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Journal of the Korea Concrete Institute

J Korea Inst. Struct. Maint. Insp.
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  • Korea Citation Index (KCI)

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์Šฌ๋ž˜๊ทธ ๋‹ค๋Ÿ‰์น˜ํ™˜ ์ฝ˜ํฌ๋ฆฌํŠธ, ๋ฏธ์„ธ๊ณต๊ทน, ๋™๊ฒฐ์œตํ•ด, ๊ณต๊ทน๋ฅ 
high volume slag concrete, micropores, freezing-thawing, porosity

1. ์„œ ๋ก 

ํ•ด์–‘ํ™˜๊ฒฝ์— ๋…ธ์ถœ๋œ ์ฝ˜ํฌ๋ฆฌํŠธ ๊ตฌ์กฐ๋ฌผ์€ ๊ธฐํ›„๋ณ€ํ™”๋กœ ์ธํ•œ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ์˜ํ•ด ๋‚ด๋ถ€๊ท ์—ด, ํ‘œ๋ฉด๋ฐ•๋ฆฌ, ์ฒ ๊ทผ๋…ธ์ถœ ๋“ฑ์˜ ์—ดํ™”์— ์ทจ์•ฝํ•˜๋‹ค. ํŠนํžˆ ์šฐ๋ฆฌ๋‚˜๋ผ์˜ ๊ฒฝ์šฐ ๊ฒจ์šธ์ฒ ์— ๋‚ฎ์€ ๊ธฐ์˜จ ์œผ๋กœ ์ธํ•ด ์ฝ˜ํฌ๋ฆฌํŠธ ๋‚ด ๋ฌผ์ด ๋™๊ฒฐํ•˜์—ฌ ์ฝ˜ํฌ๋ฆฌํŠธ ๊ตฌ์กฐ๋ฌผ์˜ ์—ด ํ™”๊ฐ€ ์‰ฝ๊ฒŒ ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ๋‹ค. ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์€ ์ผ๋ฐ˜์ ์œผ๋กœ ๊ณต๊ธฐ๋Ÿ‰๊ณผ ์••์ถ•๊ฐ•๋„์— ํฐ ์˜ํ–ฅ์„ ๋ฐ›์œผ๋ฉฐ ์ด์™€ ๊ด€๋ จํ•˜์—ฌ ๋งŽ์€ ์—ฐ๊ตฌ์ž๋“ค์€ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ๊ณผ ๊ณต๊ธฐ๋Ÿ‰ ๋˜๋Š” ์••์ถ•๊ฐ•๋„๊ฐ€ ์„œ๋กœ ๋ฐ€์ ‘ํ•œ ์—ฐ๊ด€์ด ์žˆ๋‹ค๊ณ  ๋ณด๊ณ ํ•˜๊ณ  ์žˆ๋‹ค(Oh et al., 1993; Huaishuai et al., 2009).

๊ทธ๋Ÿฌ๋‚˜ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์€ ๊ณต๊ธฐ๋Ÿ‰ ๋ฐ ์••์ถ•๊ฐ•๋„ ์™ธ์—๋„ ์ฝ˜ํฌ๋ฆฌํŠธ ๋‚ด๋ถ€์˜ ๊ณต๊ทน๊ตฌ์กฐ์™€ ๋ฐ€์ ‘ํ•œ ๊ด€๋ จ์ด ์žˆ๋‹ค(H. Cai et al., 1998). Figure 1์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ณต๊ทน์˜ ํฌ๊ธฐ ๋ฐ ๋™๊ฒฐ์œตํ•ด ๋ฉ”์ปค๋‹ˆ์ฆ˜์„ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. ์ผ๋ฐ˜์ ์œผ๋กœ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ณต๊ทน์€ ๊ฒ” ๊ณต๊ทน(Gel pore), ๋ชจ์„ธ๊ด€ ๊ณต๊ทน(Capillary pore), ๊ฐ‡ํžŒ๊ณต๊ธฐ (Entrapped air), ์—ฐํ–‰๊ณต๊ธฐ(Entrained air) ๋“ฑ์œผ๋กœ ๊ตฌ๋ถ„ํ•  ์ˆ˜ ์žˆ๋‹ค(Pigeon et al., 1992). ๊ฒ” ๊ณต๊ทน์€ ๋ฌผ์„ ํก์ฐฉํ•˜๋Š” ํž˜์ด ์ƒ ๋Œ€์ ์œผ๋กœ ๊ฐ•ํ•ด์„œ ํ•ญ์ƒ ๋ฌผ๋กœ ์ฑ„์›Œ์ ธ ์žˆ๊ณ  ์ผ๋ฐ˜์ ์ธ ๊ธฐ์ƒ์กฐ๊ฑด ์—์„œ ๋ฌผ์ด ๋™๊ฒฐํ•˜์ง€ ์•Š๋Š” ํŠน์ง•์ด ์žˆ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๋ชจ์„ธ๊ด€๊ณต๊ทน์€ ์ˆ˜ํ™”๋ฌผ์งˆ์ด ๋ฏธ์ณ ๋‹ค ์ฑ„์šฐ์ง€ ๋ชปํ•˜์—ฌ ๋‚จ์€ ๊ณต๊ทน์œผ๋กœ์„œ ๋™๊ฒฐ ๊ฐ€ ๋Šฅํ•œ ๋ฌผ์ด ํฌํ•จ๋˜์–ด ์žˆ์–ด ๋™๊ฒฐํŒฝ์ฐฝ์••์— ๋”ฐ๋ฅธ ์ฝ˜ํฌ๋ฆฌํŠธ ๋‚ด๋ถ€ ๊ท ์—ด ๋ฐ ํ‘œ๋ฉด ๋ฐ•๋ฆฌ๋ฅผ ์ผ์œผํ‚ค๊ฒŒ ๋œ๋‹ค(Mehta et al., 2005; Olivier et al., 2008). ์ด๋•Œ ์—ฐํ–‰๊ณต๊ธฐ๋Š” ๋ชจ์„ธ๊ด€ ๊ณต๊ทน ๋‚ด ๋ฌผ์˜ ๋™๊ฒฐํŒฝ์ฐฝ์••์„ ์™„ํ™”ํ•˜๋Š” ์—ญํ• ์„ ํ•œ๋‹ค. ์ฝ˜ํฌ๋ฆฌํŠธ๊ฐ€ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์„ ๋ฐ›์œผ๋ฉด ๋ชจ์„ธ๊ด€๊ณต๊ทน ๋‚ด ๋ฌผ์ด ๋™๊ฒฐํ•˜๋ฉด์„œ ์•ฝ 9%์˜ ์ฒด ์ ํŒฝ์ฐฝ์ด ๋ฐœ์ƒํ•œ๋‹ค(Valenza et al., 2006(a); Valenza et al., 2007(b)). ์ฒด์ ํŒฝ์ฐฝ์œผ๋กœ ์ธํ•ด ๋ฏธ๋™๊ฒฐ์ˆ˜๋Š” ์ธ์ ‘ํ•œ ๊ณต๊ทน์œผ๋กœ ์ด๋™ํ•˜๊ฒŒ ๋˜๋Š”๋ฐ ๋™๊ฒฐ์ด ์ง„ํ–‰๋ ์ˆ˜๋ก ์ˆ˜์••์ด ๋ฐœ์ƒํ•˜์—ฌ ์ธ์žฅ ๋ ฅ์ด ์•ฝํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ ๋‚ด๋ถ€์กฐ์ง๋ถ€ํ„ฐ ์—ดํ™”๊ฐ€ ์ง„ํ–‰๋œ๋‹ค(Chung et al., 2010).

