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Journal of the Korea Concrete Institute

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




๋ณตํ•ฉ์žฌ๋ฃŒ, ์••์ถ•๊ฐ•๋„, ์—ฐ์„ฑ, ์ธ์žฅ๊ฑฐ๋™, ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ
Cementless composite, Compressive strength, Ductility, Tensile behavior, UHPC

1. ์„œ ๋ก 

์ตœ๊ทผ ์‚ฌํšŒ์  ์š”๊ตฌ์— ๋”ฐ๋ผ ๊ตฌ์กฐ๋ฌผ์ด ๋Œ€ํ˜•ํ™”๋˜๊ณ  ๊ณ ์„ฑ๋Šฅํ™” ๋จ์— ๋”ฐ๋ผ ๋ณด๋‹ค ์•ˆ์ „ํ•˜๊ณ  ํšจ์œจ์ ์ธ ๊ตฌ์กฐ์‹œ์Šคํ…œ์˜ ๊ฐœ๋ฐœ์ด ์š” ๊ตฌ๋˜๊ณ  ์žˆ๋‹ค. ๋˜ํ•œ ๋™์‹œ์— ์ „ํ†ต์ ์ธ ์ฝ˜ํฌ๋ฆฌํŠธ๋ณด๋‹ค ์šฐ์ˆ˜ํ•œ ์„ฑ ๋Šฅ์„ ๋‚˜ํƒ€๋‚ด๋Š” ๊ณ ์„ฑ๋Šฅ ๊ฑด์„ค์žฌ๋ฃŒ์— ๋Œ€ํ•œ ์š”๊ตฌ๊ฐ€ ๋†’์•„์ง€๊ณ  ์žˆ ์œผ๋ฉฐ, ์ด๋ฅผ ๊ฐœ๋ฐœํ•˜๊ธฐ ์œ„ํ•œ ์—ฐ๊ตฌ๊ฐ€ ํ™œ๋ฐœํžˆ ์ง„ํ–‰๋˜๊ณ  ์žˆ๋‹ค. ์ดˆ๊ณ  ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ(UHPC: ultra-high performance concrete)์™€ ๊ณ  ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ(high ductile fiber reinforced composite) ๋Š” ๋Œ€ํ‘œ์ ์ธ ๊ณ ์„ฑ๋Šฅ ๊ฑด์„ค์žฌ๋ฃŒ๋กœ ๋ถ„๋ฅ˜๋˜๊ณ  ์žˆ๋‹ค.

์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” 150 MPa ์ด์ƒ์˜ ๋†’์€ ์••์ถ•๊ฐ•๋„๋ฅผ ๊ฐ– ์œผ๋ฉด์„œ, ์ธ์žฅํ•˜์ค‘ ํ•˜์—์„œ ์ทจ์„ฑ์ ์ธ ๊ฑฐ๋™์„ ๋ง‰๊ธฐ ์œ„ํ•ด ์ ์ ˆํ•œ ์–‘์˜ ์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•˜๊ณ  ์ธ์žฅ๊ฐ•๋„๊ฐ€ 5 MPa ์ด์ƒ์„ ๋‚˜ํƒ€๋‚ด๋Š” ์žฌ ๋ฃŒ๋กœ ์ •์˜๋œ๋‹ค (AFGC, 2002; Russel and Graybeal, 2013). ์ด ๋Ÿฌํ•œ ๋†’์€ ์—ญํ•™์„ฑ๋Šฅ์€ 0.25 ์ดํ•˜์˜ ๋‚ฎ์€ ๋ฌผ/๊ฒฐํ•ฉ์žฌ๋น„๋ฅผ ๊ฐ–์ง€ ๋งŒ ๊ณ ์ฒด ํ˜ผํ•ฉ๋ฌผ๋“ค์˜ ์ž…๋„๋ฅผ ์ตœ์ ํ™”ํ•˜์—ฌ ์ถฉ์ง„๋ฐ€๋„๋ฅผ ๋†’์ด๊ณ  ๊ณ ์„ฑ๋Šฅ ๊ฐ์ˆ˜์ œ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ๋†’์€ ์œ ๋™ํŠน์„ฑ์„ ๊ฐ–์œผ๋ฉด์„œ ์žฌ๋ฃŒ๋ฅผ ๋ฐ€์‹คํ•˜๊ฒŒ ํ•จ์œผ๋กœ์จ ๋‚˜ํƒ€๋‚œ๋‹ค. ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์— ์‚ฌ์šฉ๋˜๋Š” ์„ฌ์œ ๋Š” ์ฃผ๋กœ ์ˆ˜๋ฐฑ ๋งˆ์ดํฌ๋กœ๋ฏธํ„ฐ์˜ ์ง๊ฒฝ์„ ๊ฐ–๋Š” ๊ณ ๊ฐ•๋„ ๊ฐ•์„ฌ ์œ ์ด๋ฉฐ, ์ผ๋ฐ˜์ ์œผ๋กœ ๋ถ€ํ”ผ๋น„๋กœ 1.5%์—์„œ 2.0%๊ฐ€ ์„ฌ์œ ๊ฐ€ ํ˜ผ์ž… ๋œ๋‹ค(Koh et al., 2013).

๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ๋Š” ์‹œ๋ฉ˜ํŠธ๊ณ„ ๊ฒฐํ•ฉ์žฌ ๊ธฐ๋ฐ˜ ํŽ˜์ด์Šค ํŠธ ๋˜๋Š” ๋ชจ๋ฅดํƒ€๋ฅด์— ๋ถ€ํ”ผ๋น„๋กœ ์•ฝ 2%์˜ ์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•˜์—ฌ ์ผ์ถ• ์ธ์žฅํ•˜์—์„œ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ(๋˜๋Š” ์—ฐ์„ฑ)์ด 3% ์ด์ƒ ๋‚˜ํƒ€๋‚˜๋Š” ๋ณต ํ•ฉ์žฌ๋ฃŒ์ด๋‹ค. ์ผ๋ณธํ† ๋ชฉํ•™ํšŒ์—์„œ๋Š” ์ด๋Ÿฌํ•œ ์žฌ๋ฃŒ๋ฅผ ๊ณ ์„ฑ๋Šฅ ์„ฌ์œ  ๋ณด๊ฐ• ์‹œ๋ฉ˜ํŠธ ๋ณตํ•ฉ์žฌ๋ฃŒ(HPFRCC: high performance fiber reinforced cement composite)๋กœ ๋ถ„๋ฅ˜ํ•˜๊ณ  ์žˆ์œผ๋ฉฐ, ๋ฏธ์‹œ๊ฐ„๋Œ€ํ•™ ๊ต์—์„œ ๊ฐœ๋ฐœํ•œ ECC(Engineered Cementitious Composite)๋Š” ๋Œ€ํ‘œ์ ์ธ ๊ณ ์„ฑ๋Šฅ ์„ฌ์œ ๋ณด๊ฐ• ์‹œ๋ฉ˜ํŠธ ๋ณตํ•ฉ์žฌ๋ฃŒ์ด๋‹ค (Maalej and Li, 1994; Li et al., 2001; JSCE, 2008). ์ตœ๊ทผ ์žฌ๋ฃŒ์  ์นœํ™˜๊ฒฝ์„ฑ ์„ ๋†’์ด๊ธฐ ์œ„ํ•˜์—ฌ ์‹œ๋ฉ˜ํŠธ๋ฅผ ์ „ํ˜€ ์‚ฌ์šฉํ•˜์ง€ ์•Š๊ณ  ์•Œ์นผ๋ฆฌ ํ™œ์„ฑ ํ™”์ œ๋ฅผ ์ด์šฉํ•˜์—ฌ ํ™œ์„ฑํ™” ์‹œํ‚จ ์Šฌ๋ž˜๊ทธ๋‚˜ ์ง€์˜คํด๋ฆฌ๋จธ๋ฅผ ์‚ฌ์šฉํ•˜ ์—ฌ ๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ๋ฅผ ๊ฐœ๋ฐœํ•œ ์—ฐ๊ตฌ๊ฐ€ ์ˆ˜ํ–‰๋˜์—ˆ๋‹ค (Lee et al., 2012; Ohno and Li, 2014; Nematollahi et al., 2015; Choi et al., 2016).

