EMA-co-DAMA were synthesized from 2-diethylaminoethyl metacrylate and ethylhexyl metacrylate in acrylmonomer. To facilitate water emulsification, acrylic copolymer was cationized by acetic acid to produce acetated acrylic copolymer. The structures of the synthesized copolymer and acetated copolymers were confirmed by IR, NMR, and molecular weight was measure by GPC, and C.H.N elemental analysis. Acetated acrylic copolymers were perfectly emulsified in water and showed increased emulsion stability. Polymer dispersion for cement modifier[(PDCM-PED) water proof agent of cement for concrete in building construction] was prepared by blending of the guaternized acrylic copolymer syndisized above, sodium silicate, sodium gluconate and oleic acid emulsion. The result with prepared polymer dispersion of cement modifier was examined, and it was found that excellent waterprooffing effect ; Water permeability ratio is 0.50 under the water pressure of 100g/cm2 and 0.60 under 3kg/cm2, and water absorption ratio is 0.42~0.50 and 1.0~1.02 compressive strength ratio at mixed of water/PDCM-PED is 50 times.
The purpose of this study is to estimate the permeability coefficient of concrete using mass hydrophobation agent. Experiments were carried out by making concrete specimens with different amounts of mass hydrophobation agent. It is considered that the pores are filled in the internal structure of the concrete by the expansion of the mass hydrophobation agent.
The purpose of this study is to estimate the permeability coefficient of concrete using mass hydrophobation agent. Experiments were carried out by making concrete specimens with different amounts of mass hydrophobation agent. It is considered that the pores are filled in the internal structure of the concrete by the expansion of the mass hydrophobation agent.
콘크리트용 무기계 방수제는 내부 막을 형성하지 않기 때문에 무기계 방수제의 침투깊이 정량적으로 평가하기 어렵다. 그러나 무기계 방수제의 침투깊이 평가는 일관된 침투효율을 확보하는데 있어서 매우 중요한 평가지표 중 하나이다. 따라서 본 논문에서는 콘크리트용 무기계 방수제의 침투깊이 측정방법을 고안하였으며, 고안된 침투깊이 측정방법을 통하여 기존 무기계 방수제의 침투깊이를 평가하였다. 실험결과 고안된 무기계 방수제의 침투깊이 측정방법을 통하여 평가된 침투깊이는 90% 이상의 신뢰성이 있는 것으로 나타났다.
The study area is located on the western coast, and the inner development construction has been ongoing since 2011. The purposes of current study are to effectively simulate and quantitatively predict a temporal and spatial distributions of water temperature and salinity due to the stages of inner development construction in saemangeum reclaimed area. The transient-state numerical modeling using EFDC model is done, and the numerical simulation results are validated reasonably by repetitive numerical model calibration procedures with respect to field measurements of water temperature and salinity. The spatial distributions of water temperature and salinity show similar trends before and after construction of the dikes. In spring season, the salinity has maximum value of 21 psu, while, in summer season, the salinity shows 7 psu in a whole modeling domain. Thus, it is clearly observed that salt water is replaced by freshwater. However, the salinity and temperature reach their initial conditions at the end of the year. The salinity after construction of the dikes is lower than that before construction of them at Mankyeong area. On the other hands, after construction of the dikes, the salinity after dredging operations is higher than that before dredging. Because drastical increasing of water volume in Saemangeum Lake leads to increasing of stagnation time at bottom layer, and salt water is easily intruded to the two estuaries. Therefore, it may be concluded that hydrodynamic characteristics on Saemangeum are dominated by either Mankyeong and Dongjin discharge or sluice gates in/out-flow amounts, and thus they must be properly considered when rigorous and reasonable predictions of water temperature and salinity according to the stages of inner development construction.
In this study, the actual states and cases utilizing lake dykes were investigated focusing on large-scale reclamation project in domestic and instances in advanced foreign countries. The attitudes investigation concerning lake dykes utilization was performed to residents in-and-around Saemangeum. According to the research result, in domestic the utilization of lake dyke have not attracted attention because maximizing land use, which was the primary purpose of reclamation project at the early stage, has been emphasized so far. The advanced foreign countries, however, not only make use of farmland, but also develop activities employing lake dykes. According to the result of an analysis for local residents' attitudes, they want to be used Saemangeum lake dykes as a multifunctionality facilities performing a role of environment friendly equipment as well as a breakwater. They also require further investigation and to be introduced new system far utilizing as a multifunctionality facilities. Recently, green tourism is getting attention more and more owing to laying stress on balanced development of country and improvement on life quality of rural residents and launching five days in duty. It is believed that on this favorable trend lake dykes an be employed as a primary tourism resource if its utilization is developed actively.