Fig. 1.

Pore Size and Mechanism of Freezing-Thawing

JKSMI-19-67_F1.jpg

๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์€ ๋ชจ์„ธ๊ด€๊ณต๊ทน์˜ ๋ถ€ํ”ผ๊ฐ์†Œ์™€ ๋ชจ์„ธ๊ด€๊ณต ๊ทน์˜ ๋™๊ฒฐ์— ์˜ํ•ด ๋ฐœ์ƒํ•˜๋Š” ๋™๊ฒฐํŒฝ์ฐฝ์••์„ ์™„ํ™”์‹œํ‚ค๋Š” ์—ฐํ–‰ ๊ณต๊ธฐ์˜ ํ˜•์„ฑ์„ ํ†ตํ•ด ํ–ฅ์ƒ์‹œํ‚ฌ ์ˆ˜ ์žˆ๋‹ค(Huaishuai et al., 2009). ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ๋ฅผ ์น˜ํ™˜ํ•  ๊ฒฝ์šฐ ๊ณต๊ทน๋ถ„ํฌ๊ฐ€ ๋ณ€ํ•˜๊ฒŒ ๋˜๋ฉฐ ๊ณต๊ทน๊ตฌ ์กฐ๋Š” ์Šฌ๋ž˜๊ทธ๋ฅผ ์น˜ํ™˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์— ์ค‘ ์š”ํ•œ ์š”์†Œ๋ผ๊ณ  ์–ธ๊ธ‰ํ•˜๊ณ  ์žˆ๋‹ค(Shi et al., 2012; Ali et al., 2014; Khan et al., 2010; Yang et al., 2003). ๋˜ํ•œ, ์ฝ˜ํฌ๋ฆฌ ํŠธ ํ˜ผํ™”์žฌ๋ฃŒ๋กœ์จ ์Šฌ๋ž˜๊ทธ๋ฅผ ํ™œ์šฉํ•˜๋ฉด ๋งคํŠธ๋ฆญ์Šค ์ถฉ์ „ํšจ๊ณผ์— ๊ธฐ์ธํ•˜์—ฌ ์ฝ˜ํฌ๋ฆฌํŠธ ๋‚ด๋ถ€์˜ ๋ชจ์„ธ๊ด€๊ณต๊ทน์˜ ์šฉ์ ์„ ๊ฐ์†Œ์‹œ์ผœ ์ˆ˜ํ™”๋ฐ˜์‘์— ์˜ํ•œ ๋‹ค๋ฅธ ๋ฏธ์„ธ๊ณต๊ทน๊ตฌ์กฐ๋ฅผ ๊ฐ€์งˆ ์ˆ˜ ์žˆ๋‹ค๊ณ  ๋ณด๊ณ  ํ•˜๊ณ  ์žˆ๋‹ค(So et al., 2011). ๋”ฐ๋ผ์„œ ์—ฐํ–‰๊ณต๊ธฐ๋ฅผ ํ†ตํ•œ ๋™๊ฒฐ์œต ํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์˜ ํ–ฅ์ƒ ์™ธ์—๋„ ์ฝ˜ํฌ๋ฆฌํŠธ ์ œ์กฐ ์‹œ ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ ๋ถ„๋ง์„ ํ™œ์šฉํ•  ๊ฒฝ์šฐ ๊ณต๊ทน๊ตฌ์กฐ ๊ฐœ์„ ์„ ํ†ตํ•œ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ ๋Šฅ์˜ ํ–ฅ์ƒ์„ ๋„๋ชจํ•  ์ˆ˜ ์žˆ์„ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

์ด์— ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ๊ณต๊ธฐ๋Ÿ‰์„ ๋™์ผํ•˜๊ฒŒ ์„ค์ •ํ•˜์—ฌ ์Šฌ๋ž˜๊ทธ ๋ฅผ ๋‹ค๋Ÿ‰ ์น˜ํ™˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์— ๋ฏธ์น˜๋Š” ๋ฏธ ์„ธ๊ณต๊ทน์˜ ์˜ํ–ฅ์„ ๊ฒ€ํ† ํ•˜๊ณ ์ž ํ•˜์˜€๋‹ค.

2. ์‹คํ—˜๊ณ„ํš ๋ฐ ๋ฐฉ๋ฒ•

2.1 ์‚ฌ์šฉ์žฌ๋ฃŒ

Table 1, 2๋Š” ์‚ฌ์šฉ์žฌ๋ฃŒ์˜ ๋ฌผ๋ฆฌโ‹…ํ™”ํ•™์  ์„ฑ์งˆ์„ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ ์ด๋‹ค. ์‹œ๋ฉ˜ํŠธ๋Š” KS F 5201 ๏ฝขํฌํ‹€๋žœ๋“œ ์‹œ๋ฉ˜ํŠธ๏ฝฃ์˜ ๊ทœ์ •์„ ๋งŒ ์กฑ์‹œํ‚ค๋Š” 1์ข… ๋ณดํ†ตํฌํ‹€๋žœ๋“œ์‹œ๋ฉ˜ํŠธ(C)๋ฅผ ์‚ฌ์šฉํ•˜์˜€์œผ๋ฉฐ, ๋ฐ€๋„ ๋Š” 3.15 g/cm3, ๋ถ„๋ง๋„๋Š” 3,500 cm2/g์ด๋‹ค. ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„ ๋ง์€ KS F 2563 ๏ฝข์ฝ˜ํฌ๋ฆฌํŠธ์šฉ ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง๏ฝฃ 3์ข…์˜ ๊ทœ ์ •์„ ๋งŒ์กฑ์‹œํ‚ค๋Š” ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง(GGBS)์„ ์‚ฌ์šฉํ•˜์˜€์œผ ๋ฉฐ, ๋ฐ€๋„๋Š” 2.90 g/cm3, ๋ถ„๋ง๋„๋Š” 4,196 cm2/g์ด๋‹ค. ์šฉ์„ ์˜ˆ๋น„ ์ฒ˜๋ฆฌ์Šฌ๋ž˜๊ทธ(PS)๋Š” ์ฒ ๊ฐ•๊ณต์ • ์ค‘ ์œ ํ•ด์„ฑ๋ถ„์ธ ํ™ฉ(S) ๋“ฑ์„ ์‡ณ๋ฌผ ์—์„œ ์ œ๊ฑฐํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๋ณ„๋„์˜ ์˜ˆ๋น„์ฒ˜๋ฆฌ ๊ณต์ •์„ ํ†ตํ•ด ๋ฐœ์ƒํ•˜ ๋Š” ์‚ฐ์—…๋ถ€์‚ฐ๋ฌผ๋กœ์จ ๋ฐ€๋„๋Š” 2.83 g/cm3, ๋ถ„๋ง๋„๋Š” 4,196 cm2/g ์ด๋‹ค. ์ž”๊ณจ์žฌ์™€ ๊ตต์€ ๊ณจ์žฌ์˜ ๋ฐ€๋„๋Š” ๊ฐ๊ฐ 2.56, 2.67 g/cm3์ด ๊ณ , ์ตœ๋Œ€์น˜์ˆ˜๋Š” ๊ฐ๊ฐ 5, 25 mm์ด๋ฉฐ, ํก์ˆ˜์œจ์€ 1.01, 1.39 % ์ด๋‹ค.

Table 1.

