In response to the contemporary demands of the construction industry for climate-change action and carbon neutrality, this study conducts a comprehensive analysis of the applicability of Portland limestone cement (PLC)—a notable sustainable alternative to ordinary Portland cement (OPC)—for highway pavement applications. PLC is an eco-friendly material that reduces carbon-dioxide emissions and energy consumption compared with OPC by reducing the clinker ratio in its manufacturing process. This study examines the fundamental physical and chemical mechanisms of PLC concrete and compares its mechanical performance and durability characteristics with those of OPC concrete. The results indicate that PLC concrete exhibits performance levels equivalent to or superior to those of OPC in key metrics such as compressive and flexural strengths, with particularly outstanding performance in durability aspects such as chloride-penetration resistance. However, the potential for early-age cracking and compatibility issues with certain admixtures are identified as challenges that must be addressed for the wider field application of PLC concrete. Thus, this study proposes the integration of nanotechnology to overcome these technical limitations and maximize performance. Specifically, methods to significantly improve the strength, abrasion resistance, fatigue resistance, and crack-control performance by utilizing nanomaterials such as Nano- , Nano- , and graphene oxide ( ) to control the microstructure of PLC concrete are presented. Finally, a comprehensive roadmap is proposed to enhance the field applicability of PLC concrete for highway pavements and contribute to the construction of sustainable social infrastructure through three key strategies: mix design optimization, consideration of regional environmental conditions, and integration of nanotechnology.

The objective of this study is to quantitatively evaluate the effect of pavement aging on the blow-up occurrence temperature of jointed concrete pavements. Pavement aging reduces the effective joint width through joint deterioration and infiltration of incompressible materials, thus decreasing the trigger temperature for pavement growth (TTPG). The TTPG is defined as the concrete temperature at which all transverse contraction joints within the expansion joint system are completely closed and the slabs begin to behave as a single structural unit. Once the maximum concrete temperature (Tmax) exceeds the TTPG, the temperature difference (ΔT = Tmax−TTPG, i.e., the effective temperature) results in compressive stresses within the slab, thus initiating the blow-up mechanism. A lower TTPG increases ΔT, thus accelerating thermal expansion and the accumulation of the annual maximum compressive stress. Expansive products generated by the alkali-silica reaction (ASR) and higher coefficients of thermal expansion (CTEs) further intensify internal compressive stresses, thus inducing blow-up at lower temperatures. Moreover, the subbase type affects the blow-up occurrence temperature owing to the differences in geometric imperfections and the slab–subbase friction. This study employs the pavement growth and blow-up analysis model to estimate blow-up occurrence temperatures, thus explicitly addressing the combined effect of pavement aging, ASR, CTE, and subbase type.

Pavement friction under wet conditions is a critical factor affecting driving safety and is determined significantly by water-film thickness (WFT). Although current road geometric design standards incorporate wet-pavement friction coefficients as design parameters, they do not adequately account for the effects of WFT. This study estimates the variation in the coefficient of friction caused by changes in the WFT and applies the results to the calculation of stopping sight distance (SSD) and radius of curvature (RC), which are essential elements in road geometry design. Through this approach, the study identifies the limitations of current standards and proposes potential improvements. WFT was estimated using the Gallaway model, which was previously verified through comparative analysis and experimental validation. The model incorporates key influencing factors such as rainfall intensity, pavement slope, drainage path length, and mean texture depth. Based on the estimated WFT, the longitudinal and lateral friction coefficients were calculated using Gallaway’s SN and Lamm’s models, respectively. Using these friction values, the SSD and RC were evaluated under various pavement and environmental conditions. Furthermore, comparisons with existing design guidelines were performed to assess whether the predicted values satisfy the standards under different conditions. Additionally, areas requiring improvement were identified. The analysis confirmed that WFT increases with rainfall intensity and drainage path length, whereas it decreases as the pavement slope, mean texture depth, and tread depth increase. An increase in the WFT significantly reduces the friction coefficient, which consequently increases the SSD and required RC. In particular, under conditions such as heavy rainfall, worn treads, long drainage paths, and shallow surface textures, the calculated SSD and RC typically exceed the minimum requirements of current road-design standards. By contrast, ensuring sufficient surface texture effectively maintains friction performance and mitigates increases in the SSD and RC. The findings of this study suggest that current road-design standards—based on dry or vaguely defined wet conditions—may not sufficiently address the effects of WFT on pavement friction. A quantitative, WFT-based approach is required for more realistic friction estimations. To enhance safety in rainy conditions, road designs should incorporate structural and material improvements, such as optimizing pavement slopes, reducing the drainage path length, maintaining adequate surface texture and tread depth, and adopting high-performance surfacing materials. Additionally, dynamic speed-management systems during rainfall and preventive maintenance for sections with inferior drainage should be considered to improve driving safety under wet weather conditions.

