• International Journal of Highway Engineering
• /
• v.3 no.2 s.8
• /
• pp.131-140
• /
• 2001

Concrete pavement of Jungbu Expressway composed of CRCP(Continuously Reinforced Concrete Pavement) and JCP(Jointed Concrete Pavement). The CRCP was firstly constructed and applied to new expressway in Korea. It is a good source of the study to analyze the performance of CRCP and JCP because it experiences same amount of traffic and environmental loading. Up to the present, condition survey has conducted several times during 13 years but roughness measurement has not been carefully conducted. Through comparisons among several types of pavement(CRCP, JCP, Asphalt) by roughness, CRCP is superior to JCP. In addition, connected sections in the highway such as bridges and tunnels that have higher IRI values, about 5mm/m, than normal sections should be considered appropriated maintenance such as diamond grinding. The relationship between IRI and distresses carried out by Korea Highway Cooperation in 1999 skewed that the number of crack is related to IRI value in JCP, while other distresses of JCP and CRCP are not shown clearly. The comparison study with IRI values between Jungbu Expressway and GPS-3(JCP) and GPS-5(CRCP) of LTPP data also showed that roughness of Jungbu Expressway is not inferior to that of the state. Some of section showed larger values of IRI are linked with under-9round structures for passages and drainages. The overall performance considering only roughness, the CRCP is also superior to JCP in sections with under-ground tunnels.

• International Journal of Highway Engineering
• /
• v.18 no.1
• /
• pp.73-83
• /
• 2016

PURPOSES : The purpose of this study is to develop a method for improving the accuracy of analysis results obtained from a two-dimensional (2-D) numerical analysis model of continuously reinforced concrete pavement (CRCP). METHODS : The analysis results from the 2-D numerical model of CRCP are compared with those from more rigorous three-dimensional (3-D) models of CRCP, and the relationships between the results are recognized. In addition, the numerical analysis results are compared with the results obtained from field experiments. By performing these comparisons, the calibration factors used for the 2-D CRCP model are determined. RESULTS : The results from the comparisons between 2-D and 3-D CRCP analyses show that with the 2-D CRCP model, concrete stresses can be overestimated significantly, and crack widths can either be underestimated or overestimated by a slight margin depending on the assumption of plane stress or plane strain. The behaviors of crack width in field measurements are comparable to those obtained from the numerical model of CRCP. CONCLUSIONS : The accuracy of analysis results from the 2-D CRCP model can be improved significantly by applying calibration factors obtained from comparisons with 3-D analyses and field experiments.

• International Journal of Highway Engineering
• /
• v.9 no.2 s.32
• /
• pp.39-49
• /
• 2007

The objective of this study was to investigate features of transverse crack occurrence and propagation in continuously reinforced concrete pavement(CRCP) when subjected to environmental loading. The finite element model of CRCP was developed and the element removal method was implemented to predict the crack propagation process. To investigate the effect of the type of environmental loading on the CRCP behavior and cracking aspects, the following three different cases were considered: (1) the temperature gradient between top and bottom of the slab does not vary and the constant temperature drop throughout the depth occurs; (2) the temperature at the slab bottom does not vary and the temperature gradient increases; and (3) the temperature between the mid-depth and the bottom of the slab is the same and does not vary and the temperature at the top decreases. The analysis results showed that the crack occurrence and propagation through the depth of the slab in CRCP were significantly affected by the type of environmental loading. The changes in stress distribution and displacements during the crack occurrence and propagation process could also be investigated.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05a
• /
• pp.58-61
• /
• 2006

The effect of the steel ratio on the behavior of continuously reinforced concrete pavement (CRCP) under moving wheel loads and environmental loads were investigated in this study. The CRCP sections having different steel ratios of 0.6, 0.7, and 0.8% were considered: (1) to evaluate the load transfer efficiency (LTE) at transverse cracks; (2) to investigate strains in CRCP when the system is subjected to moving vehicle loads; (3) and to investigate the time histories of the crack spacing variations. The LTEs were obtained by conducting the falling weight deflectometer (FWD) tests. The strains in the concrete slab and the bond braker layer under moving vehicle loads were obtained using embedded strain gages. The results of this study show that the LTEs at transverse cracks are very high and not affected by the steel ratio. The strains in CRCP under vehicle loads become smaller as the vehicle speed increases or as the wandering distance increases; however, the strains are not clearly affected by the steel ratio. However, the changes in the crack spacings are affected by the steel ratio.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1991.04a
• /
• pp.68-71
• /
• 1991