์ด์™€ ๊ฐ™์ด ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ ๋Š” ์ˆ˜ํ™”๋ฐ˜์‘์„ ํ•˜๋Š” ๊ฒฐํ•ฉ์žฌ ๊ธฐ๋ฐ˜ ํŽ˜์ด์ŠคํŠธ ๋˜๋Š” ๋ชจ๋ฅดํƒ€๋ฅด์— ๋น„์Šทํ•œ ์–‘์˜ ์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•œ๋‹ค๋Š” ์žฌ๋ฃŒ์  ์ธก๋ฉด์—์„œ ์œ ์‚ฌํ•˜์ง€ ๋งŒ, ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ๊ฐ€ ๋†’์€ ๊ฐ•๋„๋ฅผ ๋‚˜ํƒ€๋‚ด๋Š” ๋ฐ˜๋ฉด ์—ฐ์„ฑ์ด ๋‚ฎ์€ ํŠน์ง•์„ ๊ฐ–๊ณ , ๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ๋Š” ์—ฐ์„ฑ์ด ๋†’์ง€ ๋งŒ ๊ฐ•๋„๋Š” ์ƒ๋Œ€์ ์œผ๋กœ ๋‚ฎ์€ ํŠน์ง•์„ ๊ฐ–๊ณ  ์žˆ๋‹ค๋Š” ์ธก๋ฉด์—์„œ ์ฐจ ์ด์ ์ด ์žˆ๋‹ค. ์ด์— ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ๋‘ ๊ฐ€์ง€ ๋Œ€ํ‘œ์ ์ธ ๊ณ ์„ฑ๋Šฅ ๊ฑด ์„ค์žฌ๋ฃŒ์ธ ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ์˜ ์„ฑ๋Šฅ์„ ์‹คํ—˜์ ์œผ๋กœ ๋น„๊ตํ•˜๊ณ ์ž ํ•œ๋‹ค.

2. ์‹คํ—˜ ์žฌ๋ฃŒ ๋ฐ ๋ฐฉ๋ฒ•

2.1. ์‹คํ—˜ ์žฌ๋ฃŒ ๋ฐ ๋ฐฐํ•ฉ

์ด ์—ฐ๊ตฌ์—์„œ ์‚ฌ์šฉํ•œ ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ํ•œ๊ตญ์—์„œ ๊ฐœ๋ฐœ๋œ K-UHPC๋กœ ์•Œ๋ ค์ง„ ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ(S-UHPC ๋ฐฐํ•ฉ)๋กœ์„œ ์‚ฌ์šฉ ์žฌ๋ฃŒ ๋ฐ ๋ฐฐํ•ฉ์€ Table 1๊ณผ ๊ฐ™๋‹ค (Koh et al. 2013). ๊ฒฐํ•ฉ์žฌ ๋Š” 1์ข… ๋ณดํ†ตํฌํ‹€๋žœ๋“œ์‹œ๋ฉ˜ํŠธ์™€ ์ง€๋ฅด์ฝ”๋‹ˆ์›€ ์‹ค๋ฆฌ์นด์ด๋ฉฐ, ์‹œ๋ฉ˜ ํŠธ์™€ ์ง€๋ฅด์ฝ”๋‹ˆ์›€ ์‹ค๋ฆฌ์นด์˜ ๋น„์œจ์€ ์ค‘๋Ÿ‰๋น„๋กœ 1๋Œ€ 0.2์ด๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ ์‚ฌ์šฉํ•œ ์ง€๋ฅด์ฝ”๋‹ˆ์›€ ์‹ค๋ฆฌ์นด๋Š” ์‚ฐํ™”๊ทœ์†Œ๊ฐ€ 96% ์ด์ƒ ์ด๋ฉฐ ์‹ค๋ฆฌ์นดํ“ธ๊ณผ ํ™”ํ•™์„ฑ๋ถ„์€ ์œ ์‚ฌํ•˜์ง€๋งŒ ๋ถ„๋ง๋„ 80,000 cm2/g ์ •๋„์ด๋‹ค. ์ง€๋ฅด์ฝ”๋‹ˆ์›€ ์‹ค๋ฆฌ์นด๋Š” ๊ณต๊ทน ์ถฉ์ „ ํšจ๊ณผ์™€ ํฌ์กธ ๋ž€ ๋ฐ˜์‘์„ ํ†ตํ•˜์—ฌ ์žฌ๋ฃŒ์˜ ๋ฐ€๋„๋ฅผ ํ–ฅ์ƒ์‹œ์ผœ ๊ฐ•๋„๋ฅผ ์ฆ์ง„์‹œํ‚ค ๊ณ , ์ž…์ž ์ถฉ์ „๋ฐ€๋„๋ฅผ ์ฆ๊ฐ€์‹œํ‚ค๋ฉด์„œ ์œ ๋™์„ฑ์„ ํ–ฅ์ƒ์‹œํ‚ค๊ธฐ ์œ„ ํ•ด ์‚ฌ์šฉ๋˜์—ˆ๋‹ค. ์ถฉ์ „์žฌ๋Š” ์‚ฐํ™”๊ทœ์†Œ ์„ฑ๋ถ„์ด 99% ์ด์ƒ์ธ ์žฌ๋ฃŒ ๋กœ์„œ ๋ฐ€๋„๋Š” 2.60 g/cm3์ด๋ฉฐ, ํฌ๊ธฐ๋Š” ์‹œ๋ฉ˜ํŠธ์™€ ์ง€๋ฅด์ฝ”๋‹ˆ์›€ ์‹ค ๋ฆฌ์นด์˜ ์ค‘๊ฐ„ ์ •๋„์ธ ํ‰๊ท  ์ž…๊ฒฝ์ด 2.2 ใŽ›์˜ ํฌ๊ธฐ๋ฅผ ๊ฐ–๊ณ  ์žˆ๋‹ค. ์ถฉ์ „์žฌ๋Š” ์‹œ๋ฉ˜ํŠธ์™€ ์ง€๋ฅด์ฝ”๋‹ˆ์›€ ์‹ค๋ฆฌ์นด ์‚ฌ์ด๋ฅผ ์ฑ„์šฐ๋Š” ์—ญํ• ์„ ํ†ตํ•ด ์ถฉ์ „๋ฐ€๋„๋ฅผ ์ฆ๊ฐ€์‹œ์ผœ ์œ ๋™์„ฑ์„ ํ–ฅ์ƒ์‹œํ‚ค๊ณ , ๊ฒฝํ™” ํ›„์— ๋Š” ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ๋ฅผ ๋ฐ€์‹คํ•˜๊ฒŒ ํ•จ์œผ๋กœ์จ ๊ฐ•๋„ ์ฆ์ง„ ๋ฐ ๋‚ด ๊ตฌ์„ฑ์„ ํ–ฅ์ƒ์‹œํ‚ค๊ธฐ ์œ„ํ•ด ์‚ฌ์šฉ๋˜์—ˆ๋‹ค. ๊ทœ์‚ฌ๋Š” ๋ฐ€๋„ 2.62 g/cm3 ์ด๊ณ  ํ‰๊ท  ์ž…๊ฒฝ์ด 0.5 mm์ธ ๊ฒƒ์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ํ˜ผํ™”์ œ๋กœ๋Š” ํŒฝ ์ฐฝ์ œ, ์ˆ˜์ถ•์ €๊ฐ์ œ, ๊ณ ์„ฑ๋Šฅ๊ฐ์ˆ˜์ œ, ์†Œํฌ์ œ๊ฐ€ ์‚ฌ์šฉ๋˜์—ˆ๋‹ค.

