bars at predetermined crack locations. In Belgium, partial surface saw-cuts are used as the most effective crack induction method to eliminate the randomness in early-age crack patterns by inducing cracks at the predetermined locations of CRCP. The reinforcement layout of ARCP is designed based on the distribution of steel stress in continuous longitudinal steel bar in CRCP and the effectiveness of partial surface saw-cuts as a crack induction method. The 3D finite element (FE) model is developed to evaluate the behavior of ARCP with partial surface saw-cuts. The early-age crack characteristics in terms of crack initiation and crack propagation obtained from the FE simulation are validated with the field observations of cracking characteristics of the CRCP sections in Belgium. The finding indicates that there is fundamentally no difference in the steel stress distribution in the partial length steel bar of ARCP and continuous steel bar of CRCP. Moreover, ARCP exhibits the same cracking characteristics as CRCP even with a significantly reduced amount of continuous reinforcement.


2021 ◽  
Author(s):  
Norinobu Katayama ◽  
Kazuhiko Fujisaki ◽  
Takehisa Ueno ◽  
Ryutaro Onishi ◽  
Isamu Yoshitake

The decline in the number of persons of working age is a social problem in Japan. This is a particularly serious concern for workers in the construction field; construction systems should be considered for productivity improvements. Prefabrication systems are an effective method for shortening construction cycles and times. In fact, various precast concrete members have been employed to realize more rapid construction and improvements in quality. Using precast concrete members is difficult because jointless roads are preferable for highway pavement. Continuously reinforced concrete pavement (CRCP), which has the advantages of concrete jointless construction and high ductility, is a suitable method for highway road construction. Typical Japanese highways built with CRCP reduce the amount of horizontal cracking by arranging transverse rebars at an angle of 60° to the main rebars. Note that rebar placement and bonding in conventional CRCP are troublesome and labor intensive owing to the long construction time required. We have developed prefabricated steel bar meshes for CRCP and can report some benefits relating to their practical application. To examine the fundamental properties of mesh panels, we conducted a laboratory experiment and a simulated field test. The primary concern of welded rebars are failures induced by cyclic loading. A flexural fatigue loading test using CRCP models was conducted. In addition, a comparative survey on conventional and prefabrication systems was performed in the simulated field test to quantify the constructability of CRCP and to observe the extent of cracking in concrete. This paper reports on our experimental investigation.


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

<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>


Author(s):  
Katarzyna Zdanowicz ◽  
Boso Schmidt ◽  
Hubert Naraniecki ◽  
Steffen Marx

<p>The bond behaviour of concrete specimens with carbon textile reinforcement was investigated in the presented research programme. Pull-out specimens were cast from self-compacting concrete with expansive admixtures and in this way chemical prestress was introduced. The aim of the research was to compare bond behaviour between prestressed specimens and non-prestressed control specimens. During pull-out tests, the pull-out force and notch opening were measured with a load cell and laser sensors. Further, bond - slip and pull-out force - crack width relationships were drawn and compared for prestressed and non-prestressed specimens. Chemically prestressed specimens reached 24% higher bond strength than non-prestressed ones. It can be therefore concluded, that chemical prestressing positively influences the bond behaviour of concrete with textile reinforcement and thus better utilisation of its properties can be provided.</p>


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