In this study, to make a construction strategy to minimize or protect punchout and steel corrosion in CRCP, the following items have been studied; 1) Review of the structural response characteristics and the current design criteria in CRCP. 2) Evaluation of basic analytical concepts and the limit of application in the current models 3) Some suggestions of performance monitoring in CRCP and evaluation of construction s-trategy with preformed crack induces.

• 한국도로학회:학술대회논문집
• /
• 2006.10a
• /
• pp.157-164
• /
• 2006

• 한국도로학회:학술대회논문집
• /
• 2009.11a
• /
• pp.387-390
• /
• 2009

• International Journal of Highway Engineering
• /
• v.16 no.6
• /
• pp.95-104
• /
• 2014

PURPOSES : The purpose of this study is to evaluate the degree of restraint (DOR) of longitudinal steel at continuously reinforced concrete pavement (CRCP) against environmental loadings. METHODS : To measure the longitudinal steel strain, 3-electrical resistance and self-temperature compensation gauges were installed to CRCP test section (thickness = 250mm, steel ratio = 0.7%) and continuously measured 10 min. intervals during 259 days. In order to properly analyze the steel strains first, temperature compensation process has been conducted. Secondly, measured steel strains were divided into 12 phases with different events such as before paving, during concrete hardening, and after first cracking, etc. RESULTS : Thermal strain rate (TSR) concept is defined as the linear strain variations with temperature changes and restraints rate of longitudinal steel against environmental loadings (especially thermal loading) with different cases is defined as degree of restraint(DOR). New concept of DOR could be indirect indicator of crack width behaviors of CRCP. CONCLUSIONS : Before paving, DOR of longitudinal steel is almost same at the coefficient of thermal expansion of steel ($12.44m/m/^{\circ}C$) because of no restraint boundary condition. After concrete pouring, DOR is gradually changed into -1 due to concrete stiffness developing with hydration. After first cracking at crack induced area, values of DOR are around -3~-5. The negative DOR stands for the crack width behavior instead of steel strain behavior. During winter season, DOR reached to -5.77 as the highest, but spring this values gradually reduced as -1.7 as the lowest. Based on this observation, we can presume crack width decreased over time within the time frame of this study. This finding is not consistent with the current theory on crack width variations over time, so further study is necessary to identify the causes of crack width reducing. One of the reasons could be related to concrete stress re-distribution and stress relaxation.

• International Journal of Highway Engineering
• /
• v.13 no.4
• /
• pp.81-91
• /
• 2011

This study was conducted to evaluate the necessity of the anchor lug system in continuously reinforced concrete pavement(CRCP) by comparing longitudinal displacements of CRCPs with and without anchor lugs, and to investigate the effect of horizontal cracking on CRCP performance by measuring the vertical displacements. The measurements before and after the anchor lug section was separated were conducted for 12 days in June, and for 14 days in August after the abrupt displacements according to cutting disappeared, respectively. This short term measurement results showed that when anchor lugs were installed, a daily displacement variation at any location was less than 0.1mm; therefore, longitudinal movements were negligibly small. When there were no anchor lugs, longitudinal displacements mainly occurred near the free end and the displacement variation was small; therefore, an expansion joint system seems to be employed at a CRCP terminus without installing anchor lugs. However, further studies are needed to verify the terminus behavior due to annual temperature changes. The horizontal crack width variation was ignorable and did not affect the vertical displacement of the slab. Therefore, the horizontal crack did not delaminate the slab and did not seem to reduce the structural capacity and performance of CRCP.

• 한국도로학회:학술대회논문집
• /
• 2006.10a
• /
• pp.153-156
• /
• 2006