Table 1

Materials and mixture proportions

Mixture Binder Water Filler Silica sand EAa SRAb HRWRAc Defoamer Fiber [vol.%]


Type weight Steel PE

S-UHPC Cement and zirconium 1 0.20 0.24 0.88 0.06 0.008 0.0184 0.0006 1.50 -
PE-AAS Alkali-activated slag 1 0.32 - - - - 0.004 0.001 - 1.75
AAS Alkali-activated slag 1 0.32 - - - - 0.002 0.001 - -

a Expansive agent

b Shrinkage reduction admixture

c High range water reduction agent

์ด ์—ฐ๊ตฌ์—์„œ ๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ(PE-AAS ๋ฐฐํ•ฉ)๋ฅผ ์ œ์กฐํ•˜๊ธฐ ์œ„ํ•ด ์‚ฌ์šฉํ•œ ๊ฒฐํ•ฉ์žฌ๋Š” ์•Œ์นผ๋ฆฌ ํ™œ์„ฑ ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ๋กœ์„œ ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ๋Š” 3์ข… ๋ถ„๋ง๋„(4,030 cm2/g)์ด๋ฉฐ, ๋น„์ค‘์€ 2.91์ด๋‹ค. ํ™œ์„ฑํ™”์ œ๋กœ๋Š” ๋ถ„๋งํ˜•์˜ ์ˆ˜์‚ฐํ™”์นผ์Š˜๊ณผ ํ™ฉ์‚ฐ๋‚˜ํŠธ๋ฅจ์ด ์‚ฌ์šฉ๋˜ ์—ˆ๊ณ , ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ, ์ˆ˜์‚ฐํ™”์นผ์Š˜, ํ™ฉ์‚ฐ๋‚˜ํŠธ๋ฅจ์˜ ๋น„์œจ์€ 1 : 0.084 : 0.034์ด๋‹ค. ํด๋ฆฌ์—ํ‹ธ๋ Œ ์„ฌ์œ ์˜ ๋ณด๊ฐ• ํšจ๊ณผ๋ฅผ ํ™•์ธํ•˜๊ธฐ ์œ„ํ•ด ๋น„๊ต ๋ฐฐํ•ฉ์œผ๋กœ ์‚ฌ์šฉํ•œ AAS ๋ฐฐํ•ฉ์€ PE-AAS์™€ ์„ฌ์œ ๋ฅผ ์ œ์™ธํ•˜ ๊ณ  ๋™์ผํ•œ ๋ฐฐํ•ฉ์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์—๋Š” ๊ฐ•์„ฌ์œ ๊ฐ€ ์‚ฌ์šฉ๋˜์—ˆ๊ณ , ์•Œ์นผ๋ฆฌ ํ™œ์„ฑ ์Šฌ๋ž˜๊ทธ ๊ธฐ๋ฐ˜ ๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ์—๋Š” ํด๋ฆฌ์—ํ‹ธ๋ Œ(PE) ์„ฌ์œ ๊ฐ€ ์‚ฌ์šฉ๋˜์—ˆ๋‹ค. ๊ฐ•์„ฌ์œ ์™€ ํด๋ฆฌ์—ํ‹ธ๋ Œ ์„ฌ์œ ์˜ ์น˜์ˆ˜ ๋ฐ ์„ฑ ์งˆ์€ Table 2์™€ ๊ฐ™๋‹ค.

Table 2

Properties of fibers

Fiber Diameter [ฮผm] Length [mm] Tensile strength [MPa] Density [g/cm3] Elastic modulus [GPa]

Steel 200 19.5 2,500 7.5 200
PE 12 18 2,700 0.97 88

2.2. ํ˜ผํ•ฉ ๋ฐฉ๋ฒ• ๋ฐ ์–‘์ƒ

์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ๋ฅผ ์ œ์กฐํ•˜๊ธฐ ์œ„ํ•ด์„œ ๋จผ์ €, ๋ถ„๋งํ˜•์ธ ์‹œ ๋ฉ˜ํŠธ, ์ง€๋ฅด์ฝ”๋‹ˆ์›€ ์‹ค๋ฆฌ์นด, ์ถฉ์ „์žฌ, ๊ณจ์žฌ, ํŒฝ์ฐฝ์ œ, ์ˆ˜์ถ•์ €๊ฐ์ œ ๋ฅผ ํˆฌ์ž…ํ•œ ํ›„ ๋ถ„๋ง๋“ค์ด ๊ณ ๋ฃจ ์„ž์ผ ์ˆ˜ ์žˆ๋„๋ก ์•ฝ 90 rpm์˜ ์†๋„ ๋กœ 10๋ถ„ ๋™์•ˆ ๊ฑด๋น„๋น”์„ ํ•˜์˜€๋‹ค. ๋‹ค์Œ์œผ๋กœ ํ˜ผํ•ฉ๊ธฐ์˜ ํšŒ์ „์†๋„ ๋ฅผ ๋™์ผํ•˜๊ฒŒ ์œ ์ง€ํ•œ ์ƒํƒœ์—์„œ ๋ฐฐํ•ฉ์ˆ˜, ๊ณ ์„ฑ๋Šฅ ๊ฐ์ˆ˜์ œ, ์†Œํฌ์ œ ๋ฅผ ํˆฌ์ž…ํ•œ ํ›„ ์žฌ๋ฃŒ๋“ค์˜ ๋ฐ˜์‘์— ์˜ํ•ด ์œ ๋™์ด ์‹œ์ž‘๋  ๋•Œ๊นŒ์ง€ 3 ๋ถ„์—์„œ 5๋ถ„ ๋™์•ˆ ์ถ”๊ฐ€๋กœ ํ˜ผํ•ฉํ•˜์˜€๋‹ค. ์œ ๋™์ด ์‹œ์ž‘๋˜๋ฉด ํ˜ผํ•ฉ๊ธฐ ์˜ ํšŒ์ „์†๋„๋ฅผ 270 rpm์œผ๋กœ ์ฆ๊ฐ€ํ•˜์—ฌ 2๋ถ„์—์„œ 3๋ถ„ ๋™์•ˆ ํ˜ผํ•ฉ ํ•œ ํ›„, ์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ํšŒ์ „์†๋„๋ฅผ ๋‹ค์‹œ 90 rpm์œผ๋กœ ์ค„์ด๊ณ  ์„ฌ์œ ๋ฅผ ์‹ ์†ํ•˜๊ฒŒ ํˆฌ์ž…ํ•˜์˜€๋‹ค. ์ด ํ›„ ์ถฉ๋ถ„ํ•œ ์„ฌ์œ  ๋ถ„์‚ฐ ์„ฑ์ด ํ™•๋ณด๋  ์ˆ˜ ์žˆ๋„๋ก ํšŒ์ „์†๋„๋ฅผ ๋‹ค์‹œ 270 rpm์œผ๋กœ ์ฆ๊ฐ€์‹œ ์ผœ 2๋ถ„์—์„œ 5๋ถ„ ๋™์•ˆ ํ˜ผํ•ฉํ•œ ํ›„ ๊ท ์ผํ•œ ์„ฌ์œ  ๋ถ„์‚ฐ์„ฑ์ด ํ™•๋ณด๋˜ ์—ˆ๋‹ค๊ณ  ํŒ๋‹จ๋˜๋ฉด ๋งˆ์ง€๋ง‰์œผ๋กœ ๊ธฐํฌ๋ฅผ ์ œ๊ฑฐํ•˜๊ธฐ ์œ„ํ•ด ํšŒ์ „์†๋„ ๋ฅผ 90 rpm์œผ๋กœ ์ค„์—ฌ 1๋ถ„๊ฐ„ ํ˜ผํ•ฉํ•˜์˜€๋‹ค (KICT, 2014).

