PURPOSES: The objective of this study is to evaluate the shear and tensile strength properties of adhesive road studs in asphalt and concrete pavements. METHODS: The 300 mm×300 mm×50 mm rectangular specimens were fabricated using asphalt and concrete mixture for installation of road studs. Four 140-mm-radius circular areas were milled on each specimen with depth of 5 mm to install the adhesive road studs. About 100 g of thermal melting adhesive was applied on the milled area, and then the road stud was bonded onto the surface of the asphalt and concrete mixture. Direct shear testing was conducted at a speed of 5 mm/min on the interface between road stud and asphalt and concrete materials. Tensile strength testing was also conducted on the prepared specimens by applying load with increase of 50 kPa per second. These tests were performed not only in dry condition but also in wet condition to determine the effect of moisture on the shear and tensile strengths. RESULTS : According to the shear testing results, the average shear strength of asphalt samples in dry and wet conditions are 0.509 and 0.234 MPa, respectively. From this testing, the shear strength of wet sample was found to be decreased by 50% with respect to that of the dry sample. Similar trends can be observed on the concrete samples. The average tensile strength of asphalt samples was 0.187 MPa at 1.5 mm of displacement in dry condition. The concrete sample has a 0.222 MPa average tensile strength, which is slightly higher than that of the asphalt sample because of the rough surface characteristics of the concrete sample. CONCLUSIONS: It is determined from this study that the shear and tensile strengths of road stud bonded on the surface of asphalt mixture are slightly lower than those on concrete samples. Regardless of the pavement type, the wet conditioning of the sample can decrease the shear and tensile strength by 50% those of the dry sample. In the future, the quality improvement of adhesive and increase of specific surface area should be considered to improve the bonding property between road stud and pavement surface.

Recent decades, maintenance and reconstruction have been paid attention to old buildings. Especially, it has been recognized that seismic retrofit measures are necessary for non-reinforced masonry buildings which are used for prevailing building constructions. However, such applications can be limited due to its excessive costs, long-period, and inherent difficulty in securing construction spaces. For this reason, different reinforcement methods have been proposed by previous researchers in the economic manner. This study carried out an adhesive retrofit material upgrading low workability and excessive costs of existing reinforcement methods and, in turn, verified the level of seismic reinforcement throughout experimental studies. In order for the objectives, masonry walls with an aspect ratio of 1.0 were designed and manufactured. Also, effective parameters which are affected by openings, adhesive material types, the number of reinforcement layers, and lateral load levels were established. Experimental results showed that MW specimens without openings were collapsed for low-seismic resistances resulting from rocking failure modes, while strength and displacement capacities were improved for reinforced openings. Also, R-MWO-3F specimens with opening which was enhanced for three layers of stiffener showed displacement, ductility capacities, and energy dissipating capacities in the stable manner, even satisfying the collapse prevention level proposed in the current seismic codes.

본 연구에서는 프라이머 도포 여·부 및 압축강도수준 그리고 바닥 마감재 시공재령에 따른 주차장용 바닥 마감재 부착성능을 평가 하였다. 또한 현행 KS 기준에서는 바닥 마감재 부착성능을 모르타르 공시체를 활용하여 평가하도록 제안하고 있지만, 실제 현장에서 바닥 마 감재는 콘크리트 상부면에 시공되기 때문에 바탕면 변화에 따른 부착성능을 추가변수로 계획하여 평가를 진행하였다. 모르타르는 현행기준에 서 제안하고 있는 배합표에 준하여 제작하였으며, 콘크리트 설계기준강도는 18, 30, 50 MPa로 계획하였다. 프라이머는 모르타르 및 콘크리트 재령 28일 변수에 따라 바닥 마감재와 함께 도포되었으며, KS 기준에 준하여 바닥 마감재 재령 일에 따라 부착성능을 평가하였다. 변수에 따른 부착성능 평가결과 바닥 마감재 재령이 경과함에 따라 바닥 마감재 부착성능은 향상되는 것으로 나타났으며, 압축강도가 높아짐에 따라 바닥 마감재 부착성능 또한 향상되는 것으로 나타났다. 이는 파괴양상을 고려하였을 때 콘크리트 쪼갬 인장강도의 영향을 받은 것으로 판단된다. 프 라이머 도포에 따른 부착성능은 유사한 것으로 나타났으며, 프라이머의 사용은 부착강도에 문제없이 콘크리트 표면의 내구성을 향상시킬 수 있을 것으로 판단된다. 또한 콘크리트 및 모르타르 바탕면의 부착강도 특성을 비교한 결과 바닥재의 부착강도는 구성재료 보다 압축강도에 큰 영향을 받는 것으로 나타났다. 따라서 현행 KS 기준의 모르타르 바탕면 실험체의 부착강도를 근거로 실제현장의 부착강도를 예측할 수 있을 것으로 판단된다.

This paper describes adhesive performance of between concrete and surface-material with different compressive strength and HPP (High Performance Polymer). To measure adhesive strength between concrete and surface-material flexural specimen(100×100×400 mm) with HPP were made and tested. The test result indicated that HPP was effective on low compressive strength than high compressive strength.