• International Journal of Highway Engineering
• /
• v.18 no.3
• /
• pp.75-86
• /
• 2016

PURPOSES : The purpose of this study is to investigate characteristics of crack spacing and crack width and their relationship in continuously reinforced concrete pavement (CRCP) based on the data obtained from long-term field observations. METHODS : The crack spacings and crack widths are measured periodically over 10 years at two different CRCP sections: one with asphalt bond breaker beneath concrete slab, and the other with bonded lean concrete base beneath concrete slab. The effects of steel ratio, type of underlying layer, terminal treatment method, and seasonal temperature change on the crack characteristics are evaluated by analyzing the measured data. RESULTS : The CRCP with lean concrete base shows smaller crack spacings than those of the CRCP with asphalt bond breaker. As the steel ratio increases, both the crack spacing and crack width tend to decrease. The crack width becomes larger as the crack age increases, but once the crack age is over a certain value the crack width tends to converge. When the terminal anchor lug system is not used and the expansion joints are employed at the terminals, the crack spacings and crack widths increase near the terminal sections. The crack spacing and crack width seem to be proportional each other, but not necessarily linearly, and their relationship is more distinguished in the summer when the crack widths become smaller. CONCLUSIONS : The steel ratio, underlying layer type, terminal treatment method, and seasonal temperature change affect the characteristics of cracks and the crack spacing and crack width are related to each other.

• Computers and Concrete
• /
• v.33 no.4
• /
• pp.445-469
• /
• 2024

The Federal Highway Administration (FHWA) has recommended the use of AASHTOWare Pavement Mechanistic-Empirical Design (PMED) software for Roller-Compacted Concrete (RCC) pavement design, but specific calibration for RCC is missing. This study investigates the software's capacity to predict the long-term performance of RCC roadways within the framework of conventional concrete pavement calibration. By reanalyzing existing RCC projects in several U.S. states: Colorado, Arkansas, South Carolina, Texas, and Illinois, the study highlights the need for specific calibration tailored to the unique characteristics of RCC. Field observations have emphasized occurrence of early distresses in RCC pavements, particularly transverse-cracking and joint-related issues. Despite data challenges, the AASHTOWare PMED software exhibits notable correlation between its long-term predictions and actual field performance in RCC roadways. This study stresses that RCC applications with insufficient joint spacing and thickness are prone to premature cracking. To enhance the accuracy of RCC pavement design, it is essential to discuss the inclusion of RCC as a dedicated rigid pavement option in AASHTOWare PMED. This becomes particularly crucial when the rising popularity of RCC roadways in the U.S. and Canada is considered. Such an inclusion would solidify RCC as a viable third option alongside Jointed Plain Concrete Pavements (JPCP) and Continuously Reinforced Concrete Pavements (CRCP) for design and deployment of rigid pavements. The research presents a roadmap for future calibration endeavors and advocates for the integration of RCC pavement as a distinct pavement type within the software. This approach holds promise for achieving more precise RCC pavement design and performance predictions.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.13 no.1 s.53
• /
• pp.106-114
• /
• 2009

The steel design based on the width of transverse crack which is the major factor to affect a long-term performance of continuously reinforced concrete pavement was developed. For this study, twenty-one cities of Texas were selected and the temperature data was collected at those locations during the past ten years. From the data, zero-stress temperatures were calculated by the PavePro program and the widths of transverse crack were analyzed by the CRCP program. The variables used to this numerical analysis were slab thickness, coefficient of thermal expansion of concrete, steel ratio, and design temperature. The total of 448 factorial runs were made and the regression analysis was performed using the results. Steel ratios from the regression equations were backcalculated and a steel design table was proposed.

• International Journal of Highway Engineering
• /
• v.11 no.2
• /
• pp.121-132
• /
• 2009

Thin bonded continuously reinforced concrete overlay(CRCO) was constructed on He existing jointed plain concrete pavement(HCP) surface at Seo-Hae-Ahn express highway in South Korea in order to evaluate its applicability and performance. Two sections of road were considered for this evaluation. In the first section, the concrete overlayer was placed and cut down to the existing layer to form transverse joints while CRCO was constructed on top of the existing layer in the second section. Early strength concrete(Type III) was utilized for both overlay sections. The depth of milling and the thickness of overlaid layer were 5 cm and 10 cm, respectively. Several vibrating wire gauges(VWG) were installed to evaluate the performance of CRCO with respect to curling, delamination, and crack propagation. As a result of the strength test, it was found that strength of the material reaches the design criteria within 1-3 days. Analysis with vibrating wire gauge(VWG) showed CRCO effectively restricts joint movement. High adhesive strength also was observed from the material regardless of length of aging. Meanwhile, transverse cracks were observed on the middle of the section where JPCP overlay was applied whereas arbitrarily cracks in transverse direction were observed on the section where CRCP was applied.

• 한국도로학회:학술대회논문집
• /
• 2011.03a
• /
• pp.197-200
• /
• 2011

• 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.

• 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.

• International Journal of Highway Engineering
• /
• v.16 no.6
• /
• pp.1-8
• /
• 2014

PURPOSES : Analysis and design of asphalt concrete (AC) and continuously reinforced concrete (CRC) composite pavements. METHODS : In this study, the service life of the AC/CRC composite pavements was determined based on the probabilistic method in the mechanistic-empirical pavement design guide(MEPDG). Typical pavement design was provided with respect to heavy truck traffic volume of highways. RESULTS : The service life of the composite pavements based on IRI was shorter than that based on rutting at lower traffic volume, but this trend was switched at higher traffic volume. CONCLUSIONS : It is concluded that the main distress affecting the service life of the composite pavements was longitudinal roughness and rutting. Roughness became lower, but rut depth became greater as the stiffness of the CRC increased.

• International Journal of Highway Engineering
• /
• v.10 no.4
• /
• pp.9-18
• /
• 2008

Curling is caused by the difference in the temperature and humidity by the depth of the slab in Jointed Plain Concrete Pavement. Slab curvature shape and size change due to curling exert a profound influence on the internal stress and roughness of the pavement, affecting structural and functional performance of the pavement. Direct measurement of the slab curvature entails many problems. Many measuring instruments have to be installed at the early-stage of the pavement construction, and the behavior of the slab curvature needs to be measured accurately from the early-stage. Moreover, the cost and technical difficulty are very formidable to measure the slab curvature. This study develops a measurement method for slab curvature in jointed concrete pavement at any given time by applying Power Spectrum Density Analysis and Inverse Fast Fourier Transformation to the profile data, that can be easily obtained at the construction field site. The effectiveness of this developed method is verified by measuring the profile data of the test road of jointed concrete pavement at an inland central expressway by the hour and by examining the result of extracting the slab curvature shape from this profile data. Additionally, the profile data of CRCP(Continuously Reinforced Concrete Pavement) sections on the same expressway were obtained and analyzed at the same time. The validity of the method developed for the slab curvature shape extraction is verified by comparing the result from the analysis of the profile data of CRCP sections with that from the analysis of the prof1Ie data of jointed concrete pavement sections.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
• /
• v.19 no.3
• /
• pp.43-49
• /
• 2015