์•Œ์นผ๋ฆฌ ํ™œ์„ฑ ์Šฌ๋ž˜๊ทธ ๊ธฐ๋ฐ˜ ๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ๋ฅผ ์ œ ์กฐํ•˜๊ธฐ ์œ„ํ•ด์„œ ๋ถ„๋งํ˜• ์žฌ๋ฃŒ์ธ ๊ฒฐํ•ฉ์žฌ๋ฅผ ๋„ฃ๊ณ  1๋ถ„ ๋™์•ˆ ๊ฑด๋น„๋น” ์„ ์‹ค์‹œํ•˜๊ณ , ๋ฐฐํ•ฉ์ˆ˜๋ฅผ ํ˜ผ์ž…ํ•œ ํ›„ 1๋ถ„ ๋™์•ˆ ํ˜ผํ•ฉํ•˜๋ฉด์„œ ๊ณ ์„ฑ ๋Šฅ ๊ฐ์ˆ˜์ œ๋ฅผ ์ฒจ๊ฐ€ํ•˜์˜€๋‹ค. ์„ฌ์œ ๊ฐ€ ํ˜ผ์ž…๋˜์ง€ ์•Š๋Š” AAS ๋ฐฐํ•ฉ์€ ์ดํ›„ ์‹คํ—˜์ฒด๋ฅผ ์ œ์กฐํ•˜์˜€๊ณ , ์„ฌ์œ ๊ฐ€ ํ˜ผ์ž…๋˜๋Š” PE-AAS ๋ฐฐํ•ฉ์€ ๋งคํŠธ๋ฆญ์Šค๊ฐ€ ๊ท ์ผํ•˜๊ฒŒ ํ˜ผํ•ฉ๋œ ํ›„ ํด๋ฆฌ์—ํ‹ธ๋ Œ์„ฌ์œ ๋ฅผ 1๋ถ„์— ๊ฑธ ์ณ ์กฐ๊ธˆ์”ฉ ๋„ฃ๊ณ  4๋ถ„ ๋™์•ˆ ํ˜ผํ•ฉํ•˜์˜€๋‹ค.

ํ˜ผํ•ฉ์ด ์™„๋ฃŒ๋œ ํ›„ ๋ฐ€๋„ ๋ฐ ์••์ถ•๊ฐ•๋„์™€ ์ผ์ถ• ์ธ์žฅ ์‹คํ—˜์„ ์œ„ ํ•œ ์‹œํŽธ์„ ์ œ์ž‘ํ•˜์—ฌ (23 ยฑ 3)ยฐC์™€ ์ƒ๋Œ€์Šต๋„ (60 ยฑ 10)% ์กฐ๊ฑด์— ์„œ ์–‘์ƒํ•˜๊ณ , ํƒ€์„ค 2์ผ ํ›„ ํƒˆํ˜•ํ•˜์—ฌ ์žฌ๋ น 28์ผ๊นŒ์ง€ ์–‘์ƒ์˜จ๋„ (23 ยฑ 3)ยฐC์˜ ์–‘์ƒ ์ˆ˜์กฐ์—์„œ ์ˆ˜์ค‘์–‘์ƒ์„ ์‹ค์‹œํ•˜์˜€๋‹ค.

2.3. ์‹คํ—˜ ๋ฐฉ๋ฒ•

๋ฐ€๋„๋Š” ํ˜ผํ•ฉ๊ณผ์ •์—์„œ ์˜๋„ํ•˜์ง€ ์•Š์€ ๊ณผ๋„ํ•œ ๊ธฐํฌ๊ฐ€ ์ƒ์„ฑ๋˜ ๋Š”๊ฐ€๋ฅผ ํ™•์ธํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๊ฐ ๋ฐฐํ•ฉ๋ณ„๋กœ 3๊ฐœ์”ฉ ์ œ์ž‘ํ•œ 50 mm ์ž… ๋ฐฉ ์‹คํ—˜์ฒด๋ฅผ ์ด์šฉํ•˜์—ฌ ๊ณต๊ธฐ ์ค‘ ๋ฌด๊ฒŒ์™€ ์ˆ˜์ค‘ ๋ฌด๊ฒŒ๋ฅผ ์ธก์ •ํ•˜์—ฌ ๋‹ค์Œ ์‹ (3)๊ณผ ๊ฐ™์ด ๊ณ„์‚ฐํ•˜์˜€๋‹ค.(1)

(1)
ฯ = W a i r W a i r โˆ’ W w a t e r ร— ฯ w

์—ฌ๊ธฐ์„œ, ฯw๋Š” ๋ฌผ์˜ ๋ฐ€๋„์ด๊ณ , Wair์™€ Wwater๋Š” ๊ฐ๊ฐ ์ž…๋ฐฉ ์‹ค ํ—˜์ฒด์˜ ๊ณต๊ธฐ ์ค‘๊ณผ ์ˆ˜์ค‘์—์„œ์˜ ๋ฌด๊ฒŒ๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค.

์••์ถ•๊ฐ•๋„๋Š” ๋ฐ€๋„๋ฅผ ์ธก์ •ํ•œ ์‹œํ—˜์ฒด๋ฅผ ์ด์šฉํ•˜์—ฌ KS L 5105 ์— ๊ทœ์ •๋œ ๋ฐฉ๋ฒ•์— ๋”ฐ๋ผ ์ธก์ •ํ•˜์˜€์œผ๋ฉฐ ๊ฐ ๋ฐฐํ•ฉ๋‹น ์‹œํ—˜์ฒด์˜ ๊ฐœ ์ˆ˜๋Š” 3๊ฐœ์ด๋‹ค.

์ผ์ถ• ์ธ์žฅ ์‹คํ—˜์„ ํ†ตํ•ด ์„ฌ์œ  ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ์˜ ์ธ์žฅ์„ฑ๋Šฅ์„ ํ‰๊ฐ€ํ•˜์˜€๋‹ค. ์ผ๋ณธํ† ๋ชฉํ•™ํšŒ์—์„œ ์ œ์•ˆํ•œ ๋ฐฉ๋ฒ•์— ๋”ฐ๋ผ Fig. 1(a) ์™€ ๊ฐ™์€ ํ˜•ํƒœ์˜ ์‹คํ—˜์ฒด๋ฅผ ์ œ์ž‘ํ•œ ํ›„, 28์ผ ์žฌ๋ น์—์„œ ์ธ์žฅ์„ฑ๋Šฅ ์„ ํ‰๊ฐ€ํ•˜์˜€๋‹ค (JSCE, 2008). ์ธ์žฅ ์‹คํ—˜ ๊ฒฐ๊ณผ๋Š” ๋ฐ€๋„๋‚˜ ์••์ถ•๊ฐ• ๋„์— ๋น„ํ•ด ํด ๊ฐ€๋Šฅ์„ฑ์ด ์žˆ๊ธฐ ๋•Œ๋ฌธ์— ์‹คํ—˜์ฒด๋ฅผ ๊ฐ ๋ฐฐํ•ฉ๋ณ„๋กœ ์ด 6๊ฐœ์”ฉ ์ œ์ž‘ํ•˜์˜€๋‹ค. ์ง์ ‘์ธ์žฅ ์‹คํ—˜์€ ์ตœ๋Œ€์šฉ๋Ÿ‰ 2ํ†ค์˜ ์ธ์žฅ๊ฐ• ๋„ ์‹œํ—˜๊ธฐ์—์„œ 0.1 mm/min. ์†๋„์˜ ๋ณ€์œ„ ์ œ์–ด ๋ฐฉ์‹์œผ๋กœ ์ˆ˜ํ–‰ ํ•˜์˜€๋‹ค. ๋ณ€์œ„ ์ธก์ • ๋ฐฉ๋ฒ•์€ ์‹คํ—˜์ฒด์˜ ์ขŒ์šฐ ์ธก๋ฉด์— 20 mm ์šฉ๋Ÿ‰ ์˜ ๋ณ€์œ„๊ณ„๋ฅผ ๋ถ€์ฐฉํ•˜์—ฌ ์ธก์ •ํ•˜์˜€์œผ๋ฉฐ, ๋ณ€ํ˜•๋ฅ  ํ™˜์‚ฐ์„ ์œ„ํ•œ ์ธก ์ •๊ธธ์ด๋Š” 80 mm์ด๋‹ค. ์ธก์ •๊ตฌ๊ฐ„ ๋‚ด์˜ ๋‹จ๋ฉด์€ S-UHPC ๋ฐฐํ•ฉ์˜ ๊ฒฝ ์šฐ 30 mm ร— 30 mm์ด๊ณ , PE-AAS ๋ฐฐํ•ฉ๊ณผ AAS ๋ฐฐํ•ฉ์€ 30 mm ร— 13 mm๋กœ ์ผ์ •ํ•˜๋‹ค. Fig. 1(b)๋Š” ์ง์ ‘์ธ์žฅ ์‹คํ—˜ ๋ชจ์Šต์„ ๋‚˜ํƒ€๋‚ธ๋‹ค.