This study analyzes the impact of climate change on the performance of continuous reinforced concrete pavement (CRCP) and proposes a method to improve the existing KPRP–CRCP design procedure. Our analysis of monthly mean temperature data from the Seoul Meteorological Station revealed a general increase in temperature from 2001 to 2034, with a more significant increase observed during summer and winter. The existing KPRP–CRCP design method uses the drop temperature (DT) as a key variable. Notably, the increasing monthly mean temperatures owing to climate change tend to decrease the DT that in turn lowers the maximum stress on the pavement slab. This leads to a significant problem: if the traditional design method based on outdated data is used, the predicted number of punchouts will be lower than expected. This can result in an over-reduction in the reinforcement ratio and slab thickness, leading to premature failure and increased maintenance costs. To solve this issue, we introduced a predictive model for the final setting temperature that accounts for monthly and regional characteristics. Applying this model showed that as the temperature increased, the DT and maximum stress proportionally increased. This provided a more realistic prediction of the number of punchouts and addressed the flaws of the existing design method. Furthermore, our analysis of punchout counts based on the construction start month using this predictive model revealed that punchouts were more frequent in summer (July–August) and less frequent in winter (January–February). Based on this, we determined that the optimal seasons for placing continuous reinforced concrete pavements were spring (March–June) and fall (September–November). In situations where the actual construction start month was unknown, we recommended using a conservative design approach based on the design in August, when punchouts were most likely to occur.

Wet pavement friction decreases with an increase in water film thickness (WFT), leading to a significant increase in vehicle crashes. The British pendulum test described in ASTM E303-93 is a method used to measure the pavement friction under wet conditions for the input of geometric design and pavement management systems. The British pendulum number (BPN) under wet conditions varies with WFT. Following the ASTM E303-93 standard procedure, WFT was simulated by spraying water onto the pavement surface. However, the measurement of the BPN did not include specific information regarding the WFT present during testing. To address these issues, WFTs and BPNs are measured using artificial rainfall generated by a rainfall simulator across various intensities, drainage lengths, pavement slopes, and pavement surfaces. This study aims to investigate the influence of the WFT on the BPN for wet pavement friction and provide the WFT corresponding to each BPN measurement for different surface types. The BPNs and WFTs of three test slabs, including diamond grooving and tining surfaces with 16 mm and 25 mm spacing, were measured under wet conditions by spraying water and creating WFTs using a rainfall simulator. Measurements were taken in both longitudinal and transverse directions, considering different rainfall intensities (40 mm/h, 80 mm/h, and 130 mm/h), pavement slopes (2%, 5%, and 10%), and drainage path lengths (1 m, 2 m, 3 m, 4 m, and 5 m). The test results indicated that wet pavement friction decreased as the WFT increased that was influenced by several factors including the pavement slope, mean texture depth, rainfall intensity, and drainage path length. Specifically, the WFT tended to increase with a decrease in the pavement slope and an increase in the mean texture depth, rainfall intensity, and drainage path length. In particular, surface texture played a significant role in the wet friction performance, with diamond-grooved pavements. Among the tested surfaces, the diamond-grooved (longitudinal and transverse) pavements demonstrated a more effective wet friction performance, maintaining higher BPN values across varying WFT levels. Conversely, longitudinally and transversely tined surfaces with 25 mm spacing showed a more significant decrease in BPN, reflecting a higher sensitivity to WFT. In contrast, tined surfaces with 16-mm spacing exhibited a more gradual reduction in friction, likely owing to enhanced drainage and better resistance to water-induced friction loss. Additionally, these results indicated that longitudinal textures demonstrated a more significant reduction in friction with increasing WFT compared with transverse textures. This demonstrated that the texture type, direction, and spacing significantly influenced the friction loss under wet conditions, with diamond grooving offering the best overall performance. This study highlighted the critical role of WFT in pavement friction design, emphasizing the need to consider the WFT for a more accurate assessment of wet pavement friction. The WFT was influenced by factors such as the pavement slope, rainfall intensity, drainage path length, and surface texture. The diamond-grooved pavements demonstrated a more effective wet friction performance, maintaining higher BPN values across varying WFT levels. In contrast, tined surfaces with larger spacings exhibited more significant friction loss, whereas those with smaller spacings showed a more gradual reduction, likely owing to better drainage. In particular, longitudinal textures showed a greater reduction in friction compared with transverse textures. Overall, the texture type, direction, and spacing played crucial roles in wet friction performance, with diamond grooving offering the best results.

Blow-up in jointed concrete pavements refers to a type of distress caused by the excessive accumulation of compressive stress within concrete slabs, primarily resulting from internal expansion and elevated environmental temperatures. This phenomenon frequently leads to slab buckling and is challenging to predict in terms of both timing and location, thereby significantly threatening the long-term structural stability of the pavement. In the present study, the pavement growth and blow-up analysis (PGBA) model was employed to quantitatively predict the timing of blow-up events in jointed concrete pavements. The model estimates the maximum compressive stress within the slab throughout the pavement’s service life using input parameters such as reliability, climatic conditions, pavement structure, material properties, and expansion joint configurations. Subsequently, the model compares the estimated stress to the threshold stress associated with blow-up to determine the likely time of occurrence. A sensitivity analysis was performed on a range of design and environmental factors, including annual maximum temperature, annual maximum precipitation, coefficient of thermal expansion, ASR, pavement thickness, geometric imperfection, and expansion joint spacing and width. The influence of each factor on the predicted blow-up occurrence time was quantitatively evaluated. The analysis demonstrated that climatic conditions, pavement structure, material properties, and expansion joint characteristics, as considered in the PGBA model, collectively govern the timing of blow-up events. These findings offer critical insights for informing the design and maintenance strategies of jointed concrete pavements.

