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์—ญํ•™์„ฑ๋Šฅ, ๋‚ด๊ตฌ์„ฑ๋Šฅ, ๋งˆ์ดํฌ๋กœ๊ฐ•์„ฌ์œ , ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ
mechanical characteristics, durability characteristics, micro steel fibers, latex modified concrete

  • 1. ์„œ    ๋ก 

  • 2. ์‹คํ—˜๊ณ„ํš ๋ฐ ๋ฐฉ๋ฒ•

  •   2.1 ์‚ฌ์šฉ ์žฌ๋ฃŒ

  •   2.2 ๋ฐฐํ•ฉ ์„ค๊ณ„

  •   2.3 ์‹คํ—˜ ๋ฐฉ๋ฒ•

  •   2.3.1 ์••์ถ•๊ฐ•๋„ ๋ฐ ํœจ๊ฐ•๋„ ์‹คํ—˜ ๋ฐฉ๋ฒ•

  •   2.3.2 ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜ ๋ฐฉ๋ฒ•

  •   2.3.3 ์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜ ๋ฐฉ๋ฒ•

  •   2.3.4 ๋™๊ฒฐ์œตํ•ด ์‹คํ—˜ ๋ฐฉ๋ฒ•

  • 3. ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-LMC์˜ ์—ญํ•™ ํŠน์„ฑ

  •   3.1 ์••์ถ•๊ฐ•๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

  •   3.2 ํœจ๊ฐ•๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

  •   3.3 ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

  • 4. ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-LMC์˜ ๋‚ด๊ตฌ์„ฑ๋Šฅ

  •   4.1 ์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

  •   4.2 ๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

  • 5. ๊ฒฐ    ๋ก 

1. ์„œ    ๋ก 

๊ตญ๋‚ด์˜ ์ฝ˜ํฌ๋ฆฌํŠธ ๋„๋กœ ๋ฐ ๋„๋กœ ์ฃผ๋ณ€ ์ฝ˜ํฌ๋ฆฌํŠธ ์†Œ๊ตฌ์กฐ๋ฌผ์€ ์ค‘์ฐจ๋Ÿ‰์— ์˜ํ•œ ํ”ผ๋กœ ๊ท ์—ด, ์ฝ˜ํฌ๋ฆฌํŠธ ๊ฑด์กฐ์ˆ˜์ถ•, ๋™๊ฒฐ์œตํ•ด ๋ฐ ๋น—๋ฌผ ์นจํˆฌ, ๊ฒจ์šธ์ฒ  ์Šต์—ผ์‹ ์ œ์„ค์ œ์˜ ์‚ฌ์šฉ ๋“ฑ์œผ๋กœ ์ธํ•ด ์ฝ˜ํฌ๋ฆฌํŠธ ์—ดํ™”๊ฐ€ ๋น ๋ฅด๊ฒŒ ๋ฐœ์ƒํ•˜๋Š” ์‹ค์ •์ด๋‹ค(Jeong et al. 2005). ๋„๋กœ ์ฃผ๋ณ€ ์†Œ๊ตฌ์กฐ๋ฌผ์˜ ํ•˜๋‚˜์ธ ์ฝ˜ํฌ๋ฆฌํŠธ ๋„๋กœ ์ธก๊ตฌ๋Š” ๋„๋กœ ๊ฐ€์žฅ์ž๋ฆฌ์— ์„ค์น˜๋˜์–ด ์ฐจ๋Ÿ‰์œผ๋กœ๋ถ€ํ„ฐ ๋ณดํ–‰์ž๋ฅผ ๋ณดํ˜ธํ•˜๊ณ  ๋„๋กœ ๋…ธ๋ฉด์— ๋ฐฐ์ˆ˜๋ฅผ ์ด‰์ง„์‹œ์ผœ ์ฐจ๋Ÿ‰์˜ ์•ˆ์ „์ฃผํ–‰์„ ๋•๋Š” ์‹œ์„ค๋กœ, ๋™๊ฒฐ์œตํ•ด, ์ œ์„ค์ œ์˜ ์‚ฌ์šฉ ๋“ฑ์œผ๋กœ ๋ฐœ์ƒํ•œ ๊ท ์—ด ์‚ฌ์ด๋กœ ์šฐ์ˆ˜, ๊ณต๊ธฐ, ์—ผํ™” ์ด์˜จ์ด ์นจํˆฌํ•˜๋Š” ๋“ฑ์˜ ์™ธ๋ถ€ํ™˜๊ฒฝ ๋ฟ ์•„๋‹ˆ๋ผ ์ฐจ๋Ÿ‰ํ•˜์ค‘ ๋“ฑ ๋ณตํ•ฉ์  ์›์ธ์œผ๋กœ ์ธํ•˜์—ฌ ์ฝ˜ํฌ๋ฆฌํŠธ ๋‚ด๊ตฌ์„ฑ์ด ์ €ํ•˜๋œ๋‹ค.