Fig. 1

Dimension of specimen and test setup

JKSMI-21-69_F1.jpg

3. ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

3.1. ๋ฐ€๋„

Fig. 2๋Š” ๊ฐ ๋ฐฐํ•ฉ์˜ ์ธก์ •๋œ ๋ฐ€๋„๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. ์˜ˆ์ƒ๋œ ๋ฐ”์™€ ๊ฐ™์ด S-UHPC ๋ฐฐํ•ฉ์˜ ๋ฐ€๋„๊ฐ€ ๊ฐ€์žฅ ํฌ๊ฒŒ ์ธก์ •์ด ๋˜์—ˆ์œผ๋ฉฐ ๋ฐ€ ๋„๊ฐ€ ๋‚ฎ์€ ํด๋ฆฌ์—ํ‹ธ๋ Œ์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•œ PE-AAS ๋ฐฐํ•ฉ์˜ ๋ฐ€๋„๊ฐ€ ๊ฐ€์žฅ ๋‚ฎ๊ฒŒ ์ธก์ •๋˜์—ˆ๋‹ค. ์ด๋ก ์  ๋ฐ€๋„๋Š” ๊ฐ ์žฌ๋ฃŒ์˜ ๋ฐ€๋„์™€ ๋ฐฐํ•ฉ ์œผ๋กœ๋ถ€ํ„ฐ ๊ณ„์‚ฐํ•˜์˜€๋Š”๋ฐ ๋ชจ๋“  ๋ฐฐํ•ฉ์˜ ์ธก์ •๋œ ๋ฐ€๋„์™€ ์ด๋ก ์  ๋ฐ€๋„์˜ ์ฐจ์ด๋Š” 0.6% ์ดํ•˜๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด๋Ÿฌํ•œ ์‹คํ—˜ ๊ฒฐ๊ณผ๋กœ๋ถ€ ํ„ฐ ์ด ์—ฐ๊ตฌ์—์„œ ์ œ์กฐํ•œ ์‹คํ—˜์ฒด๋“ค์ด ์‹คํ—˜์ฒด๋ฅผ ์ œ์กฐํ•˜๋Š” ๋™์•ˆ ์˜๋„ํ•˜์ง€ ์•Š์€ ๊ธฐํฌ๋“ค์ด ์ƒ์„ฑ๋˜์ง€ ์•Š๊ณ  ๋ฐ€์‹คํ•˜๊ฒŒ ๋งŒ๋“ค์–ด์ง„ ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค.

Fig. 2

Density

JKSMI-21-69_F2.jpg

3.2. ์••์ถ•๊ฐ•๋„

Fig. 3์€ ๊ฐ ๋ฐฐํ•ฉ๋ณ„ ์••์ถ•๊ฐ•๋„ ์ธก์ • ๊ฒฐ๊ณผ๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. S-UHPC ๋ฐฐํ•ฉ์˜ ์••์ถ•๊ฐ•๋„๋Š” 155 MPa๋กœ ๋‚˜ํƒ€๋‚˜, 150 MPa ์ด์ƒ์„ ์š”๊ตฌ ํ•˜๋Š” UHPC์˜ ์„ฑ๋Šฅ์„ ๋งŒ์กฑํ•˜์˜€๋‹ค. ๊ณ ์˜จ ์–‘์ƒ์„ ํ•˜๋ฉด ์ด๋ณด๋‹ค ๋” ๋†’์€ ์••์ถ•๊ฐ•๋„๊ฐ€ ๋‚˜ํƒ€๋‚  ๊ฒƒ์œผ๋กœ ์˜ˆ์ƒ๋œ๋‹ค. PE-AAS ๋ฐฐํ•ฉ ์€ 32.9 MPa์˜ ์••์ถ•๊ฐ•๋„๊ฐ€ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, S-UHPC ๋ฐฐํ•ฉ์— ๋น„ํ•˜ ์—ฌ 21.2% ์ˆ˜์ค€์œผ๋กœ ๋‚˜ํƒ€๋‚˜ ๋‘ ๋ฐฐํ•ฉ์˜ ์••์ถ•๊ฐ•๋„์—๋Š” ํฐ ์ฐจ์ด๊ฐ€ ์žˆ๋Š” ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•˜์ง€ ์•Š์€ AAS ๋ฐฐํ•ฉ์˜ ๊ฒฝ ์šฐ PE-AAS ๋ฐฐํ•ฉ๊ณผ ๋น„๊ตํ•˜์—ฌ ์•ฝ 3% ์ •๋„ ์ฐจ์ด๊ฐ€ ๋ฐœ์ƒํ•˜์—ฌ ํด ๋ฆฌ์—ํ‹ธ๋ Œ์„ฌ์œ ์˜ ํ˜ผ์ž…์— ์˜ํ•œ ์˜ํ–ฅ์ด ๊ฑฐ์˜ ์—†๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€ ๋‚ฌ๋‹ค.

Fig. 3

Compressive strength

JKSMI-21-69_F3.jpg

3.3. ์ธ์žฅ๊ฑฐ๋™

Fig. 4๋Š” ๊ฐ ๋ฐฐํ•ฉ๋ณ„ ์ธ์žฅ์‘๋ ฅ๊ณผ ๋ณ€ํ˜•๋ฅ  ๊ทธ๋ž˜ํ”„๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. ์„ฌ์œ ๊ฐ€ ๋“ค์–ด๊ฐ„ S-UHPC ๋ฐฐํ•ฉ๊ณผ PE-AAS ๋ฐฐํ•ฉ์˜ ๊ฒฝ์šฐ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๋ฐœ์ƒ ์ดํ›„ ๋ณ€ํ˜•๋ฅ  ๊ฒฝํ™”๊ฑฐ๋™์ด ๋‚˜ํƒ€๋‚ฌ๋‹ค. S-UHPC ๋ฐฐํ•ฉ๊ณผ PE-AAS ๋ฐฐํ•ฉ ๋ชจ๋‘ ๋ณ€ํ˜•๋ฅ  ๊ฒฝํ™”๊ฑฐ๋™์ด ๋‚˜ํƒ€๋‚ฌ์ง€๋งŒ ์ „์ฒด์ ์ธ ๊ฑฐ๋™์—๋Š” ํฐ ์ฐจ์ด๊ฐ€ ๋ฐœ์ƒํ•˜์˜€๋‹ค. S-UHPC ๋ฐฐํ•ฉ์€ PE-AAS ๋ฐฐ ํ•ฉ์— ๋น„ํ•˜์—ฌ ๋†’์€ ๊ท ์—ด๊ฐ•๋„์™€ ๋†’์€ ์ธ์žฅ๊ฐ•๋„๊ฐ€ ๋‚˜ํƒ€๋‚œ ๋ฐ˜๋ฉด ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ์€ ๋‚ฎ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์„ฌ์œ ๊ฐ€ ํ˜ผ์ž…๋˜์ง€ ์•Š์€ AAS ๋ฐฐํ•ฉ์˜ ๊ฒฝ์šฐ ์ผ๋ฐ˜์ ์ธ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ๊ฐ™์ด ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๋ฐœ์ƒ ์ด ํ›„ ๊ธ‰๊ฒฉํ•œ ์‘๋ ฅ์ €ํ•˜๊ฐ€ ๋ฐœ์ƒํ•˜๋ฉด์„œ ํŒŒ๊ดด๋˜์—ˆ๋‹ค.

