|
Title |
Effects of Limestone Powder and Silica Fume on the Hydration and Pozzolanic Reaction of High-Strength High-Volume GGBFS Blended Cement Mortars
|
|
Authors |
정지용(Ji-Yong Jeong) ; 장승엽(Seung-Yup Jang) ; 최영철(Young-Cheol Choi) ; 정상화(Sang-Hwa Jung) ; 김성일(Sung-Il Kim) |
|
DOI |
http://dx.doi.org/10.4334/JKCI.2015.27.2.115 |
|
Keywords |
고로슬래그 미분말 ; 고강도 ; 치환율 ; 분말도 ; 수화 ; 포졸란 반응 ground granulated blast-furnace slag(GGBFS) ; high strength ; cement replacement ratio ; fineness ; hydration reaction ; pozzolanic reaction |
|
Abstract |
This study investigated the fluidity, heat of hydration, setting time, strength development, and characteristics of hydration and pozzolanic reactions of high-strength high-volume ground granulated blast-furnace slag(GGBFS) blended cement pasts with the water-to-binder ratio of 20% by experiments, and analyzed the effects of the replacement ratio and fineness of GGBFS on the hydration and pozzolanic reaction. The results show that, in the high-strength mixtures with low water-to-binder ratio, the initial hydration is accelerated due to the “dilution effect” which means that the free water to react with cement increases by the replacement of cement by GGBFS, and thus, strengths at from 3 to 28 days were higher than those of plain mixtures with ordinary Portland cement only. Whereas it was found that the long term strength development is limited because the hydration reaction rates rapidly decreases with ages and the degree of pozzolanic reaction is lowered due to insufficient supply of calcium hydroxide according to large replacement of cement by GGBFS. Also, the GGBFS with higher fineness absorbs more free water, and thus it decreases the fluidity, the degree of hydration, and strength. These results are different with those of normal strength concrete, and therefore, should be verified for concrete mixtures. Also, to develop the high-strength concrete with high-volume of GGBFS, the future research to enhance the long-term strength development is needed.
|