์ด๋Ÿฌํ•œ ๋„๋กœ ์ธก๊ตฌ์—์„œ๋Š” ๋‚ด๊ตฌ์„ฑ์˜ ์ €ํ•˜๋กœ ์ธํ•˜์—ฌ 2~3๋…„ ์ฃผ๊ธฐ์˜ ์žฆ์€ ๋ณด์ˆ˜๋ณด๊ฐ•์ด ์ด๋ฃจ์–ด์ง€๋ฉฐ, ์ด์— ๋Œ€๋น„ํ•˜์—ฌ ์ผ๋ฐ˜ ์ฝ˜ํฌ๋ฆฌํŠธ์— ๋ผํ…์Šค ์ˆ˜์ง€๋ฅผ ํ˜ผ์ž…ํ•œ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ(Latex Modified Concrete; ์ดํ•˜ LMC)๊ฐ€ ์—ฐ๊ตฌ๋˜๊ณ  ์žˆ๋‹ค. ๊ฒฝํ™” ํ›„์˜ LMC๋Š” ๋ผํ…์Šค ์ž…์ž์˜ ๋ถˆํˆฌ์ˆ˜์„ฑ ํ•„๋ฆ„๋ง‰์— ์˜ํ•ด ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํˆฌ์ˆ˜์„ฑ์„ ๊ฐ์†Œ์‹œ์ผœ ์ˆ˜๋ถ„ ๋ฐ ์—ผ๋ถ„์˜ ์นจํˆฌ๋ฅผ ๋ฐฉ์ง€ํ•˜์—ฌ ๋‚ด๊ตฌ์„ฑ์„ ํ–ฅ์ƒ์‹œํ‚ค๊ณ  ํœจ ๋ฐ ์ธ์žฅ๊ฐ•๋„๋ฅผ ์ฆ์ง„์‹œ์ผœ ๊ณต์šฉ ์—ฐ์ˆ˜๊ฐ€ ์ฆ๊ฐ€ํ•˜๋Š” ํŠน์„ฑ์„ ๊ฐ€์ง„๋‹ค(Ohama 1995). ๊ตญ๋‚ด์—์„œ๋Š” LMC๋ฅผ ์ด์šฉํ•œ ๋„๋กœํฌ์žฅ์ด ๋‹ค์ˆ˜ ์ด๋ฃจ์–ด์ง€๊ณ  ์žˆ์œผ๋ฉฐ ๋‚ด๊ตฌ์„ฑ ๊ฐœ์„  ๋“ฑ ๋งŽ์€ ์žฅ์ ์ด ์žˆ์œผ๋‚˜ ๋‹ค๋ฅธ ๊ณต๋ฒ•์— ๋น„ํ•ด ์ดˆ๊ธฐ ํˆฌ์ž๋น„์šฉ์ด ๋†’์•„์„œ ๊ฒฝ์ œ์„ฑ์˜ ๋ฌธ์ œ๊ฐ€ ์žˆ๋‹ค(Seoul Transportation Authority 2010).

