Japan Concrete InstituteActa Medica Okayama1346-80142252024Freeze-thaw Resistance of Concrete using Ground Granulated Blast-furnace Slag and Blast-furnace Slag Sand in Salt Water253266ENToshikiAyanoFaculty of Environmental, Life, Natural Science and Technology, Okayama UniversityTakashiFujiiFaculty of Environmental, Life, Natural Science and Technology, Okayama UniversityKanakoOkazakiDivision of Social Engineering and Environmental Management, Graduate School of Environmental and Life Science, Okayama UniversityThe freeze-thaw resistance of concrete is significantly lower in salt water than in fresh water. Concrete deteriorates through repeated freezing and thawing, but in salt water, freezing alone leads to destruction. This paper investigated the effect of calcium hydroxide in concrete on the failure of concrete under such low temperatures. Calcium hydroxide precipitates at the transition zone between aggregate and cement paste due to the hydration of cement. The lower the temperature and the higher the concentration of salt water, the more calcium hydroxide dissolves. From concrete, more calcium hydroxide is eluted in salt water than in fresh water. This accelerates the deterioration of mortar and concrete due to freeze-thaw action. Mortar and concrete using ground granulated blast-furnace slag produces less calcium hydroxide. In mortar and concrete using blast-furnace slag sand, calcium hydroxide precipitated around the aggregate reacts with cement paste and blast-furnace slag sand to modify the transition zone. From these results, it was clarified that concrete using blast-furnace slag exhibits high freeze-thaw resistance even in salt water.<br>
This paper is the English translation of the authors’ previous work [Ayano, T., Fujii, T. and Okazaki, K., (2023). “Freeze-thaw resistance of concrete using ground granulated blast-furnace and blast-furnace slag sand in salt water.” Japanese Journal of JSCE, 79(12), 23-00042. (in Japanese)].No potential conflict of interest relevant to this article was reported.Acta Medica Okayama2013Strength and Durability of Concrete with Blast Furnace SlagT4-6 2ENPaweenaJARIYATHITIPONGKazuyoshiHOSOTANITakashiFUJIIToshikiAYANOThe properties of concrete using blast furnace as binder and fine aggregate have been
investigated in this study. The experiments focus on the properties of concrete such as
compressive strength and young's modulus, carbonation, diffusion of chloride ions,
resistance to sulfate attack and resistance to freeze and thaw. The experimental results show
that when blast furnace slag is used in concrete, it improves the durability properties of
concrete. However, the combination of using both blast furnace slag as binder and fine
aggregate shows a greater improvement of those properties of concrete.No potential conflict of interest relevant to this article was reported.Acta Medica Okayama2013Effect of chemical admixture on property of fresh mortar using sludge waterW1-7 3ENTakashiFUJIITadashiSAITOToshikiAYANOAddition of sludge water as a part of mixing water had little influence on strength and
durability of hardened concrete, but caused a slump decrease of fresh concrete. The decrease
of slump was improved by addition of a certain set retarder such as gluconate into sludge
water due to control of cement hydration. Some of polymers were also effective in
improvement of slump. However hydration of cement was observed in those cases of
polymers. Therefore it is presumed such the polymers improve slump not by hydration
control effect but by another one.No potential conflict of interest relevant to this article was reported.Acta Medica Okayama2013THE SULFURIC ACID RESISTANCE OF CONCRETE WITH BLAST FURNACE SLAG581586ENPaweenaJARIYATHITIPONGKazuyoshiHOSOTANITakashiFUJIIToshikiAYANOThe deterioration of concrete by sulfuric acid attack in sewage environments has become a serious problem. In this
study, it was shown that the resistance to sulfuric acid of mortar and concrete can be improved by using a
blast-furnace slag fine aggregate to the total amount of fine aggregate. When mortar or concrete reacts to sulfuric
acid, dihydrated gypsum film is formed around the particulate of the fine aggregate. This dihydrated gypsum film
could retard the penetration of sulfuric acid, thus improving the resistance to sulfuric acid. However, the resistance
to sulfuric acid depends on the hardness of the dihydrated gypsum film.No potential conflict of interest relevant to this article was reported.日本材料学会Acta Medica Okayama132013コンクリートの耐久性に及ぼす高炉スラグ細骨材の影響16ENTakashiFUJIIPaweenaJARIYATHITIPONGKazuyoshiHOSOTANIToshikiAYANO本研究は，高炉スラグを用いたコンクリートの中性化，耐硫酸塩性および凍結融解
抵抗性の検討を行ったものである．高炉スラグを細骨材に用いることで，細骨材周辺に集
積する水酸化カルシウムがなくなり，骨材表面とペーストとの界面が強固なものとなるた
め，コンクリートの中性化および耐硫酸塩性が向上する．また，結合材の一部を高炉スラ
グ微粉末に置き換えるか，または，細骨材に高炉スラグ細骨材を用いたコンクリートでは，
AE 剤を用いることなく，また，蒸気養生を行っても，十分な凍結融解抵抗性が得られる．No potential conflict of interest relevant to this article was reported.Acta Medica Okayama2007鉄鋼スラグ水和固化体の性能改善と設計手法に関する研究ENTakashiFujiiNo potential conflict of interest relevant to this article was reported.