본 연구에서는 연속철근 콘크리트 포장(CRCP) 본선차로에 줄눈 콘크리트 포장(JCP) 길어깨가 적용되었을 경우에 타이바와 슬래브에 작용하는 응력을 완화시키고자 창녕밀양 고속도로 건설사업단 1공구에 타이바 규격 및 배치에 따른 3가지 경우를 구성하여 시험시공 을 실시하였다. 각 경우마다 타이바에 철근 변형률계를 설치하고 길어깨 포장에 콘크리트 변형률계를 설치하여 거동 분석을 수행하였 다. 분석 결과, 모든 경우에서 타이바와 콘크리트 슬래브의 응력이 강도에 비해 작게 분석되어 공용성에는 문제가 없음을 확인하였다. 향후 주기적인 거동 분석을 통해 최적의 타이바 배치 및 규격을 설계하여 콘크리트 포장의 공용성을 향상시키고자 한다.
PURPOSES : In this study, the initial behaviors of shoulder concrete slabs and tiebars at the longitudinal construction joints between the shoulder JCP and mainline CRCP are investigated. METHODS : The strains of concrete and tiebars were measured at the longitudinal construction joint between the CRCP and JCP. Measurements were performed using data accumulated over a month after concrete placement. The contact conditions were investigated by comparing the strains at each location. RESULTS : The longitudinal construction joints between the shoulder JCP and mainline CRCP exhibited the composite behavior of bonding and friction, and a virtual neutral axis was formed inside the JCP. At the connection of the shoulder concrete, the strain and temperature of the concrete were inversely proportional. The tiebars connecting the CRCP and JCP exhibited different behaviors depending on the bonding conditions around the tiebars of the construction joints. In the presumed state in which the bonding condition was maintained, the concrete temperature and tiebar strain were directly proportional; however, the presumed state of the separation condition exhibited an inversely proportional relationship. In the 24-h behaviors of the tiebars, the effects of the horizontal and curling movements overlapped, and the strains of the measured tiebars increased at the minimum and maximum temperatures of the shoulder JCP. CONCLUSIONS : The strains in the tiebars and concrete slabs primarily depended on the boundary conditions (bonding and friction) of the longitudinal construction joint between the shoulder JCP and mainline CRCP.
PURPOSES: The objective of this study is to evaluate the application of soil stabilization method for soft shoulder construction in the iRoad Project of Sri Lanka.
METHODS: Firstly, the quantitative analysis of soil strength improvement due to soil stabilization was done for soil samples collected from iRoad construction sites. Two types of soils were selected from iRoad Project sites and prepared for soil stabilization testing by the Road Development Authority. Secondly, the appropriate stabilizer was selected at given soil type based on test results. Two different stabilizers, ST-1 and ST-2, produced in Korea were used for estimating soil strength improvements. Finally, the optimum stabilizer content was determined for improving shoulder performance. The uniaxial compressive strength (UCS) test was conducted to evaluate the strength of stabilized soil samples in accordance with ASTM D 1633. The use of bottom ash as a stabilizer produced from power plant in Sri Lanka was also reviewed in this task.
RESULTS: It is found from the UCS testing that a 3% use of soil stabilizer can improve the strength up to 2~5 times in stabilized soft shoulder soils with respect to unstabilized soils. It is also observed from UCS testing that the ST-1 shows high strength improvement in 3% of stabilizer content but the strength improvement rate with increase of stabilizer content is relatively low compared with ST-2. The ST-2 shows a low UCS value at 3% of content but the UCS values increase significantly with increase of stabilizer content. When using the ST-2 as stabilizing agent, the 5% is recommended as minimum content based on UCS testing results. Based on the testing results for bottom ash replacement, the stabilized sample with bottom ash shows the low strength value.
CONCLUSIONS: This paper is intended to check the feasibility for use the soil stabilization technique for shoulder construction in Sri Lanka. The use of soil stabilizer enables to improve the durability and strength in soft shoulder materials. When applying the bottom ash as a soil stabilizer, various testings should be conducted to satisfy the specification criteria.
21세기 국가 경제 및 산업 발전에 따른 대규모 건설공사로 인해 발생되는 임목폐기물의 양은 매년 증가하고 있는 추세이다. 건전하고 지속가능한 개발과 자원순환의 개념 강화에 따라 건설현장에서 발생되는 임목폐기물을 단순 위탁 처리 방안에서 순환처리시스템으로 전환하는 것이 필요하므로, 건설현장에서 발생하는 임목폐기물의 자원순환처리를 위하여 관련 지침을 제정하고, 임목폐기물의 재활용 기술개발을 통한 실용화 방안을 마련하여 건설공사에서 발생한 임목폐기물의 재활용을 극대화 하여야 할 것이다.
본 논문에서는 도로 건설현장에서 발생하는 임목폐기물을 도로 보호길 어깨 포설에 재활용 하는 친환경 방안을 제시하였다. 기존에는 임목폐기물을 폐기물로 분류하여 폐기물 전문업체를 통해 위탁 처리하였으나, 임목폐기물의 효율적인 자원 낭비를 방지하고자 도로 보호길 어깨에 임목폐기물을 파쇄하여 포설하고자 한다. 포설 방법은 보호길 어깨를 굴착하여 파쇄칩을 포설 및 다짐한 후 친환경성 접착제를 살포한다. 위 활용 방안의 가능성을 입증하기 위해 우수 침식 시험기를 자체 제작 후 실내시험을 실시하였다. 또한 접착제의 친환경성 시험을 실시하였다. 침식 시험기를 이용한 시험 결과 현장 적용이 가능한 것으로 판단되었고, 친환경적인 활용 방법이라 할 수 있다.