Fig. 4

Tensile stress and strain curves: (a) S-UHPC, (b) PE-AAS, and (c) AAS

JKSMI-21-69_F4.jpg

Fig. 5๋Š” ๊ฐ ๋ฐฐํ•ฉ๋ณ„ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„, ์ธ์žฅ๊ฐ•๋„, ๊ทธ๋ฆฌ๊ณ  ์ธ ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ์„ ๋„ํ‘œ๋กœ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. S-UHPC ๋ฐฐํ•ฉ์˜ ์ฒซ ๋ฒˆ ์งธ ๊ท ์—ด๊ฐ•๋„๋Š” 10.7 MPa๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. PE-AAS ๋ฐฐํ•ฉ์˜ ์ฒซ ๋ฒˆ ์งธ ๊ท ์—ด๊ฐ•๋„๋Š” 3.4 MPa์˜€์œผ๋ฉฐ, S-UHPC ๋ฐฐํ•ฉ์˜ 31.4% ์ˆ˜์ค€ ์ด๋‹ค. ๊ท ์—ด๊ฐ•๋„๋Š” ์••์ถ•๊ฐ•๋„์™€ ๋น„๋ก€ํ•˜๊ธฐ ๋•Œ๋ฌธ์— ์ด์™€ ๊ฐ™์€ ์ฐจ ์ด๊ฐ€ ๋ฐœ์ƒํ•˜์˜€๋‹ค. ์„ฌ์œ ๊ฐ€ ํ˜ผ์ž…๋˜์ง€ ์•Š์€ AAS ๋ฐฐํ•ฉ์˜ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„๋Š” PE-AAS ๋ฐฐํ•ฉ์˜ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„์™€ 1.9% ์ฐจ์ด๋งŒ ๋ฐœ์ƒํ•˜์—ฌ ๊ท ์—ด๊ฐ•๋„๋Š” ์„ฌ์œ ์˜ ์˜ํ–ฅ์ด ๊ฑฐ์˜ ์—†๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€ ๋‚ฌ๋‹ค.

Fig. 5

Tensile behavior: (a) first cracking strength, (b) tensile strength, and (c) tensile strain capacity

JKSMI-21-69_F5.jpg

S-UHPC ๋ฐฐํ•ฉ์˜ ์ธ์žฅ๊ฐ•๋„๋Š” 20.4 MPa๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. PEAAS ๋ฐฐํ•ฉ์˜ ์ธ์žฅ๊ฐ•๋„๋Š” 8.3 MPa๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, ์ด๋Š” S-UHPC ๋ฐฐํ•ฉ์˜ 40.4% ์ˆ˜์ค€์œผ๋กœ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„์˜ ์ฐจ์ด์— ๋น„ํ•˜์—ฌ 9.1% ๊ฐ์†Œ๋œ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์„ฌ์œ ๋ฅผ ๋ณด๊ฐ•ํ•˜๋Š” ๊ฒฝ์šฐ ์ธ์žฅ๊ฐ• ๋„๋Š” ๋งคํŠธ๋ฆญ์Šค์˜ ์„ฑ์งˆ์ด ์•„๋‹ˆ๋ผ ๊ท ์—ด๋ฉด์—์„œ ๋งคํŠธ๋ฆญ์Šค์™€ ์„ฌ์œ  ์‚ฌ์ด์˜ ์„ฌ์œ ๊ฐ€๊ต๊ฑฐ๋™์— ์˜ํ•ด ๊ฒฐ์ •๋˜๋ฉฐ, ์ธ์žฅ๊ฐ•๋„๋Š” ์ตœ๋Œ€ ์„ฌ ์œ ๊ฐ€๊ต์‘๋ ฅ๊ณผ ๊ฐ™๋‹ค. ์ด๋Ÿฌํ•œ ์‚ฌ์‹ค๋กœ๋ถ€ํ„ฐ S-UHPC ๋ฐฐํ•ฉ๊ณผ PE-AAS ๋ฐฐํ•ฉ ๋ชจ๋‘ ์ตœ๋Œ€ ์„ฌ์œ ๊ฐ€๊ต์‘๋ ฅ์ด ๋งคํŠธ๋ฆญ์Šค ๊ท ์—ด๊ฐ•๋„ ๋ณด๋‹ค ํฐ ๊ฒƒ์„ ๊ฐ„์ ‘์ ์œผ๋กœ ์•Œ ์ˆ˜ ์žˆ๋‹ค. AAS ๋ฐฐํ•ฉ์˜ ์ธ์žฅ๊ฐ•๋„๋Š” ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„์™€ ๋™์ผํ•˜์˜€์œผ๋ฉฐ, PE-AAS ๋ฐฐํ•ฉ๊ณผ ๋น„๊ตํ•˜๋ฉด 58.6% ๊ฐ์†Œ๋œ ๊ฒƒ์ด๋‹ค. ์ฆ‰, ํด๋ฆฌ์—ํ‹ธ๋ Œ์„ฌ์œ  ํ˜ผ์ž…์„ ํ†ตํ•˜์—ฌ ์ธ ์žฅ๊ฐ•๋„๋ฅผ 2.4๋ฐฐ ์ฆ๊ฐ€์‹œํ‚ฌ ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

S-UHPC ๋ฐฐํ•ฉ์˜ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ์€ 1.04%๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, ์ด ๋Š” ์ผ๋ฐ˜์ ์ธ ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ๊ณผ ์œ ์‚ฌํ•œ ๊ฐ’ ์ด๋‹ค. PE-AAS ๋ฐฐํ•ฉ์˜ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ์€ 7.89%๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, ์ด๋Š” S-UHPC ๋ฐฐํ•ฉ์— ๋น„ํ•˜์—ฌ7.62๋ฐฐ ๋†’์€ ๊ฐ’์ด๋‹ค. ์ข…ํ•ฉ์ ์œผ๋กœ PE-AAS ๋ฐฐํ•ฉ์ด S-UHPC ๋ฐฐํ•ฉ์— ๋น„ํ•˜์—ฌ ๊ฐ•๋„๋Š” ๋‚ฎ์ง€๋งŒ ๋‚ฎ์€ ๊ฐ•๋„์— ๋น„ํ•˜์—ฌ ํ›จ์”ฌ ํฐ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ์ด ๋‚˜ํƒ€๋‚ฌ๋‹ค. AAS ๋ฐฐํ•ฉ (0.02%)๊ณผ ๋น„๊ตํ•˜๋ฉด PE-AAS ๋ฐฐํ•ฉ์€ 394๋ฐฐ ๋†’์€ ์ธ์žฅ๋ณ€ํ˜•์„ฑ ๋Šฅ์„ ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

Fig. 6์€ ์••์ถ•๊ฐ•๋„(fcu) ๋Œ€๋น„ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„(f1st)์˜ ๋น„๋ฅผ ํƒ€ ๋‚ธ๋‹ค. ์ผ๋ฐ˜์ ์œผ๋กœ ๋ฌด๊ทผ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ธ์žฅ๊ฐ•๋„๊ฐ€ ์••์ถ•๊ฐ•๋„์˜ 10% ์ˆ˜์ค€์ธ๋ฐ ๋ฐ˜ํ•˜์—ฌ S-UHPC ๋ฐฐํ•ฉ์€ ์ด๋ณด๋‹ค ์ž‘๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์œผ ๋ฉฐ, PE-AAS ๋ฐฐํ•ฉ๊ณผ AAS ๋ฐฐํ•ฉ์€ ๊ฐ๊ฐ 10.2%์™€ 10.1%๋กœ ๋‚˜ํƒ€ ๋‚ฌ๋‹ค.