Physical Properties of Used Materials

Materials Physicalproperties
C Ordinary portlandcement,Density : 3.15 g/cm3, Blaine : 3,500cm2/g
GGBS Ground granulated blast-furnaceslag,Density : 2.90 g/cm3, Blaine : 4,196cm2/g
PS Pig iron preliminary treatmentslag,Density : 2.83 g/cm3, Blaine : 4,000cm2/g
S Fine aggregate (Seasand),Density:2.56g/cm3,Maximum size:5mm,Water absorption ratio : 1.01%
G Coarse aggregate (Crushedaggregate),Density:2.67g/cm3,Maximum size:25mm,Water absorption ratio : 1.39%
SP Polycarboxylate Superplasticizer
Table 2.

Chemical Properties of Used Materials

Materials Chemical composition(%)
SiO2 Al2O3 Fe2O3 CaO MgO Na2O K2O SO3 LOI
C 20.70 6.20 3.10 62.20 2.80 0.10 0.84 2.10 1.96
GGBS 32.75 15.61 0.50 43.51 4.41 0.25 0.49 0.04 2.44
PS 15.35 1.21 2.40 69.71 1.52 0.10 - 4.20 5.51

2.2 ์‹คํ—˜๊ณ„ํš

Table 3์€ ์‹คํ—˜๊ณ„ํš ๋ฐ ์ฝ˜ํฌ๋ฆฌํŠธ ๋ฐฐํ•ฉ์„ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์Šฌ๋ž˜๊ทธ๋ฅผ ๋‹ค๋Ÿ‰ ์น˜ํ™˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์— ๋ฏธ์น˜๋Š” ๋ฏธ์„ธ๊ณต๊ทน์˜ ์˜ํ–ฅ์„ ๊ฒ€ํ† ํ•˜๊ธฐ ์œ„ํ•ด ๋ณดํ†ต ํฌํ‹€๋žœ๋“œ์‹œ๋ฉ˜ํŠธ ์ฝ˜ํฌ๋ฆฌํŠธ, ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง๊ณผ ์šฉ์„ ์˜ˆ๋น„์ฒ˜ ๋ฆฌ์Šฌ๋ž˜๊ทธ๋ฅผ ํฌํ•จํ•œ ์Šฌ๋ž˜๊ทธ๋ฅผ 40, 70 % ์น˜ํ™˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ๋ฅผ ์ œ์กฐํ•˜์˜€๋‹ค. ๋˜ํ•œ, ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์€ ์••์ถ•๊ฐ•๋„์™€ ๋ฐ€์ ‘ํ•œ ๊ด€๋ จ์ด ์žˆ๊ธฐ ๋•Œ๋ฌธ์— ์„ค๊ณ„๊ธฐ์ค€๊ฐ•๋„๋ฅผ 24MPa์˜ ์ผ๋ฐ˜๊ฐ•๋„๋กœ ๋™์ผํ•˜๊ฒŒ ์„ค์ •ํ•˜์˜€๋‹ค. ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง์„ ์น˜ํ™˜ํ•  ๊ฒฝ์šฐ ์•• ์ถ•๊ฐ•๋„๊ฐ€ ๋‚ฎ์•„์ง€๋ฏ€๋กœ ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง์˜ ์ˆ˜ํ™”๋ฐ˜์‘์„ ์ด‰์ง„ ์‹œํ‚ค๊ณ ์ž ์ž๊ทน์ œ์™€ ์œ ์‚ฌํ•œ ์„ฑ๋ถ„์œผ๋กœ ๊ตฌ์„ฑ๋œ ์šฉ์„ ์˜ˆ๋น„์ฒ˜๋ฆฌ์Šฌ ๋ž˜๊ทธ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ์ดˆ๊ธฐ๊ฐ•๋„๋ฅผ ๊ฐœ์„ ํ•˜์˜€๋‹ค. C100, GGBS40, GGBS70์˜ ์Šฌ๋Ÿผํ”„๋Š” ๊ฐ๊ฐ 190, 200, 210 mm๋กœ ๋ชฉํ‘œ์Šฌ๋Ÿผํ”„ ๋ฅผ ๋งŒ์กฑํ•˜์˜€๋‹ค. ๋˜ํ•œ C100, GGBS40์˜ ๊ณต๊ธฐ๋Ÿ‰์€ 4.0, 4.3 %, ๊ทธ๋ฆฌ๊ณ  GGBS70์˜ ๊ฒฝ์šฐ ๊ณต๊ธฐ๋Ÿ‰์ด ๋‚ฎ๊ฒŒ ์ธก์ •๋˜์–ด AE์ œ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ 3.7 %๋กœ ๋ชฉํ‘œ๊ณต๊ธฐ๋Ÿ‰์„ ๋งŒ์กฑํ•˜์˜€๋‹ค.

Table 3

Experimental Plan and Mix Proportion of Concrete

Specimens fck(MPa) Slump(mm) Air(%) W/B(%) S/a(%) Unit weight(kg/m3) SP(B.%) AEagent(SP.%) Evaluationcontents
W B(binder) S G
C GGBS PS
C100 24 180 ยฑ30 4.0 ยฑ1.0 60 48 202 337 - - 816 880 - -
  • Compressive strength (MPa)

  • Relative dynamic modulus of elasticity (%) ? Weight loss (%)

  • Porosity (%)

GGBS40 60 48 202 202 128 7 812 874 - -
GGBS70 53 48 179 101 225 11 838 902 0.1 0.6

Figure 2๋Š” ๋™๊ฒฐ์œตํ•ด๋ฅผ ๋ฐ›์ง€ ์•Š๊ณ  ์ˆ˜์ค‘์–‘์ƒ ํ•œ ์••์ถ•๊ฐ•๋„ ์ธก์ •๊ฒฐ๊ณผ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. C100, GGBS40, GGBS70์˜ ์žฌ ๋ น 14์ผ ์••์ถ•๊ฐ•๋„๋Š” ๊ฐ๊ฐ 22.1, 22.6, 19.9MPa๋กœ ์ธก์ •๋˜์—ˆ ์œผ๋ฉฐ, ๋‚ฎ์€ ๊ฐ•๋„ ๋ฒ”์œ„์—์„œ ๋™๊ฒฐ์œตํ•ด ๋ฐ˜๋ณต ์ž‘์šฉ์— ์˜ํ•œ๋‚ด๋ ฅ ์ €ํ•˜๋ฅผ ์œ ๋„ํ•˜์˜€๋‹ค.

Fig. 2.

Compressive Strength

JKSMI-19-67_F2.jpg

์ผ๋ฐ˜์ ์œผ๋กœ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์€ ๊ณต๊ธฐ๋Ÿ‰๊ณผ ์••์ถ•๊ฐ•๋„์— ๋”ฐ ๋ฅธ ์˜ํ–ฅ์ด ํฌ์ง€๋งŒ ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์œ ์‚ฌํ•œ ๊ณต๊ธฐ๋Ÿ‰ ๋ฐ ์••์ถ•๊ฐ•๋„ ๋กœ ์‹คํ—˜์„ ๊ณ„ํšํ•˜์—ฌ ์Šฌ๋ž˜๊ทธ๋ฅผ ๋‹ค๋Ÿ‰ ์น˜ํ™˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋ฏธ์„ธ ๊ณต๊ทน์ด ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๊ฒ€ํ† ํ•˜์˜€๋‹ค.

2.3 ์‹คํ—˜๋ฐฉ๋ฒ•

์••์ถ•๊ฐ•๋„ ์‹œํ—˜์€ โˆ…100ร—200 mm์˜ ์›์ฃผํ˜• ์‹œํ—˜์ฒด๋ฅผ ์ œ์ž‘ ํ•˜์—ฌ ์ˆ˜์ค‘์–‘์ƒ ํ•œ ์ดํ›„ ์žฌ๋ น 3, 7, 14, 28, 56์ผ์—์„œ KS F 2405์— ์ค€ํ•˜์—ฌ ์ธก์ •ํ•˜์˜€๋‹ค.

๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์‹œํ—˜์€ ASTM C 666/C 666M์— ์ค€ํ•˜์—ฌ ์‹ค ์‹œํ•˜์˜€์œผ๋ฉฐ ๋ชจ๋“  ์‹œํ—˜์ฒด์˜ ๊ณต๊ทน ๋‚ด์— ๋ฌผ์ด ํฌํ•จ๋  ์ˆ˜ ์žˆ๋„๋ก ์ˆ˜์ค‘์–‘์ƒ ํ•œ ์‹œํ—˜์ฒด๋ฅผ ๋งค 30 ์‚ฌ์ดํด๋งˆ๋‹ค 300์‚ฌ์ดํด๊นŒ์ง€ ์ƒ ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜์™€ ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ์„ ์ธก์ •ํ•˜์˜€๊ณ  ์‹œํ—˜์ฒด๊ฐ€ ํŒŒ๊ดด๋˜ ์—ˆ์„ ๋•Œ๋Š” ์ธก์ •ํ•˜์ง€ ์•Š์•˜๋‹ค. ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์€ ์‹(1)๋กœ ๊ณ„์‚ฐํ•˜์˜€๋‹ค. ๋˜ํ•œ, ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ ๋งค 100 ์‚ฌ์ดํด๋งˆ๋‹ค ์••์ถ•๊ฐ•๋„๋ฅผ ์ธก์ •ํ•˜์—ฌ ๋™๊ฒฐ์œตํ•ด ๋ฐ˜๋ณต ์ž‘์šฉ์ด ์••์ถ•๊ฐ•๋„์— ๋ฏธ ์น˜๋Š” ์˜ํ–ฅ์„ ๊ฒ€ํ† ํ•˜์˜€๋‹ค.

(1)
P c = n 1 2 / n 2 ร— 100

์—ฌ๊ธฐ์„œ, Pc๋Š” ๋™๊ฒฐ์œตํ•ด c์‚ฌ์ดํด ํ›„์˜ ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜(%), n์€ ์ดˆ๊ธฐ์˜ 1์ฐจ ๊ณต๋ช… ์ง„๋™์ˆ˜(Hz), n1 ์€ ๋™๊ฒฐ์œตํ•ด c์‚ฌ์ดํด ํ›„์˜ 1์ฐจ ๊ณต๋ช… ์ง„๋™์ˆ˜(Hz)์ด๋‹ค.

์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ณต๊ทน๊ตฌ์กฐ๋ถ„์„์€ ASTM D 4284 ์ˆ˜์€์••์ž…์‹œํ—˜ ๋ฐฉ๋ฒ•(Mercury Intrusion Porosimetry)์— ์˜ํ•ด ์‹ค์‹œํ•˜์˜€์œผ๋ฉฐ, ์ด๋Š” ์ –์ง€ ์•Š๋Š” ์œ ์ฒด(์ˆ˜์€)๊ฐ€ ์••๋ ฅ์— ์˜ํ•ด ๊ณต๊ทน์— ์นจํˆฌํ•˜์—ฌ ์ˆ˜์€์˜ ๋ถ€ํ”ผ๋ฅผ ์ธก์ •ํ•˜๋Š” ์‹œํ—˜๋ฐฉ๋ฒ•์ด๋‹ค(Winslow et al., 1970). ์ˆ˜์€์••์ž…๋ฒ•์€ ๋‹ค์Œ์˜ ์‹(2)๋กœ ํ‘œํ˜„๋˜๋Š” Washburn ์‹ ์— ์˜ํ•ด ๊ณต๊ทน์˜ ๋ชจ์–‘์„ ์‹ค๋ฆฐ๋”ํ˜• ๋ชจ์„ธ๊ด€์œผ๋กœ ์ •์˜ํ•˜์—ฌ ์ˆ˜์€ ์ด ์นจํˆฌํ•˜๋Š” ๊ณต๊ทน์˜ ํฌ๊ธฐ๋Š” ์ ์šฉ๋œ ์••๋ ฅ์— ๋ฐ˜๋น„๋ก€ํ•˜๋Š” ๊ฒƒ์„ ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค(Ritter et al., 1949).

(2)
d = - 4 ฮณ cos $ heta$ P

์—ฌ๊ธฐ์„œ, d๋Š” ๊ณต๊ทน์ง๊ฒฝ, ฮณ๋Š” ์ˆ˜์€์˜ ํ‘œ๋ฉด์žฅ๋ ฅ, ฮธ ์€ ๊ณ ์ฒด์™€ ์ˆ˜์€์˜ ์ ‘์ด‰๊ฐ, P ๋Š” ์ˆ˜์€์••์ž…์••๋ ฅ์ด๋‹ค.

3. ์‹คํ—˜๊ฒฐ๊ณผ ๋ฐ ๊ณ ์ฐฐ

3.1 ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜ ๋ฐ ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ ์ธก์ •๊ฒฐ๊ณผ

์Šฌ๋ž˜๊ทธ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ ๊ฒ€ํ† ๊ฒฐ๊ณผ Table 4 ์— ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์„ ๋ฐ›์€ ์‹œํ—˜์ฒด๋ฅผ ๋‚˜ํƒ€๋ƒˆ์œผ๋ฉฐ, Figure 3์— ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์„ ๋ฐ›์€ ์Šฌ๋ž˜๊ทธ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜ ์ธก์ •๊ฒฐ๊ณผ๋ฅผ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ๋™๊ฒฐ์ˆ˜ ๋‹ด์ˆ˜์กฐ๊ฑด์—์„œ GGBS70 ์‹œํ—˜์ฒด ๊ฐ€ ๊ฐ€์žฅ ๋†’์€ ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๋ฅผ ๋‚˜ํƒ€๋ƒˆ์œผ๋ฉฐ ๋‹ค๋ฅธ ์‹œํ—˜์ฒด๋“ค ์— ๋น„ํ•ด ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์ด ์šฐ์ˆ˜ํ•œ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. C100 ์‹œํ—˜์ฒด๋Š” 150์‚ฌ์ดํด์—์„œ ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ 60 %๋ฏธ๋งŒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ 180์‚ฌ์ดํด ์ดํ›„์—๋Š” ์‹œํ—˜์ฒด๊ฐ€ ํŒŒ๊ดด๋˜์–ด ์ƒ๋Œ€๋™ ํƒ„์„ฑ๊ณ„์ˆ˜๋ฅผ ์ธก์ •ํ•  ์ˆ˜ ์—†์—ˆ๋‹ค. GGBS40 ์‹œํ—˜์ฒด๋Š” C100 ์‹œ ํ—˜์ฒด๋ณด๋‹ค ๋‹ค์†Œ ๋†’์€ ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ ์ธก์ •๋˜์—ˆ์œผ๋ฉฐ 180์‚ฌ ์ดํด์—์„œ 60 %๋ฏธ๋งŒ์œผ๋กœ ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ ์ €ํ•˜๋˜์—ˆ์œผ๋ฉฐ 180 ์‚ฌ์ดํด ์ดํ›„์—๋Š” ์‹œํ—˜์ฒด์˜ ํŒŒ๊ดด๋กœ ์ธํ•˜์—ฌ ๋” ์ด์ƒ ์ธก์ • ํ•  ์ˆ˜ ์—†์—ˆ๋‹ค.

Fig. 3.

