PURPOSES : Concrete pavement is excellent in structural performance and durability. However, its functionality – such as noise and skid resistance – is a shortcoming. Functionality such as noise reduction and skid resistance of concrete pavement is affected by the texture surface, and the texture surface is classified according to the length of the wavelength. In recent years, Fine-size exposed aggregate concrete pavement has been applied, which has excellent structural performance and durability, and secures functionalities such as noise reduction and long-term skid resistance by randomly forming texture surface. Fine-size exposed aggregate concrete pavements are constructed by removing the surface cement binder to randomly expose coarse aggregate and their functionality is mainly governed by the surface texture. However, deteriorated concrete by tire-pavement friction and deicing agent may cause abrasion and aggregate loss on the surface texture; thus reducing their functional performances. Abrasion is created by the thin cutoff of aggregate texture under repeated tire-pavement friction. In addition, aggregate loss is defined by the detachment of aggregates from cement binder. This study aims to evaluate the abrasion and aggregate loss of Fine-size exposed aggregate concrete pavement surface texture under tire-pavement friction and scaling tests. METHODS : In the study, abrasion and aggregate loss of tining and exposed aggregate concrete surface treatments were evaluated. Deterioration of each surface treatment was replicated by scaling test under ASTM C 672 test method. Afterward, abrasion test was conducted by ASTM C779 to simulate the tire-pavement friction under traffic. Consequently, abrasion and aggregate loss were measured. RESULTS : Abrasion depth of non-scaling tining, 10-mm EACP, and 8-mm EACP was 1.76, 1.12, and 1.01mm, respectively. Compared to scaling surface treatments, the difference of abrasion depth in tining texture was the largest with value of 0.4mm. For both textures of finesize exposed aggregate concrete, abrasion depth difference was about 0.1mm. Moreover, The 10-mm EACP exhibited a 2.6% of aggregate loss rate caused by tire-pavement friction before conducting concrete deterioration test. After 40-cycle scaling test, aggregate loss increased up to 12.2%. For 8-mm EACP, aggregate loss rate was 1.7% on non-scaling concrete. Further, this rate was magnified up to 7.3% for the 40-cycle scaling concrete. CONCLUSIONS : Under non-scaling or scaling tests, fine-size exposed aggregate concrete pavement showed better abrasion resistance than tining texture since tining was formed by aggregates and cement binder. Additionally, rate of aggregate loss was significant when EACP experienced the deicing agent under numerous cycles of freeze-thaw action.

PURPOSES : This study investigates the abrasion characteristics of coarse aggregate using the Los Angeles (L.A.) abrasion test and the accelerated polishing machine (APM) test. The coarse aggregates are randomly exposed on the surface of asphalt concrete pavements and on exposed aggregate concrete pavements. The exposed aggregates play a very important role in providing skid resistance. Therefore, the adequate abrasion resistance of coarse aggregate must be ensured to maintain the skid resistance during service life. In Korea, the LA abrasion test is conducted according to the KS F 2508 standard for the evaluation of the abrasion resistance of coarse aggregate. However, the road surface abrasion is caused by the friction between the tire and the road surface structure; hence, whether the LA abrasion test, which evaluates the abrasion caused by the impact of coarse aggregates and steel balls, can evaluate the road surface abrasion is questionable. A comparison and an analysis between the APM and LA abrasion tests were conducted herein to evaluate the road abrasion. An analysis was also performed to analyze whether the abrasion characteristics appeared depending on the type of coarse aggregate. METHODS: The results of the APM and LA abrasion tests for various aggregate types were obtained through a series of experiments and literature reviews. The correlation between the LA abrasion loss and the PV data was derived. In addition, the influence of the aggregate type on the abrasion resistance was investigated. RESULTS : An abrasion resistance database was established, and the relationship between the rock types and the abrasion resistance was statistically determined. The results showed that the PV was increased to 0.54 along with a 1% increasing rate of the LA abrasion loss with a 0.67 coefficient of determination. The abrasion resistance was also influenced by the aggregate type, which was found to be statistically significant. CONCLUSIONS: A good relationship between the PV and the LA abrasion loss was obtained, allowing the use of the LA abrasion test (KS F 2508) alone, to reasonably evaluate the abrasion resistance of the exposed aggregate texture. The aggregate types were also found to have an impact on the abrasion resistance.

PURPOSES : Exposed aggregate concrete pavements have been adopted in several countries because of their advantages of pavement texture characteristics, which can produce low tire-pavement noise and higher load-carrying capacities. The magnitude of tire-pavement noise greatly depends on the wavelength of pavement texture. The wavelength of exposed aggregate concrete pavement can be controlled with maximum sizing and by controlling the amount of coarse aggregates in the concrete mixture. In this study, the maximum size and the amount of coarse aggregate in the exposed aggregate concrete pavement are investigated to produce equal levels of wavelength in the asphalt pavement. METHODS: A simple method to measure the average wavelength of pavement texture is introduced. Subsequently, the average wavelength of typical asphalt pavement is investigated. A set of mixture designs of exposed aggregate concrete with three maximum-sized coarse aggregates, and three amounts of coarse aggregate are used. The average wavelengths are measured to find the mixture design needed to produce equal levels of wavelength as typical asphalt pavement. RESULTS : With a cement content of 420 kg/m3 and fine aggregate modulus of 30%, the number of exposed aggregates was 48, and the shortest texture depth provided a wavelength of 4.2 mm. According to the number of exposed aggregates, the exposed aggregate concrete pavement could be rendered low-noise, because its wavelength was similar to that of asphalt pavement ranging from 3.9 to 4.4 mm. CONCLUSIONS : Selection of appropriate maximum sizes and the amount of coarse aggregates for exposed aggregate concrete pavement can produce a wavelength texture closely resembling that of asphalt pavement. Therefore, the noise level of exposed aggregate concrete pavement can be reduced with an appropriate maximum size and the amount of coarse aggregates are employed.