• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.345-346
• /
• 2010

The overall quality of underwater concrete will ultimately be affected by factors such as performance of antiwashout admixture and mix proportions of concrete. Of these, performance of antiwashout admixture may significantly influence quality of underwater concrete. Thus, objectives of this experimental research are to evaluate the performance such as slump flow, setting time, compressive strength, and water segregation of the concrete containing antiwashout admixture. It was observed from the test results that concrete containing antiwashout admixture was found to improve quality of concrete such as fluidity, compressive strength, and antiwashout compared to plain concrete.

• Journal of the Korea Concrete Institute
• /
• v.26 no.6
• /
• pp.679-686
• /
• 2014

In this research, the mix proportion of the antiwashout underwater concrete with the mineral admixture was evaluated. It can reduce the amount used of the antiwashout admixture (hereinafter referred to as "AWA") and satisfy the properties of concrete. In addition, the review for the difference of the test and practical affairs were conducted. Optimized unit quantity of water of antiwashout underwater concrete and the amount used of AWA was revealed by $190kg/m^3$, 0.9%/W, respectively. In particularly, the mix design is reduced by 5% than the W/B of target strength even though the W and AWA reduced. Therefore, it will have the economical feasibility and qualities including the material separation, resistance characteristic and compressive strength, and etc. The stable value was shown in 1 point of minute passed in the measurement of the turbidity amounts using the turbidimeter after the checker insertion. However, it needs to be reviewed for the interrelationship between turbidity measuring machine and KCI-AD102 standard method. There were no significant differences of compressive strength of specimens in the water depending on the production methods.

• Magazine of the Korea Concrete Institute
• /
• v.8 no.5
• /
• pp.179-187
• /
• 1996

Many underwater concrete structures have been constructed recently in proportion to the increase of ocean developments. The research for the underwater concrete construction was mainly focused in view of placing method. Recently, special admixture agents of concrete were developed for antiwashout concrete under water in some foreign nations. They had successful results in experiments and site constructions. However. there are seldom experimental results or placements in domestic contry. In this paper. We had carried out property tests of fresh and hardened concrete with refer to successful results in experiments and site construction and investigated the physical variation of the antiwashout underwater concrete considering the interaction between antiwashout admixture and other ones. We have decided the optimal mix proportion fb;r antiwashout underwater concrete under standerd sea state.

• 레미콘
• /
• no.10 s.69
• /
• pp.19-26
• /
• 2001

• Journal of the Korean Ceramic Society
• /
• v.39 no.10
• /
• pp.970-976
• /
• 2002

In this paper, the slump flow of the concrete, suspension, pH, corrosion effect, bleeding and the characteristics of coompressive strength were analyzed using antiwashout underwater admixture and antiwashout underwater agent+corrosion inhibitor mixed admixtures(1type). The results showed that there were no rare difference in physical properties but in the results of rapid corrosion tests there were lots of corrosion inhibitor ratio differences between concrete using only antiwashout underwater admixture and the corrosion inhibitor mixed(1type). In the case of only antiwashout underwater admixture 5.4%, the case corrosion inhibitor mixed(1type) 0.07%, the Antiseawater of the concrete which uses the Corrosion Inibitor Mixed(1type) appeared highly.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.9
• /
• pp.59-67
• /
• 2014

With increasing underwater structure construction, there is high interest in offshore foundation and underwater grout and various study has been done in this area. For grout materials constructed underwater, it may be washed away by water or easily disturbed and material separation phenomenon during curing period always happens. As a result, it is difficult to ensure construction quality and this has a significant influence on the design strength of structure. In this study, to understand application effects of anti-washout admixture for the preplaced construction method, where grout is injected in monopile after filled with aggregates, laboratory tests on bleeding and compressive strength of anti-washout admixture were performed under various test conditions varying size of aggregate, water and cement ratio and admixture, and test results were compared and evaluated.

• Magazine of the Korea Concrete Institute
• /
• v.13 no.2
• /
• pp.30-37
• /
• 2001

• Magazine of the Korea Concrete Institute
• /
• v.8 no.2
• /
• pp.41-56
• /
• 1996

• Journal of Ocean Engineering and Technology
• /
• v.12 no.1
• /
• pp.153-161
• /
• 1998

This paper is to investigate the Fluidity of Antiwashout Underwater Concrete containing Fly Ash. The results of study are concluded as follows: the increase in Slump Flow value did not happen in the plain concrete which was replaced cement by Fly Ash; however, the maximum value could reach in the replacement of 30% of Fly Ash by weight of cement in the Fly Ash replaced concrete. On the condition of Fly Ash-Antiwashout Underwater Concrete in expecting 50 cm of the Slump Flow, it was necessary that the usage amount of Superplasticizer be around 1% of unit Binder, and 1.5% in 60 cm of the Slump Flow, respoectively.

• Journal of Korean Ophthalmic Optics Society
• /
• v.5 no.2
• /
• pp.167-173
• /
• 2000

Four glasses of $B_2O_3-Bi_2O_3-PbO-SiO_2$ (BBPS) system were prepared by melting the appropriate amounts of reagent grade oxides of $B_2O_3$, $Bi_2O_3$, PbO, and $SiO_2$ in an open crucible. The differential thermal analysis showed crystallization temperature decreased with increasing $Bi_2O_3$ or PbO content in the sample. The structures of glasses system were studied using scanning electron microscopy and Fourier transform-Infra red (FT-IR) spectroscopy. The UV cut-off and refractive index were found to be sensitive to the $Pb^{+2}$ and $Bi^{+3}$ content in the glasses. The behavior of the IR spectra of the glasses in the BP series was consistent with a role of $Bi_2O_3$ as a network former. In the BP series of glasses, the result of IR spectrum indicated that PbO behaved as a network former.