Relative Dynamic Modulus of Elasticity

JKSMI-19-67_F3.jpg
Table 4.

Specimens Exposed to Freezing-Thawing

Specimens Number of freezing-thawing cycles(Tap water) Specimens Number of freezing-thawing cycles(Sea water)
0 30 60 90 120 150 180 210 240 270 300 0 30 60 90 120 150 180 210 240 270 300
C100 JKSMI-19-67_T4-F1.jpg JKSMI-19-67_T4-F2.jpg JKSMI-19-67_T4-F3.jpg JKSMI-19-67_T4-F4.jpg JKSMI-19-67_T4-F5.jpg JKSMI-19-67_T4-F6.jpg JKSMI-19-67_T4-F7.jpg - - - - C100 JKSMI-19-67_T4-F8.jpg JKSMI-19-67_T4-F9.jpg JKSMI-19-67_T4-F10.jpg JKSMI-19-67_T4-F11.jpg JKSMI-19-67_T4-F12.jpg JKSMI-19-67_T4-F13.jpg JKSMI-19-67_T4-F14.jpg - - - -
GGBS40 JKSMI-19-67_T4-F15.jpg JKSMI-19-67_T4-F16.jpg JKSMI-19-67_T4-F17.jpg JKSMI-19-67_T4-F18.jpg JKSMI-19-67_T4-F19.jpg JKSMI-19-67_T4-F20.jpg - - - - JKSMI-19-67_T4-F21.jpg GGBS40 JKSMI-19-67_T4-F22.jpg JKSMI-19-67_T4-F23.jpg JKSMI-19-67_T4-F24.jpg JKSMI-19-67_T4-F25.jpg JKSMI-19-67_T4-F26.jpg JKSMI-19-67_T4-F27.jpg JKSMI-19-67_T4-F28.jpg - - - -
GGBS70 JKSMI-19-67_T4-F29.jpg JKSMI-19-67_T4-F30.jpg JKSMI-19-67_T4-F31.jpg JKSMI-19-67_T4-F32.jpg JKSMI-19-67_T4-F33.jpg JKSMI-19-67_T4-F34.jpg JKSMI-19-67_T4-F35.jpg JKSMI-19-67_T4-F36.jpg JKSMI-19-67_T4-F37.jpg JKSMI-19-67_T4-F38.jpg JKSMI-19-67_T4-F39.jpg GGBS70 JKSMI-19-67_T4-F40.jpg JKSMI-19-67_T4-F41.jpg JKSMI-19-67_T4-F42.jpg JKSMI-19-67_T4-F43.jpg JKSMI-19-67_T4-F44.jpg JKSMI-19-67_T4-F45.jpg JKSMI-19-67_T4-F46.jpg JKSMI-19-67_T4-F47.jpg JKSMI-19-67_T4-F48.jpg JKSMI-19-67_T4-F49.jpg JKSMI-19-67_T4-F50.jpg

๋™๊ฒฐ์ˆ˜ ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ๋Š” C100, GGBS40 ์‹œํ—˜์ฒด๊ฐ€ ๋‹ด์ˆ˜์กฐ ๊ฑด์— ๋น„ํ•ด ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ ๋” ๋‚ฎ๊ฒŒ ์ธก์ •๋˜์—ˆ์œผ๋ฉฐ ๋‘ ์‹œํ—˜ ์ฒด ๋ชจ๋‘ 180์‚ฌ์ดํด ์ดํ›„์—์„œ ์‹œํ—˜์ฒด์˜ ํŒŒ๊ดด๋กœ ์ธํ•˜์—ฌ ๋” ์ด ์ƒ ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๋ฅผ ์ธก์ •ํ•  ์ˆ˜ ์—†์—ˆ๋‹ค. ๋™๊ฒฐ์ˆ˜ ์กฐ๊ฑด์— ๊ด€๊ณ„ ์—†์ด GGBS70 ์‹œํ—˜์ฒด๋Š” ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ C100 ์‹œํ—˜์ฒด๋ณด ๋‹ค ๋†’๊ฒŒ ์ธก์ •๋˜์–ด ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์„ ํ™•๋ณดํ•  ์ˆ˜ ์žˆ์„ ๊ฒƒ์œผ ๋กœ ํŒ๋‹จ๋œ๋‹ค.

Figure 4๋Š” ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์„ ๋ฐ›์€ ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง์„ ์น˜ ํ™˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ ์ธก์ •๊ฒฐ๊ณผ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. ๋™ ๊ฒฐ์ˆ˜ ๋‹ด์ˆ˜์กฐ๊ฑด์—์„œ C100, GGBS40, GGBS70 ์‹œํ—˜์ฒด๋Š” 150 ์‚ฌ์ดํด๊นŒ์ง€ ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ์ด ๊ฐ๊ฐ 4.4, 3.4, 2.5 %๋กœ ๋น„์Šทํ•œ ์ˆ˜ ์ค€์„ ๋‚˜ํƒ€๋ƒˆ์œผ๋‚˜ 180์‚ฌ์ดํด์—์„œ ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ์ด ๊ฐ๊ฐ 12.8, 9.0, 2.5 %๋กœ ๋‚˜ํƒ€๋‚˜ GGBS70 ์‹œํ—˜์ฒด๋ฅผ ์ œ์™ธํ•œ ๋‚˜๋จธ์ง€ ์‹œํ—˜ ์ฒด๋Š” ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ์ด ๊ธ‰๊ฒฉํ•˜๊ฒŒ ๊ฐ์†Œํ•˜์˜€๋‹ค. C100, GGBS40 ์‹œํ—˜์ฒด๋Š” 180์‚ฌ์ดํด ์ดํ›„ ์‹œํ—˜์ฒด๊ฐ€ ํŒŒ๊ดด๋˜์–ด ์งˆ๋Ÿ‰์„ ์ธก์ •ํ•  ์ˆ˜ ์—†์—ˆ๋‹ค. ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ ๊ฐ€์žฅ ๋†’๊ฒŒ ์ธก์ •๋œ GGBS70 ์‹œ ํ—˜์ฒด๋Š” ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ๋”ฐ๋ฅธ ์—ดํ™”๊ฐ€ ๊ฐ€์žฅ ์ ์–ด ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ ์ด ํฌ์ง€ ์•Š์•˜๋‹ค.

Fig. 4.

Weight Loss

JKSMI-19-67_F4.jpg

๋™๊ฒฐ์ˆ˜ ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ๋Š” ๋ชจ๋“  ์‹œํ—˜์ฒด๊ฐ€ ๋‹ด์ˆ˜์กฐ๊ฑด์— ๋น„ํ•ด ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ์ด ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์ง€๋งŒ GGBS70 ์‹œํ—˜์ฒด์˜ ๊ฒฝ์šฐ ๋‹ค ๋ฅธ ์‹œํ—˜์ฒด์— ๋น„ํ•ด ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ์ด ๊ฐ€์žฅ ์ ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. GGBS70 ์‹œํ—˜์ฒด๋Š” ๋™๊ฒฐ์ˆ˜ ๋‹ด์ˆ˜์กฐ๊ฑด์—์„œ ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ๋„ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ๋”ฐ๋ฅธ ์ €ํ•ญ์„ฑ๋Šฅ์ด ์šฐ์ˆ˜ํ•œ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ํ•œํŽธ, ๋™๊ฒฐ์ˆ˜ ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ C100, GGBS40 ์‹œํ—˜์ฒด์˜ ํ‘œ๋ฉด ์—ดํ™”๊ฐ€ ๋‹ด์ˆ˜์กฐ๊ฑด์— ๋น„ํ•ด ์‹ฌํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚˜ ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ์ด ๊ธ‰๊ฒฉ ํ•˜๊ฒŒ ์ปค์ง€๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค.