Fig. 6

Ratio of the first cracking strength to the compressive strength

JKSMI-21-69_F6.jpg

Fig. 7์€ ๊ฐ ๋ฐฐํ•ฉ๋ณ„ ์••์ถ•๊ฐ•๋„ ๋Œ€๋น„ ์ธ์žฅ๊ฐ•๋„(ft)์˜ ๋น„๋ฅผ ๋‚˜ํƒ€ ๋‚ธ๋‹ค. S-UHPC ๋ฐฐํ•ฉ์˜ ๊ฒฝ์šฐ ์••์ถ•๊ฐ•๋„ ๋Œ€๋น„ ์ธ์žฅ๊ฐ•๋„์˜ ๋น„๊ฐ€ 13.2%๋กœ ๋‚˜ํƒ€๋‚œ ๋ฐ˜๋ฉด PE-AAS ๋ฐฐํ•ฉ์€ ์••์ถ•๊ฐ•๋„ ๋Œ€๋น„ ์ธ์žฅ๊ฐ• ๋„์˜ ๋น„๊ฐ€ 25.1%๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. PE-AAS ๋ฐฐํ•ฉ์ด S-UHPC ๋ฐฐํ•ฉ ์— ๋น„ํ•˜์—ฌ ์••์ถ•๊ฐ•๋„, ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„, ์ธ์žฅ๊ฐ•๋„ ๋ชจ๋‘ ๋‚ฎ์ง€๋งŒ ์••์ถ•๊ฐ•๋„ ๋Œ€๋น„ ์ธ์žฅ๊ฐ•๋„๋Š” 12.0% ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด๋ฅผ ํ†ตํ•ด S-UHPC ๋ฐฐํ•ฉ์— ๋น„ํ•˜์—ฌ PE-AAS ๋ฐฐํ•ฉ์ด ์„ฌ์œ  ํ˜ผ์ž…์„ ํ†ตํ•˜์—ฌ ์ธ์žฅ์„ฑ๋Šฅ์„ ํ–ฅ์ƒ์‹œํ‚ค๋Š”๋ฐ ์ƒ๋Œ€์ ์œผ๋กœ ํšจ๊ณผ์ ์ž„์„ ์•Œ ์ˆ˜ ์žˆ ๋‹ค. AAS ๋ฐฐํ•ฉ์˜ ์••์ถ•๊ฐ•๋„ ๋Œ€๋น„ ์ธ์žฅ๊ฐ•๋„์˜ ๋น„๋Š” ์••์ถ•๊ฐ•๋„ ๋Œ€ ๋น„ ๊ท ์—ด๊ฐ•๋„์˜ ๋น„์™€ ๊ฐ™์€ 10.1%์˜€๋‹ค. ์ด๋Š” ์„ฌ์œ ๋ณด๊ฐ• ํšจ๊ณผ๊ฐ€ ์—†์—ˆ๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค.

Fig. 7

Ratio of the tensile strength to the compressive strength

JKSMI-21-69_F7.jpg

Fig. 8์€ ๊ฐ ๋ฐฐํ•ฉ๋ณ„ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„ ๋Œ€๋น„ ์ธ์žฅ๊ฐ•๋„์˜ ๋น„๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. S-UHPC ๋ฐฐํ•ฉ์˜ ๊ฒฝ์šฐ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„ ๋Œ€๋น„ ์ธ์žฅ ๊ฐ•๋„์˜ ๋น„๋Š” 1.9๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, PE-AAS ๋ฐฐํ•ฉ์€ 2.5๋กœ ๋‚˜ํƒ€๋‚ฌ ๋‹ค. AAS ๋ฐฐํ•ฉ์€ 1๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. Kanda and Li (2006)๋Š” ๋‹ค์ค‘ ๊ท  ์—ด์— ์˜ํ•œ ๋ณ€ํ˜•๋ฅ  ๊ฒฝํ™”๊ฑฐ๋™์ด ๋‚˜ํƒ€๋‚˜๊ธฐ ์œ„ํ•œ ์ง€ํ‘œ๋กœ์„œ ๊ฐ•๋„ ์ง€ํ‘œ์™€ ์—๋„ˆ์ง€ ์ง€ํ‘œ๋ฅผ ์ œ์‹œํ•˜์˜€๋‹ค. ๊ฐ•๋„ ์ง€ํ‘œ๋Š” ๋งคํŠธ๋ฆญ์Šค ๊ท  ์—ด๊ฐ•๋„ ๋Œ€๋น„ ์ตœ๋Œ€ ์„ฌ์œ ๊ฐ€๊ต์‘๋ ฅ์˜ ๋น„๋กœ ํ‘œํ˜„๋˜๋ฉฐ ์ด ๊ฐ’์ด ํด ์ˆ˜๋ก ๋‹ค์ค‘ ๊ท ์—ด์— ์˜ํ•œ ๋ณ€ํ˜•๋ฅ  ๊ฒฝํ™”๊ฑฐ๋™์ด ๋‚˜ํƒ€๋‚  ํ™•๋ฅ ์ด ์ปค ์ง€๊ฒŒ ๋˜๋ฉฐ, ์ตœ์†Œ 1๋ณด๋‹ค ์ปค์•ผํ•œ๋‹ค. ์ฆ‰, Fig. 8์€ ๊ฐ•๋„ ์ง€ํ‘œ๋ฅผ ๋‚˜ ํƒ€๋‚ด๋ฉฐ, ์ด ๊ฐ’์€ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ๊ณผ ๊ฐ•ํ•œ ์ƒ๊ด€๊ด€๊ณ„๋ฅผ ๊ฐ–๊ณ  ์žˆ๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ๋„ ๊ฐ•๋„ ์ง€ํ‘œ๊ฐ€ ๊ฐ€์žฅ ํฐ PE-AAS ๋ฐฐํ•ฉ์ด ๊ฐ€์žฅ ํฐ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ์„ ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

Fig. 8

Ratio of the tensile strength to the first cracking strength

JKSMI-21-69_F8.jpg

Fig. 9๋Š” ์ธ์žฅ์‘๋ ฅ๊ณผ ๋ณ€ํ˜•๋ฅ ์˜ ๋ฉด์ ์„ ๋‚˜ํƒ€๋‚ด๋Š” ์ธ์„ฑ์„ ๋‚˜ ํƒ€๋‚ด๋ฉฐ ์žฌ๋ฃŒ๊ฐ€ ํŒŒ๊ดด๋˜๋ฉด์„œ ํก์ˆ˜ํ•  ์ˆ˜ ์žˆ๋Š” ์—๋„ˆ์ง€๋ฅผ ์˜๋ฏธํ•œ ๋‹ค. ์ธ์„ฑ์„ ๊ณ„์‚ฐํ•  ๋•Œ ๊ธฐ์ค€ ๋ณ€ํ˜•๋ฅ ์€ ์ตœ๋Œ€ ์‘๋ ฅ์— ํ•ด๋‹นํ•˜๋Š” ๋ณ€ ํ˜•๋ฅ ๋กœ ํ•˜์˜€๋‹ค. PE-AAS ๋ฐฐํ•ฉ์ด S-UHPC ๋ฐฐํ•ฉ์— ๋น„ํ•˜์—ฌ ์ฒซ ๋ฒˆ์งธ ๊ท ์—ด๊ฐ•๋„์™€ ์ธ์žฅ๊ฐ•๋„๋Š” ๋‚ฎ์•˜์ง€๋งŒ, ์ธ์„ฑ์€ 2.8๋ฐฐ ๋†’์€ ๊ฒƒ ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. AAS ๋ฐฐํ•ฉ์˜ ์ธ์„ฑ์€ 0.0007 MPa m/m๋กœ PE-AAS ๋ฐฐํ•ฉ๊ณผ S-UHPC ๋ฐฐํ•ฉ์— ๋น„ํ•˜์—ฌ ๋งค์šฐ ๋‚ฎ์•˜๋‹ค. ์ฝ˜ํฌ๋ฆฌํŠธ ๊ตฌ์กฐ ๋ฌผ์„ ์„ค๊ณ„ํ•  ๋•Œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ธ์„ฑ์ด ๋งค์šฐ ๋‚ฎ๊ธฐ ๋•Œ๋ฌธ์— ์ธ์„ฑ์„ ์„ค๊ณ„์— ๋ฐ˜์˜ํ•˜์ง€ ์•Š์ง€๋งŒ, ์ด ์—ฐ๊ตฌ์—์„œ ์กฐ์‚ฌํ•œ ์žฌ๋ฃŒ์™€ ๊ฐ™์ด ๊ฐ• ๋„๋Š” ์ผ๋ฐ˜์ ์ธ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ์œ ์‚ฌํ•˜๋ฉด์„œ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ ๋ฐ ์ธ์„ฑ ์ด ํฐ ์žฌ๋ฃŒ๊ฐ€ ์‚ฌ์šฉ๋œ๋‹ค๋ฉด ์ง€์ง„๊ณผ ๊ฐ™์ด ํฐ ๋ณ€ํ˜•์ด ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ ๋Š” ํ•˜์ค‘์ด ์ž‘์šฉํ•  ๋•Œ ๊ตฌ์กฐ๋ฌผ์˜ ์„ฑ๋Šฅ์„ ํ–ฅ์ƒ์‹œํ‚ค๋Š”๋ฐ ๊ธฐ์—ฌํ•  ์ˆ˜ ์žˆ์„ ๊ฒƒ์œผ๋กœ ์ƒ๊ฐ๋œ๋‹ค.