์ด์— ๋ผํ…์Šค ์ด์™ธ์˜ ๋‹ค๋ฅธ ์ฒจ๊ฐ€๋ฌผ์„ ํ˜ผ์ž…ํ•˜์—ฌ ๋‚ด๊ตฌ์„ฑ๋Šฅ์€ ์œ ์ง€ํ•˜๋˜ ๊ฒฝ์ œ์„ฑ์„ ๊ฐœ์„ ํ•˜๊ณ ์ž ํ•˜๋Š” ์—ฐ๊ตฌ๊ฐ€ ์ตœ๊ทผ ์ง„ํ–‰๋˜๊ณ  ์žˆ๋‹ค. Choi et al.(2014)์€ ๋ผํ…์Šค์™€ ๊ด‘๋ฌผ์งˆ์ฒจ๊ฐ€์ œ๋ฅผ ํ˜ผ์ž…ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์— ๋Œ€ํ•ด ์‹คํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ , ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ผํ…์Šค๋ฅผ 8 % ์ด์ƒ ํ˜ผ์ž…ํ•˜๊ณ  ๊ด‘๋ฌผ์งˆ ์ฒจ๊ฐ€์ œ๋ฅผ ํ˜ผ์ž…ํ•  ๊ฒฝ์šฐ ๊ธฐ์กด LMC์™€ ๋™๋“ฑ ์ด์ƒ์˜ ๋‚ด๊ตฌ์„ฑ์„ ํ™•๋ณดํ•˜๋ฉฐ ์••์ถ•๊ฐ•๋„, ํœจ๊ฐ•๋„, ๋ถ€์ฐฉ๊ฐ•๋„๊ฐ€ ๊ตญ๋‚ด ๊ต๋ฉดํฌ์žฅ์ฝ˜ํฌ๋ฆฌํŠธ๊ฐ€ ์š”๊ตฌํ•˜๋Š” ์ˆ˜์ค€์„ ๋งŒ์กฑํ•˜๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. Park et al.(2012a)์€ ๋ผํ…์Šค์™€ ๋‚˜์ผ๋ก  ์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํœจ๊ฐ•๋„, ์ถฉ๊ฒฉ์ €ํ•ญ์„ฑ์„ ํ‰๊ฐ€ํ•˜์˜€๊ณ , ๋ผํ…์Šค ํ˜ผ์ž…๋ฅ ์ด ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ๋ผํ…์Šค ํ•„๋ฆ„์ด ํ˜•์„ฑ๋˜์–ด ์žฌ๋ฃŒ ๊ฐ„ ๋ถ€์ฐฉ๊ฐ•๋„๊ฐ€ ์ฆ๊ฐ€๋˜๊ธฐ ๋•Œ๋ฌธ์— ํœจ๊ฐ•๋„ ๋ฐ ์ถฉ๊ฒฉ์ €ํ•ญ์„ฑ์ด ํ–ฅ์ƒ๋จ์„ ์‹ค์ฆํ•˜์˜€๋‹ค. Hong et al.(2006)์€ ํ”Œ๋ผ์ด ์• ์‰ฌ๋ฅผ ํ˜ผ์ž…ํ•œ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ณต๊ธฐ๋Ÿ‰, ์••์ถ•๊ฐ•๋„, ํˆฌ์ˆ˜์ €ํ•ญ์„ฑ์„ ํ‰๊ฐ€ํ•˜์˜€๊ณ , ํ”Œ๋ผ์ด ์• ์‰ฌ์˜ ํ˜ผ์ž…๋ฅ ์ด ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ํ”Œ๋ผ์ด ์• ์‰ฌ๋กœ ์ธํ•œ ํฌ์กธ๋ž€ ๋ฐ˜์‘์˜ ์˜ํ–ฅ์œผ๋กœ ๊ธฐ์กด์˜ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์— ๋ณด๋‹ค ๊ณต๊ธฐ๋Ÿ‰ ๊ฐ์†Œ, ์••์ถ•๊ฐ•๋„ ๋ฐœํ˜„์ •๋„์˜ ๊ฐœ์„  ๋ฐ ํˆฌ์ˆ˜์ €ํ•ญ์„ฑ์ด ํ–ฅ์ƒ๋จ์„ ์‹ค์ฆํ•˜์˜€๋‹ค.

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ๋ผํ…์Šค ์ค‘๋Ÿ‰๋น„ 30 %์˜ ์ผ๋ฐ˜์ ์ธ ๋„๋กœ ์ธก๊ตฌ์šฉ LMC์˜ ๊ฒฝ์ œ์„ฑ์„ ๊ฐœ์„ ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์— ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ ํ˜ผ์ž… ํ›„ ์žฌ๋ฃŒ์˜ ์—ญํ•™์„ฑ๋Šฅ๊ณผ ๋‚ด๊ตฌ์„ฑ๋Šฅ ์‹คํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ์ฃผ์š” ์‹คํ—˜๋ณ€์ˆ˜๋Š” ๋ผํ…์Šค์˜ ์ค‘๋Ÿ‰๋น„์™€ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์˜ ๋ถ€ํ”ผ๋น„์ด๋ฉฐ, ์žฌ๋ฃŒ ์—ญํ•™์„ฑ๋Šฅ ์‹คํ—˜์œผ๋กœ ์••์ถ•๊ฐ•๋„, ํœจ๊ฐ•๋„, ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ  ๋‚ด๊ตฌ์„ฑ๋Šฅ ์‹คํ—˜์œผ๋กœ ์ˆ˜๋ฐ€์„ฑ๋Šฅ, ๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ ์‹คํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ๊ฐ ์‹คํ—˜์€ KS ๊ทœ๊ฒฉ ๋˜๋Š” ASTM ๊ทœ๊ฒฉ์„ ๋”ฐ๋ผ์„œ ์ˆ˜ํ–‰๋˜์—ˆ๊ณ  ์ด๋ฅผ ๋ฐ”ํƒ•์œผ๋กœ ๋ผํ…์Šค์™€ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋ฅ ์— ๋”ฐ๋ฅธ ์˜ํ–ฅ์„ ๋น„๊ต ๋ถ„์„ํ•˜์˜€๋‹ค.