Figure 5๋Š” ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์„ ๋ฐ›์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„ ๋น„ ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. ์••์ถ•๊ฐ•๋„ ๊ณ„์‚ฐ ์‹œ์—๋Š” ํ‘œ๋ฉด๋ฐ•๋ฆฌ์— ์˜ํ•œ ์‹œํ—˜์ฒด์˜ ๋‹จ๋ฉด์  ๊ฐ์†Œ๋ฅผ ๊ณ ๋ คํ•˜์—ฌ ์‚ฐ์ •ํ•˜์˜€๋‹ค. ๋™๊ฒฐ์œตํ•ด ์ž‘ ์šฉ์œผ๋กœ ์ธํ•œ ํ‘œ๋ฉด๋ฐ•๋ฆฌ์™€ ๋‚ด๋ถ€ ๋งคํŠธ๋ฆญ์Šค์˜ ๋ณ€ํ™”๊ฐ€ ๋‚˜ํƒ€๋‚˜ ๋™ ๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ๋”ฐ๋ฅธ ์••์ถ•๊ฐ•๋„์˜ ๊ฐ์†Œ๋ฅผ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค. ๋™ ๊ฒฐ์ˆ˜ ๋‹ด์ˆ˜, ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ C100, GGBS40 ์‹œํ—˜์ฒด๋Š” GGBS70 ์‹œํ—˜์ฒด์— ๋น„ํ•ด ์••์ถ•๊ฐ•๋„๊ฐ€ ํฌ๊ฒŒ ๊ฐ์†Œํ•˜๊ณ  ์žˆ์œผ๋ฉฐ ์ „์ฒด์ ์œผ ๋กœ GGBS70 ์‹œํ—˜์ฒด๊ฐ€ ๊ฐ€์žฅ ์ž‘์€ ์••์ถ•๊ฐ•๋„ ๊ฐ์†Œ๋ฅผ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ๋™๊ฒฐ์ˆ˜ ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ๋Š” ๋‹ด์ˆ˜์กฐ๊ฑด์— ๋น„ํ•ด ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ๋”ฐ๋ฅธ ํ‘œ๋ฉด๋ฐ•๋ฆฌ๊ฐ€ ์ฆ๊ฐ€ํ•˜์—ฌ ์••์ถ•๊ฐ•๋„๊ฐ€ ๋”์šฑ ๊ฐ์†Œํ•˜์˜€๋‹ค. ๊ทธ ๋Ÿฌ๋‚˜ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์ด ์šฐ์ˆ˜ํ•œ GGBS70 ์‹œํ—˜์ฒด๋Š” ๋™๊ฒฐ ์ˆ˜ ๋‹ด์ˆ˜, ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์ด ์ง„ํ–‰๋˜์–ด๋„ 300์‚ฌ์ด ํด๊นŒ์ง€ ํ‘œ๋ฉด๋ฐ•๋ฆฌ๊ฐ€ ์ ์–ด ์••์ถ•๊ฐ•๋„ ๋ณ€ํ™”๊ฐ€ ๋‹ค๋ฅธ ์‹œํ—˜์ฒด์— ๋น„ ํ•ด ํฌ์ง€ ์•Š์€ ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค.

Fig. 5.

Ratio of Compressive Strength of Concrete Exposed to Freezing-Thawing

JKSMI-19-67_F5.jpg

ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ ์ƒ๋Œ€๋™ํƒ„์„ฑ๊ณ„์ˆ˜, ์งˆ๋Ÿ‰๊ฐ์†Œ์œจ ๊ทธ๋ฆฌ๊ณ  ์••์ถ•๊ฐ• ๋„๊ฐ€ ๋‹ด์ˆ˜์กฐ๊ฑด์— ๋น„ํ•ด ๋” ๊ฐ์†Œํ•˜๋Š” ๊ฒƒ์€ ํ•ด์ˆ˜์˜ ์šฉ์กด์ด์˜จ์— ์˜ํ•ด ์ƒ์ƒ๋œ ๋ฐ˜์‘์ƒ์„ฑ๋ฌผ๋กœ ์ธํ•˜์—ฌ ์ฝ˜ํฌ๋ฆฌํŠธ ๋‚ด๋ถ€์กฐ์ง์ด ์นจ ์‹์„ ๋ฐ›์•„ ๋™๊ฒฐ์œตํ•ด ๋ฐ˜๋ณต์ž‘์šฉ์— ๋”ฐ๋ฅธ ์—ดํ™”๊ฐ€ ๋”์šฑ ๊ฐ€์†ํ™”๋œ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค(Lee et al., 2010).

3.2 ๊ณต๊ทน๋ฅ  ์ธก์ •๊ฒฐ๊ณผ

Figure 6์€ ๋™๊ฒฐ์œตํ•ด๋ฅผ ๋ฐ›์ง€ ์•Š์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ณต๊ทน๋ฅ  ์ธก์ • ๊ฒฐ๊ณผ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์œผ๋กœ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์„ ๋ฐ›์ง€ ์•Š๊ณ  ์ˆ˜์ค‘์–‘์ƒ ํ•œ ์‹œํ—˜์ฒด์˜ ๊ณต๊ทน๋ถ„ํฌ๋Š” ์ƒ์ดํ•œ ๊ฒฐ๊ณผ๋ฅผ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ๋ˆ„์ ๊ณต๊ทน ๋Ÿ‰์€ ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง์˜ ์น˜ํ™˜์œจ์ด ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ ๊ฐ์†Œํ•˜ ์˜€์œผ๋ฉฐ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์ด ๊ฐ€์žฅ ์šฐ์ˆ˜ํ•œ GGBS70 ์‹œํ—˜์ฒด ๋Š” ๋‹ค๋ฅธ ์‹œํ—˜์ฒด์— ๋น„ํ•ด ๊ณต๊ทน๋Ÿ‰์ด ์ ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด๋Š” ๊ณ ๋กœ ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง์ด ๊ฒฝํ™”์ฒด ๋‚ด๋ถ€์˜ ๊ณต๊ทน์„ ์ฑ„์›Œ์ฃผ๋Š” ํšจ๊ณผ๋กœ ์ธ ํ•˜์—ฌ ๊ณต๊ทน๋Ÿ‰์ด ์ค„์–ด๋“  ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

Fig. 6.

Cumulative Pore Volume of Specimen

JKSMI-19-67_F6.jpg

GGBS70, GGBS40, C100 ์‹œํ—˜์ฒด ์ˆœ์œผ๋กœ ๋ชจ์„ธ๊ด€๊ณต๊ทน์˜ ์–‘์ด ๋งŽ๊ธฐ ๋•Œ๋ฌธ์— ๋ชจ์„ธ๊ด€๊ณต๊ทน ๋‚ด ๋™๊ฒฐํ•  ์ˆ˜ ์žˆ๋Š” ๋ฌผ์˜ ์–‘์€ GGBS70 ์‹œํ—˜์ฒด๊ฐ€ ๊ฐ€์žฅ ์ ๊ฒŒ ๋˜์–ด ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์ด ๊ฐ€ ์žฅ ์šฐ์ˆ˜ํ•œ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

Figure 7์€ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์„ ๋ฐ›์ง€ ์•Š์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ฃผ์‚ฌ์ „ ์žํ˜„๋ฏธ๊ฒฝ ๊ด€์ฐฐ ๊ฒฐ๊ณผ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. GGBS40 ์‹œํ—˜์ฒด์—์„œ ๋Š” ์—ํŠธ๋ฆฐ์ž์ดํŠธ๊ฐ€ ๋ถ€๋ถ„์ ์œผ๋กœ ํ˜•์„ฑ๋œ ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ์—ˆ ์œผ๋ฉฐ GGBS70 ์‹œํ—˜์ฒด์—์„œ๋Š” ์ด๋ฅผ ํ™•์ธํ•  ์ˆ˜ ์—†์—ˆ๋‹ค. ์ด๋Ÿฌํ•œ ์—ํŠธ๋ฆฐ์ž์ดํŠธ์˜ ํ˜•์„ฑ์œผ๋กœ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ์˜ํ•œ ๋™๊ฒฐํŒฝ์ฐฝ์„ ์™„ํ™”ํ•˜๋Š” ๊ณต๊ฐ„์ด ์ œํ•œ๋˜์–ด ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์ด ์ทจ์•ฝํ•˜๊ฒŒ ๋œ๋‹ค(Stark et al., 1999).