국내 도심지에 적용하고 있는 중앙버스정류장의 포장은 주로 아스팔트 포장으로 시공되어 있으나 중차량인 버스의 하 중으로 인해 포장 파손 사례가 증가하여 시민들의 안전에 악영향을 미치고 있으며 유지보수 비용이 매년 증가하고 있다. 서울시에서는 이러한 문제를 해결하기 위해 국내 최초로 중앙버스정류장 신설 구간에 현장타설 방식으로 연속철근 콘크 리트 포장(CRCP)을 시공하였다. 본 연구에서는 이러한 구간의 연속철근 콘크리트 포장에 대한 이동차량 하중에 의한 동 적 거동 특성을 분석하고자 포장 슬래브에 콘크리트 변형률계를 설치하고 덤프트럭을 통과시키며 동적 하중 재하 실험 을 수행하였다. 실험에서는 이동차량의 속도를 다양하게 변화시켜 차량 속도에 따른 포장 슬래브의 동적 거동을 비교 분 석하였으며 이동차량이 CRCP의 여러 위치에서 정지하도록 하여 정지 위치에 따른 거동도 분석하였다. 실험 결과, 차량 이 CRCP를 통행할 경우 차량 속도 및 정지 위치에 따른 포장 슬래브의 동적 변형률은 매우 유사한 것으로 분석되었다.

국내의 도심지 도로는 대부분 아스팔트 포장으로 시공되어 있으며 아스팔트 포장의 공용수명은 콘크리트 포장의 공용 수명에 비해 짧아 잦은 재시공 및 유지보수 작업이 필요하다. 도심지 특성상 포장 재시공 및 유지보수를 실시할 경우 작 업 시간 동안 교통차단을 유발하여 도로 이용자의 불편을 초래하게 된다. 따라서 서울특별시에서는 신설구간인 헌릉로의 중앙버스정류장 구간에 도심지 최초로 현장타설 방식의 연속철근 콘크리트 포장을 시공하였다. 본 연구에서는 중앙버스 정류장 구간에 시공한 연속철근 콘크리트 포장의 철근 거동에 대한 분석을 수행하여 철근의 응력이 가장 크게 발생하는 균열부에서의 철근 응력의 적정성을 분석하였다. 분석 결과, 균열부에서 멀어질수록 철근의 변형률이 뚜렷하게 감소하는 것을 확인하였으며 균열부에서 약 15cm 정도만 이격되어도 철근의 변형률이 급격하게 감소하여 철근과 콘크리트 간의 부착이 적절한 것으로 분석되었다. 또한, 균열부에서 발생한 철근의 변형률을 응력으로 환산하면 약 50MPa 정도로 철근 의 항복강도인 400MPa에 비해 매우 작아서 연속철근 콘크리트 포장의 우수한 공용성을 확보한 것으로 분석되었다.

한국형 포장설계법(KPRP)은 한국의 기후, 교통, 재료 조건을 반영하여 개발된 포장설계법으로, 성능 기반 분석과 역학적-경험적 원 리를 결합하여 국내 도로포장의 내구성과 효율성 향상에 기여해왔다. KPRP는 지역별 환경 데이터, 교통 하중, 재료 특성을 고려하 여 최적의 포장 구조를 설계하며, 2011년 개발 이후 도로포장의 수명 연장과 경제성 향상을 이루어냈다. 그러나 KPRP에 적용되는 기후 및 교통 데이터는 2000년대 초반의 자료를 기반으로 하고 있어, 현재 기준으로 약 10년 이상의 차이가 존재한다. 이에 따라 최 신 데이터를 반영하여 포장설계를 개선할 필요성이 제기되고 있다. 본 연구에서는 최근 10년간의 최신 기후 데이터를 활용하여 줄눈 콘크리트 포장(JCP)의 콘크리트 슬래브 컬링 시간을 계산하고, 이를 기반으로 온도응력 및 교통응력의 산정 방식을 현 시점에 맞게 개선하고자 한다. 또한, 2023년 도로포장관리시스템(PMS) 데이 터를 이용하여 한국도로공사가 관리하는 모든 고속국도 중 JCP가 적용된 구간을 대상으로 표면 균열(SD), 설계 차로별 AADT, 관 리구간별 도로 연장, 차로 폭 등의 데이터를 분석하였다. 이를 통해 각 도로의 피로균열율을 산정하고, 고속국도를 대상으로 줄눈 콘 크리트 포장의 전이함수를 개선하여 보다 정밀한 설계를 가능하게 하고자 한다. 본 연구는 최신 기후 및 교통 데이터를 반영한 KPRP 기반 줄눈 콘크리트 포장설계의 실현에 기여할 것으로 기대된다.