2. ์‹คํ—˜๊ณ„ํš ๋ฐ ๋ฐฉ๋ฒ•

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ธฐ๊ณ„์  ํŠน์„ฑ์„ ๊ทœ๋ช…ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ์••์ถ•๊ฐ•๋„, ํœจ๊ฐ•๋„ ์‹คํ—˜, ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ , ๋‚ด๊ตฌ์„ฑ๋Šฅ์„ ๊ทœ๋ช…ํ•˜๊ธฐ ์œ„ํ•ด ์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜, ๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ ์‹คํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. 10 %, 15 % ์ค‘๋Ÿ‰๋น„์˜ ๋ผํ…์Šค ํ˜ผ์ž…๋ฅ ๊ณผ 0.2 %์™€ 0.3 % ๋ถ€ํ”ผ๋น„์˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋ฅ ์„ ์ฃผ์š” ๋ณ€์ˆ˜๋กœ ๊ฐ ๋ณ€์ˆ˜๋งˆ๋‹ค 3๊ฐœ ๋˜๋Š” 4๊ฐœ์˜ ์‹คํ—˜์ฒด๋ฅผ ์ œ์ž‘ํ•˜๊ณ  ์‹คํ—˜ํ•˜์˜€๋‹ค. ์‹คํ—˜๋ณ€์ˆ˜๋Š” ์ด 3์ข…์œผ๋กœ ๋ผํ…์Šค 10 %์™€ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  0.3 %๋ฅผ ํ•จ์œ ํ•œ ๋ณ€์ˆ˜ โ€˜L10-F0.3โ€™, ๋ผํ…์Šค 15 %์™€ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  0.2 %๋ฅผ ํ•จ์œ ํ•œ ๋ณ€์ˆ˜ โ€˜L15- F0.2โ€™, ๋ผํ…์Šค 15 %, ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  0.3 %๋ฅผ ํ•จ์œ ํ•œ ๋ณ€์ˆ˜ โ€˜L15-F0.3โ€™ ์ด๋‹ค.

2.1 ์‚ฌ์šฉ ์žฌ๋ฃŒ

๋ณธ ์žฌ๋ฃŒ ์‹คํ—˜์—์„œ ๊ตต์€ ๊ณจ์žฌ๋กœ๋Š” ์ตœ๋Œ€์น˜์ˆ˜ 20 mm, ๋น„์ค‘ 2.65์ธ ์‡„์„์„ ์‚ฌ์šฉํ•˜์˜€๊ณ , ์ž”๊ณจ์žฌ๋กœ๋Š” ๋น„์ค‘ 2.6์˜ ๊ฐ•๋ชจ๋ž˜๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ๋Œ€์šฉ๋Ÿ‰ ์ƒ์‚ฐ ์‹œ๊ณต ์‹œ ๊ฒฝ์ œ์„ฑ์„ ํ™•๋ณดํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๋ผํ…์Šค, ๋น„์ •์งˆ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ , ์ผ๋ฐ˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ ํ•จ๊ป˜ ์‚ฌ์šฉํ•˜์˜€๊ณ , ์ด๋ฅผ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์˜ ์žฌ๋ฃŒํŠน์„ฑ์€ Table 1๊ณผ Fig. 1์— ์ œ์‹œํ•˜์˜€๋‹ค.