Fig. 7.

SEM Images of Concrete at Age 14 Days (Water Curing)

JKSMI-19-67_F7.jpg

Figure 8์€ ๋™๊ฒฐ์ˆ˜ ๋‹ด์ˆ˜์กฐ๊ฑด์—์„œ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ๋”ฐ๋ฅธ ๋ชจ ์„ธ๊ด€๊ณต๊ทน์˜ ๊ณต๊ทน๋ถ„ํฌ ๋ณ€ํ™”๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. ๋ชฉํ‘œ๊ณต๊ธฐ๋Ÿ‰์„ (4.0ยฑ1.0) % ๋ฒ”์œ„๋กœ ์„ค์ •ํ•˜์˜€์Œ์—๋„ ๋ถˆ๊ตฌํ•˜๊ณ  ๋™๊ฒฐ์œตํ•ด ๋ฐ˜๋ณต ์ž‘์šฉ์— ๋”ฐ๋ผ ๋ชจ์„ธ๊ด€๊ณต๊ทน์˜ ๋ณ€ํ™”๊ฐ€ ๋‹ค๋ฅธ ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค.

Fig. 8.

Variation of Porosity for Concrete Exposed to Freezing- Thawing (Tap Water)

JKSMI-19-67_F8.jpg

C100, GGBS40 ์‹œํ—˜์ฒด๋Š” 0~200์‚ฌ์ดํด๊นŒ์ง€ ๋™๊ฒฐ์œตํ•ด ์ž‘ ์šฉ์„ ๋ฐ›์•˜์„ ๊ฒฝ์šฐ, 10~100 nm ํฌ๊ธฐ์˜ ๋ชจ์„ธ๊ด€๊ณต๊ทน์ด ๋‹ค๋ฅธ ํฌ ๊ธฐ์˜ ์˜์—ญ๋ณด๋‹ค ๊ฐ€์žฅ ํฌ๊ฒŒ ๊ฐ์†Œํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. C100, GGBS40 ์‹œํ—˜์ฒด๋Š” GGBS70์— ๋น„ํ•ด 0์‚ฌ์ดํด์—์„œ ๋ชจ์„ธ๊ด€๊ณต ๊ทน๋Ÿ‰์ด ๋งŽ์•„ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ๋”ฐ๋ผ ๋ชจ์„ธ๊ด€๊ณต๊ทน ๋‚ด ๋™๊ฒฐํ•  ์ˆ˜ ์žˆ๋Š” ๋ฌผ์ด ๋งŽ๊ฒŒ ๋œ๋‹ค. ๋น„๊ต์  ๋งŽ์€ ๋ชจ์„ธ๊ด€ ๊ณต๊ทน ๋‚ด ๋ฌผ์€ ๋™ ๊ฒฐํ•˜๋Š” ๊ณผ์ •์—์„œ ๋†’์€ ๋™๊ฒฐํŒฝ์ฐฝ์••์œผ๋กœ ์ธํ•ด ๋ชจ์„ธ๊ด€๊ณต๊ทน์˜ ํŒŒ๊ดด๋กœ ์ด์–ด์ ธ 10~100 nm ํฌ๊ธฐ์˜ ๋ชจ์„ธ๊ด€๊ณต๊ทน์ด ์ ์ฐจ์ ์œผ๋กœ ๊ฐ์†Œํ•œ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

GGBS70 ์‹œํ—˜์ฒด๋Š” 0~200์‚ฌ์ดํด๊นŒ์ง€ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์„ ๋ฐ› ์„ ๊ฒฝ์šฐ, C100, GGBS40 ์‹œํ—˜์ฒด์™€๋Š” ๋‹ค๋ฅด๊ฒŒ 10~100 nm ํฌ ๊ธฐ์˜ ๊ณต๊ทน์ด ์ฆ๊ฐ€ํ–ˆ๋‹ค๊ฐ€ 100~200์‚ฌ์ดํด๊นŒ์ง€๋Š” ๋‹ค์‹œ ๊ฐ์†Œํ•˜ ๋Š” ๊ฒฝํ–ฅ์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. GGBS70 ์‹œํ—˜์ฒด๋Š” 0์‚ฌ์ดํด์—์„œ ๋‹ค๋ฅธ ์‹œํ—˜์ฒด์— ๋น„ํ•ด ๋ชจ์„ธ๊ด€๊ณต๊ทน์ด ์ ๊ณ  ๋™๊ฒฐํ•  ์ˆ˜ ์žˆ๋Š” ๋ชจ์„ธ๊ด€๊ณต ๊ทน ๋‚ด ๋ฌผ์ด ์ ์–ด ๋™๊ฒฐํŒฝ์ฐฝ์••์ด ๊ฐ€์žฅ ๋‚ฎ์€ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค. ๋”ฐ๋ผ์„œ ๋‹ค๋ฅธ ์‹œํ—˜์ฒด์— ๋น„ํ•ด ๋‚ฎ์€ ๋™๊ฒฐํŒฝ์ฐฝ์••์œผ๋กœ ์ธํ•ด ๋ชจ์„ธ ๊ด€๊ณต๊ทน์˜ ํŒฝ์ฐฝ์ด ์„œ์„œํžˆ ์ง„ํ–‰๋˜์–ด ์ฆ๊ฐ€ํ•˜์˜€๋‹ค. ๋˜ํ•œ ๋™๊ฒฐ์œต ํ•ด๊ฐ€ ์ง„ํ–‰๋ ์ˆ˜๋ก ๋™๊ฒฐํŒฝ์ฐฝ์••์€ ๋”์šฑ ์ฆ๊ฐ€ํ•˜์—ฌ 200์‚ฌ์ดํด์— ์„œ ์ธ์žฅ๋ ฅ์ด ์•ฝํ•œ ๋ชจ์„ธ๊ด€๊ณต๊ทน๋ถ€ํ„ฐ ๊ธ‰๊ฒฉํžˆ ํŒŒ๊ดด๋œ ๊ฒƒ์œผ๋กœ ํŒ ๋‹จ๋œ๋‹ค.

