By developing molds and facilities to horizontally mold the functional part of the dry-cast concrete block, We intend to develop molds and a series of facilities to horizontally mold the functional part of the dry-cast concrete block to increase production per cycle while maintaining existing production methods and major facilities. In order to do so, CAE analysis is first required to develop molds and facilities for horizontally molding the functional part of the drycast concrete block in the horizontal direction. The procedure will be carried out by reviewing the validity of boundary conditions and physical properties, 3D modeling, grid generation, construction of analysis models, model validity, analysis according to frequency changes, and analysis according to physical properties. First, through the comparison of two-point support, three-point support, and two-point and three-point support in the constraint conditions, We would like to compare it with the actual molded product in the horizontal direction. But first of all, it is considered two-point support in the constraint conditions in this paper.

PURPOSES: The noise problem in concrete pavements has an adverse effect to the road user or nearby residents and is generated by the contact between a tire and the pavement surface. Exposed aggregate concrete pavements have been adopted to solve the tire-pavement noise problem in the United States and Europe. However, the efficiency of the coagulation retarder and exposure equipment used for this kind of pavement has not yet been investigated. Therefore, this study aims to evaluate the ability of the coagulation retarder and exposure equipment in producing the optimum exposed aggregate texture to achieve low pavement noise. A method for the exposure time selection has also been introduced here. METHODS: Sodium gluconate retarders were selected for use in this study. The retarder-water ratios of 1:1, 1:2, and 1:3 were investigated. The retarder was sprayed on a fresh concrete surface with rates of 200 g/m2, 300 g/m2, and 400 g/m2. The aggregates were then exposed to the surface using a steel brush and a water jet. The efficiencies for the low-noise texture, workability, and environmental impact produced by the two exposure devices were estimated. The EAN and the MTD were investigated according to the exposure time. RESULTS : The aggregates were exposed after the retarder was sprayed on the fresh concrete surface; the exposure lasted for 18 h to 26 h each time. The retarder-water ratio of 1:2 and the spraying rate of 300 g/m2 produced an optimum surface texture for low noise. Additionally, the steel brush performed more effectively in exposing aggregate to the surface compared to the water jet. The selected exposure time window (ETW) was 28 h to 35 h. CONCLUSIONS : The optimum retarder was the sodium gluconate retarder with a retarder-water ratio of 1:2 and a spraying rate of 300 g/m2. The steel brush showed a good performance in exposing the aggregates and showing the efficiency of the coagulation retarder in the given environment so as to produce the quality control condition. The ETW was influenced by the construction, mixture design, and construction environment; however, the selected ETW in this study was 26 h~35 h.

PURPOSES: This study is to investigate the mechanical performance of the fiber reinforced lean concrete with respect to different types of fibers. METHODS: Increased vehicle weight and other causes from the exposed conditions have accelerated the deteriorations of road pavement. A new multi-functional composite pavement system is being developed recently in order to extend service life and upgrade the pavement. A variety of tests were conducted before and after hardening of the concrete. RESULTS: From the test results, it was found that the use of different types of fibers did not affect the compressive strength development. This might be due to the inherent property of the lean concrete. When steel fibers were used relatively greater flexural strength and flexural fracture toughness were developed. Also addition of fly ash by replacing a part of Portland cement the fracture toughness was slightly increased. CONCLUSIONS: It has been known that the addition of fibers and use of mineral admixture can be positively considered in the development of multi-functional composite pavement system as its required mechanical performance is obtained.

배수성 포장에 있어 기능적 평가인 투수성 실험과 더불어 소음저감 측정을 서울시에서 시공한 구간에서 실시하였다. 소음측정은 두 가지 방법을 이용하였는데 그 방법은 Pass-by 방법과 NCPX(Novel Close Proximity) 방법을 이용하였다. Passby 방법은 교통량에 따른 소음원이 전달되는 것을 측정하는 방법이고, NCPX는 타어어와 포장 표면간의 마찰음을 측정하는 방법이다. 현장투수시험을 위해서는 총 5개의 구간에서 실시하였으며 각 구간마다 주행부와 비주행부로 나뉘어 측정하였다. 3개 구간의 Pass-by 측정을 위해서는 교통소음원 발생점으로부터 인접한 곳에서 측정을 실시하였고 또한 공원내부 혹은 단지 내부에서도 소음을 측정하였다. 마지막으로 NCPX 측정은 4군데서 실시하였다. 결과적으로 배수성 포장의 기능인 투수성과 소음저감이 2, 3년 사이에서는 그 기능을 잘 유지함을 알 수 있었다.

Functional Concrete Added Titanium Dioxide(TIO2) for photocatalysis was about a result strength Reduction by recent studies. Therefore, The purpose of the study is to review the possibility of TIO2 for using concrete admixture. As a result, Nano TIO2 for concrete admixture helps increased strength of concrete and here are some of the details. The compressive strength and flexural strength of cement mortar added same amount of Nano SF and TIO2 for admixture were development of strength a certain level each other. when Nano admixture use 10%, SF and TIO2 showed development of strength 60% and 40% each other gradually. If I use over 10% Both SF and TIO2, they showed irregular strength variations.

This paper presents basic study and data about anti-stripping functional filler of asphalt concrete utilizing by-product from limestone mine and other relevant industries. Especially ash from fluidized bed heat exchanger is considered as main material for the development of premixed asphalt filler which has good anti-stripping function. Ash from fluidized bed heat exchanger is able to contain calcium hydroxide and anhydrite by hydrating F-CaO, and this could be eco-friendly and anti-stripping functional asphalt filler utilizing by-product from mine and other industry through proper production process and mix with other powders of mine waste rock. Additionally this may have considerable price competitiveness compared to using existing liquid and powder anti-stripping agent.

In order to get effective and useful results after experiments, it is essential to classify and analyze data resulted from experiments. After these processes, obtained data enables us to have meaningful indications. During experiments, the main concern was to find the reducing ratio of formaldehyde concentrations compared to reference level of added material which affect the indoor air quality. Finally, the main objective of this study is to validate on optimal added amount of eco-friendly material for functional concrete.

Recently, many researchers have been executed on functional concrete in various fields. Especially, some researchers on added material for functional concrete are executed to improve the indoor air quality in daily living space. The indoor air quality was estimated by reducing capacity for the concentrations of formaldehyde. The main objective of this study is to provide a model to predict optimal amount of added material for functional concrete.

In recent, many researches are in progress to improve the indoor air quality. So, we proposed the specified concrete mixed with functional materials. In order to evaluate the performance of functional concrete, the mechanical properties, durability and the change in formaldehyde concentration were compared. According to the results, the specified concrete compared to normal concrete, showed similar levels in terms of mechanical properties and durability, while its effect of reducing concentrations of formaldehyde was notably efficient.