Fig. 9

Toughness

JKSMI-21-69_F9.jpg

4. ๊ฒฐ ๋ก 

์ด ์—ฐ๊ตฌ์˜ ๋ชฉ์ ์€ ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ๊ณ ์—ฐ์„ฑ ์„ฌ์œ ๋ณด๊ฐ• ๋ณตํ•ฉ์žฌ๋ฃŒ์˜ ์„ฑ๋Šฅ์„ ๋น„๊ตํ•˜๋Š” ๊ฒƒ์ด๋‹ค. ์ด๋ฅผ ์œ„ํ•˜์—ฌ ๋ฐ€๋„, ์••์ถ• ๊ฐ•๋„, ์ธ์žฅ๊ฑฐ๋™, ์—๋„ˆ์ง€ ํก์ˆ˜ ๋Šฅ๋ ฅ์„ ์‹คํ—˜์ ์œผ๋กœ ์ธก์ •ํ•˜์˜€๋‹ค. ์‹คํ—˜๊ฒฐ๊ณผ๋กœ๋ถ€ํ„ฐ ๋‹ค์Œ๊ณผ ๊ฐ™์€ ๊ฒฐ๋ก ์„ ๋„์ถœํ•˜์˜€๋‹ค.

  • 1) ํด๋ฆฌ์—ํ‹ธ๋ Œ์„ฌ์œ  ๋ณด๊ฐ• ์•Œ์นผ๋ฆฌํ™œ์„ฑ ์Šฌ๋ž˜๊ทธ ๊ธฐ๋ฐ˜ ๋ณตํ•ฉ์žฌ ๋ฃŒ๋Š” ๊ฐ•์„ฌ์œ  ๋ณด๊ฐ• ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ๋น„๊ตํ•˜์—ฌ ๋‚ฎ์€ ์••์ถ•๊ฐ•๋„ ๋ฐ ์ธ์žฅ๊ฐ•๋„๋ฅผ ๋‚˜ํƒ€๋‚ด์ง€๋งŒ, ํด๋ฆฌ์—ํ‹ธ๋ Œ์„ฌ์œ  ๋ณด๊ฐ• ์•Œ์นผ๋ฆฌํ™œ์„ฑ ์Šฌ๋ž˜๊ทธ ๊ธฐ๋ฐ˜ ๋ณตํ•ฉ์žฌ๋ฃŒ๋Š” ๊ฐ•์„ฌ์œ  ๋ณด๊ฐ• ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ๋น„๊ตํ•˜์—ฌ ๋†’์€ ์ธ์žฅ๋ณ€ํ˜•์„ฑ๋Šฅ๊ณผ ์ธ์„ฑ์„ ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

  • 2) ์•Œ์นผ๋ฆฌ ํ™œ์„ฑ ์Šฌ๋ž˜๊ทธ ๊ธฐ๋ฐ˜ ๋ฌด์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ์— ํด๋ฆฌ์— ํ‹ธ๋ Œ์„ฌ์œ ๋ฅผ ๋ณด๊ฐ•ํ•˜์—ฌ 7.89%์— ์ด๋ฅด๋Š” ๋†’์€ ์ธ์žฅ๋ณ€ํ˜•์„ฑ ๋Šฅ์„ ํ™•๋ณดํ•˜๋Š” ๊ฒƒ์ด ๊ฐ€๋Šฅํ•œ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, ์ด๋Š” ์ดˆ ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ์„ฌ์œ ๋ฅผ ๋ณด๊ฐ•ํ•˜์ง€ ์•Š์€ ๋ฌด์‹œ๋ฉ˜ํŠธ ํŽ˜์ด ์ŠคํŠธ์— ๋น„ํ•˜์—ฌ ๊ฐ๊ฐ 7.62๋ฐฐ์™€ 394๋ฐฐ์— ๋‹ฌํ•˜๋Š” ์„ฑ๋Šฅ์ด๋‹ค.

  • 3) ์••์ถ•๊ฐ•๋„์™€ ์ธ์žฅ์‹คํ—˜๊ฒฐ๊ณผ ์•Œ์นผ๋ฆฌ ํ™œ์„ฑ ์Šฌ๋ž˜๊ทธ ๊ธฐ๋ฐ˜ ๋ฌด ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ์˜ ์••์ถ•๊ฐ•๋„ ๋ฐ ๊ท ์—ด๊ฐ•๋„์— ๋ฏธ์น˜๋Š” ํด ๋ฆฌ์—ํ‹ธ๋ Œ์„ฌ์œ ์˜ ์˜ํ–ฅ์€ 3.2% ์ด๋‚ด๋กœ ๋‚˜ํƒ€๋‚˜ ์˜ํ–ฅ์ด ํฌ ์ง€ ์•Š๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

  • 4) ๋ฐ€๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ชจ๋“  ๋ฐฐํ•ฉ์—์„œ ๊ณ„์ธกํ•œ ๋ฐ€๋„์™€ ์ด๋ก ์ ์œผ ๋กœ ๊ณ„์‚ฐํ•œ ๋ฐ€๋„์™€ ์ฐจ์ด๋Š” 0.6% ์ด๋‚ด๋กœ ๋‚˜ํƒ€๋‚˜ ์ด ์—ฐ๊ตฌ์— ์„œ ์‚ฌ์šฉํ•œ ๋ฐฉ์‹์œผ๋กœ ์ œ์กฐํ•  ๊ฒฝ์šฐ ์˜๋„ํ•˜์ง€ ์•Š์€ ํฐ ๊ธฐํฌ ๋“ฑ์ด ์ƒ์„ฑ๋˜์ง€ ์•Š๊ณ  ์ œ์กฐํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

๊ฐ์‚ฌ์˜ ๊ธ€

๋ณธ ๋…ผ๋ฌธ์€ ๊ตญํ† ๊ตํ†ต๋ถ€ ๊ตญํ† ๊ตํ†ต๊ธฐ์ˆ ์ด‰์ง„์—ฐ๊ตฌ์‚ฌ์—… โ€œ๋‚˜๋…ธ์ „ ๊ธฐ๋ฐฉ์‚ฌ๊ธฐ์ˆ ์„ ์œตํ•ฉํ•œ ๋“ฑ๊ฐ€๊ฐ์‡  10%๊ธ‰ ๋‹ค๊ธฐ๋Šฅ ๊ฑด์ถ•์žฌ๋ฃŒ ๋ฐ ๊ตฌ ์กฐ์‹œ์Šคํ…œ ๊ฐœ๋ฐœ(๊ณผ์ œ๋ฒˆํ˜ธ: 15CTAP-C097490-01)โ€์˜ ์—ฐ๊ตฌ๋น„์™€ ๊ตญํ† ๊ตํ†ต๋ถ€ ๊ตญํ† ๊ตํ†ต๊ธฐ์ˆ ์ง€์—ญํŠน์„ฑํ™”์‚ฌ์—… ์—ฐ๊ตฌ๊ฐœ๋ฐœ์‚ฌ์—…์˜ ์—ฐ ๊ตฌ๋น„์ง€์›(17RDRP-B076564-04)์— ์˜ํ•ด ์ˆ˜ํ–‰๋˜์—ˆ์Šต๋‹ˆ๋‹ค.

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