๋™๊ฒฐ์ˆ˜ ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ๋Š” ๋‹ด์ˆ˜์กฐ๊ฑด๊ณผ ์œ ์‚ฌํ•œ ๊ณต๊ทนํฌ๊ธฐ๋ณ„ ๊ณต ๊ทน๋ถ„ํฌ๋ฅผ ๋‚˜ํƒ€๋ƒˆ์œผ๋ฉฐ, ๋™๊ฒฐ์ˆ˜ ์กฐ๊ฑด์ด ์Šฌ๋ž˜๊ทธ ๊ฒฝํ™”์ฒด ๋‚ด๋ถ€์˜ ๊ณต๊ทน๊ตฌ์กฐ์˜ ๋ณ€ํ™”์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์ด ํฌ์ง€ ์•Š์Œ์„ ํ™•์ธํ•˜์˜€์œผ ๋ฉฐ, ํ•ด์ˆ˜์— ์˜ํ•œ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์€ ํ‘œ๋ฉด๋ฐ•๋ฆฌ์— ๋” ํฌ๊ฒŒ ์˜ํ–ฅ ์„ ๋ฏธ์น˜๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค.

Figure 9๋Š” ๋™๊ฒฐ์ˆ˜ ๋‹ด์ˆ˜์กฐ๊ฑด์—์„œ ๋™๊ฒฐ์œตํ•ด ์ž‘์šฉ์— ๋”ฐ๋ฅธ 10~100 nm ํฌ๊ธฐ์˜ ๋ชจ์„ธ๊ด€๊ณต๊ทน์˜ ๋ณ€ํ™”๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. 0์‚ฌ ์ดํด์—์„œ 10~100 nm ํฌ๊ธฐ์˜ ๋ชจ์„ธ๊ด€๊ณต๊ทน์€ C100, GGBS40, GGBS70 ์ˆœ์œผ๋กœ ๋งŽ์•˜๋‹ค. C100, GGBS40 ์‹œํ—˜์ฒด๋Š” ๋™๊ฒฐ์œต ํ•ด ๋ฐ˜๋ณต์ž‘์šฉ์— ๋”ฐ๋ผ 10~100 nm ํฌ๊ธฐ์˜์—ญ์˜ ๋ชจ์„ธ๊ด€๊ณต๊ทน์ด ์ ์ฐจ ๊ฐ์†Œํ•˜๋Š” ๊ฒƒ์„ ํ™•์ธ ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋ฐ˜๋ฉด์— GGBS70 ์‹œํ—˜ ์ฒด๋Š” 100์‚ฌ์ดํด๊นŒ์ง€ ๋ชจ์„ธ๊ด€๊ณต๊ทน์ด ์ฆ๊ฐ€ํ•˜์˜€๋‹ค๊ฐ€ ๋‹ค์‹œ ๊ฐ์†Œ ํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ์ด๋Š” GGBS70 ์‹œํ—˜์ฒด๊ฐ€ ๋‹ค๋ฅธ ์‹œํ—˜์ฒด ์— ๋น„ํ•ด 0์‚ฌ์ดํด์—์„œ ๋ชจ์„ธ๊ด€๊ณต๊ทน์ด ์ ์€ ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค.

Fig. 9.

Variation of Capillary Pore of 10~100nm Size for Concrete Exposed to Freezing-Thawing

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4. ๊ฒฐ ๋ก 

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š”, ์Šฌ๋ž˜๊ทธ๋ฅผ ๋‹ค๋Ÿ‰ ์น˜ํ™˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋™๊ฒฐ์œต ํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์— ๋ฏธ์น˜๋Š” ๋ฏธ์„ธ๊ณต๊ทน์˜ ์˜ํ–ฅ์— ๋Œ€ํ•ด ๊ฒ€ํ† ํ•˜์˜€์œผ ๋ฉฐ, ๊ทธ ๊ฒฐ๊ณผ ๋‹ค์Œ๊ณผ ๊ฐ™์€ ๊ฒฐ๋ก ์„ ์–ป์—ˆ๋‹ค.

  1. ๋ฏธ์„ธ๊ณต๊ทน์ธ 10~100 nmํฌ๊ธฐ์˜ ๋ชจ์„ธ๊ด€๊ณต๊ทน์ด ์ ๊ฒŒ ๋‚˜ ํƒ€๋‚œ GGBS70 ์‹œํ—˜์ฒด๋Š” ๋™๊ฒฐ์ˆ˜ ๋‹ด์ˆ˜, ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ ์šฐ์ˆ˜ํ•œ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ๋ชจ์„ธ๊ด€๊ณต๊ทน์˜ ์–‘์ด ์ ์–ด ๋™๊ฒฐํ•  ์ˆ˜ ์žˆ๋Š” ๋ฌผ์˜ ์–‘์ด ์ ๊ณ  ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์— ์˜ํ–ฅ์„ ๋ฏธ์น˜๋Š” ์—ํŠธ๋ฆฐ์ž์ดํŠธ๊ฐ€ ๋ณด์ด์ง€ ์•Š ์•˜๊ธฐ ๋•Œ๋ฌธ์— ์šฐ์ˆ˜ํ•œ ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์„ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์œผ ๋กœ ํŒ๋‹จ๋œ๋‹ค.

  2. ๋™๊ฒฐ์ˆ˜ ๋‹ด์ˆ˜, ํ•ด์ˆ˜์กฐ๊ฑด์—์„œ GGBS70 ์‹œํ—˜์ฒด๋Š” ๋™๊ฒฐ์œต ํ•ด ์ž‘์šฉ์— ๋”ฐ๋ฅธ ์••์ถ•๊ฐ•๋„์˜ ๋ณ€ํ™”๊ฐ€ ๋‹ค๋ฅธ ์‹œํ—˜์ฒด์— ๋น„ ํ•ด ์ž‘์•˜๋‹ค. ์ด๋Š” GGBS70 ์‹œํ—˜์ฒด๊ฐ€ ๋‹ค๋ฅธ ์‹œํ—˜์ฒด์— ๋น„ ํ•ด 300์‚ฌ์ดํด๊นŒ์ง€ ํ‘œ๋ฉด๋ฐ•๋ฆฌ๊ฐ€ ์ ์–ด ์••์ถ•๊ฐ•๋„์˜ ๋ณ€ํ™” ๊ฐ€ ์ž‘์€ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

  3. ๋™๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์€ ์—ฐํ–‰๊ณต๊ธฐ์˜ ํ˜•์„ฑ ์™ธ์—๋„ ๋ฏธ์„ธ๊ณต ๊ทน๊ตฌ์กฐ ๊ฐœ์„ ์„ ํ†ตํ•ด ํ™•๋ณดํ•˜๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. ๊ณ ๋กœ ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง์„ ์น˜ํ™˜ํ•  ๊ฒฝ์šฐ ๊ฒฝํ™”์ฒด ๋‚ด๋ถ€์˜ ์กฐ์ง์ด ์น˜๋ฐ€ํ•˜๊ฒŒ ๋˜์–ด ๋ชจ์„ธ๊ด€๊ณต๊ทน์˜ ์šฉ์ ์ด ๊ฐ์†Œํ•จ์— ๋”ฐ๋ผ ๋™ ๊ฒฐ์œตํ•ด ์ €ํ•ญ์„ฑ๋Šฅ์ด ํ–ฅ์ƒ๋˜๋Š” ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

๊ฐ์‚ฌ์˜ ๊ธ€

๋ณธ ์—ฐ๊ตฌ๋Š” ๊ต์œก๊ณผํ•™๊ธฐ์ˆ ๋ถ€์™€ ํ•œ๊ตญ์—ฐ๊ตฌ์žฌ๋‹จ์˜ ์ง€์—ญํ˜์‹ ์ธ ๋ ฅ์–‘์„ฑ์‚ฌ์—…(2012H1B8A2025606)์œผ๋กœ ์ˆ˜ํ–‰๋œ ์—ฐ๊ตฌ๊ฒฐ๊ณผ์ž„. ์ด์— ๊ฐ์‚ฌ๋“œ๋ฆฝ๋‹ˆ๋‹ค.

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