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Shrinkage Properties of Blast Furnance Slag Cement Mortar by using Frost-Resistant Accelerator

내한촉진제를 사용한 고로시멘트 모르타르의 수축성상

  • Choi, Hyeong-Gil (Graduate School of Architecture, Kyungpook National University) ;
  • Lee, Jun-Cheol (Daegyeong Regional Infrastructure Technology Development Center, Kyungpook National University)
  • Received : 2018.10.30
  • Accepted : 2018.12.17
  • Published : 2019.02.20

Abstract

In this study, the effects of blast furnance slag cement and frost-resistant accelerator on shrinkage properties and shrinkage properties of mortar were examined. As a result, the addition of the frost-resistant accelerator to both OPC and BB has a small effect on the flash properties of mortar and the compressive strength increases from the early ages. In addition, when a frost-resistant accelerator is used in excess of the standard usage amount, it is necessary to examine the relationship of the expansion behavior at the early age, especially, between the compressive strength development and the expansion property. And it was confirmed that the addition of the frost-resistant accelerator tended to increase the shrinkage of mortar using the OPC and BB. With the addition of the frost-resistant accelerator, the amount of pores with a diameter of under the 30nm, especially, the amount of pores with a diameter of 20 to 30nm and the amount of pores with an ink-bottle decrease, and the shrinkage increases. And it is considered that a change in the amount this range of pores has a large effect on the shrinkage property.

고로시멘트와 내한촉진제를 병용한 모르타르의 수축특성 및 수축성상에 미치는 영향에 대해 검토했다. 그 결과, OPC, BB 모두 내한촉진제를 첨가함에 따라 굳지 않은 성상에 미치는 영향은 작고, 초기재령부터 압축강도는 커진다. 또한, 내한 촉진제를 표준 사용량 이상으로 다량 사용할 경우에는 초기재령에 있어서의 팽창거동, 특히 강도발현과 팽창성의 관계에 대해 검토할 필요가 있다. 한편, 내한촉진제를 첨가함으로써 OPC, BB 모두 길이변화는 증가하는 경향을 확인할 수 있었다. 내한촉진제를 첨가함에 따라 직경 30nm 이하의 세공량, 특히 직경 20~30nm의 세공량 및 ink-bottle 세공량이 감소하여 수축량은 커지게 되며, 이 범위의 세공량의 변화가 수축성상에 미치는 영향이 크다고 판단된다.

Keywords

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Figure 1. Overview of expansion rate test[10]

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Figure 2. Fresh properties

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Figure 3. Compressive strength

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Figure 4. Expansion rate

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Figure 7. Total porosity ratio

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Figure 8. CH content

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Figure 9. Differential pore volume of OPC

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Figure 10. Differential pore volume of BB

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Figure 11. Cumulative pore volume

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Figure 12. Cumulative pore volume

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Figure 13. Relationship between pore volume and drying shrinkage (under the 30nm and 8nm diameter)

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Figure 14. Relationship between pore volume and dryingshrinkage (between 20-30nm diameter and ink bottle pore)

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Figure 5. Drying shrinkage

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Figure 6. Mass change ratio

Table 1. Experimental programs

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Table 2. Used materials

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Table 3. Relationship between pore size and drying shrinkage

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