Table 1 Properties of amorphous steel fibers and micro steel fibers

/Resources/kci/JKCI.2018.30.3.325/images/Table_CONCRETE_30_3_10_T1.jpg

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F1.jpg

Fig. 1

Geometric characteristics of amorphous steel fibers

๋ผํ…์Šค๋กœ๋Š” ๊ณ ํ˜•๋ถ„ ํ•จ๋Ÿ‰ 48.5 %์˜ ์œ ๋ฐฑ์ƒ‰ ์•ก์ฒด๋กœ ์ ์„ฑ 130, pH 9.7์ธ ๋ผํ…์Šค๋กœ ๊ตญ๋‚ด ๋„๋กœํฌ์žฅ์šฉ ์ƒ์‚ฐ ์‹œ๊ณต๋˜๊ณ  ์žˆ๋Š” ๊ตญ๋‚ด K ์‚ฌ์˜ ์Šคํ‹ธ๋ Œ-๋ถ€ํƒ€๋””์—” ๋ผํ…์Šค ํƒ€์ž…(Styrene-Butadiene Latex)์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

๋น„์ •์งˆ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋Š” ์„ฌ์œ ๋‘๊ป˜ 24 ยตm ๊ธธ์ด 15 mm, ํ˜•์ƒ๋น„ 86์ธ ๋‚ฉ์ž‘ํ•œ ์ŠคํŠธ๋ ˆ์ดํŠธ ํƒ€์ž…์˜ ๊ฐ•์„ฌ์œ ๋กœ์จ ๊ฐ• ์ด์™ธ์— ์ง€๋ฅด์ฝ”๋Š„, ํ‹ฐํƒ€๋Š„, ๋‹ˆ์ผˆ, ๊ตฌ๋ฆฌ ๋“ฑ์ด ํ˜ผํ•ฉ๋œ ๋ณตํ•ฉ๊ธˆ์†์žฌ๋ฃŒ์ด๋‹ค(Choi et al. 2015). ๋น„์ •์งˆ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋Š” ์ผ์ •ํ•œ ํ˜•ํƒœ์˜ ๊ฒฐ์ •๊ตฌ์กฐ๋ฅผ ๊ฐ–์ง€ ์•Š๋Š” ์žฌ๋ฃŒ๋กœ ์ผ๋ฐ˜์ ์ธ ๊ฐ•์„ฌ์œ ์— ๋น„ํ•ด 4~5๋ฐฐ์˜ ์ธ์žฅ๊ฐ•๋„, 1,000๋ฐฐ ์ด์ƒ์˜ ๋ถ€์‹ ์ €ํ•ญ์„ฑ ๋“ฑ์˜ ์šฐ์ˆ˜ํ•œ ์„ฑ๋Šฅ์„ ๊ฐ–๊ณ  ์žˆ๋‹ค.

๋น„์ •์งˆ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์™€ ํ•จ๊ป˜ ํ˜ผ์ž…๋˜๋Š” ์ผ๋ฐ˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋Š” ์„ฌ์œ ์ง๊ฒฝ 0.2 mm, ๊ธธ์ด 13 mm ํ˜•์ƒ๋น„ 65์ธ ์ŠคํŠธ๋ ˆ์ดํŠธ ํƒ€์ž…์˜ ๊ฐ•์„ฌ์œ ๋กœ์จ, ์ผ๋ฐ˜์ ์œผ๋กœ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ ๋˜๋Š” ์ดˆ๊ณ ์„ฑ๋Šฅ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ฐœ๋ฐœ์—์„œ ์‚ฌ์šฉ๋œ๋‹ค(Kang and Hong 2014; Lim and Hong 2016). Park and Kim(2015)์— ๋”ฐ๋ฅด๋ฉด ์ฝ˜ํฌ๋ฆฌํŠธ์— ๊ฐ•์„ฌ์œ ๋ฅผ ํˆฌ์ž…ํ•  ๊ฒฝ์šฐ ๊ฐ•์„ฌ์œ ๊ฐ€ ์šฐ์ˆ˜์˜ ์œ ์ž…๊ฒฝ๋กœ๊ฐ€ ๋˜์–ด ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ดํ™”๋ฅผ ์ด‰์ง„์‹œํ‚ค๋Š” ๊ฒฝํ–ฅ์ด ์žˆ์œผ๋ฏ€๋กœ, ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ด๋ฅผ ์ตœ์†Œํ™”ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ์ผ๋ฐ˜์ ์œผ๋กœ ์‚ฌ์šฉ๋˜๋Š” ์„ฌ์œ  ๊ธธ์ด 45 mm ๋Œ€์‹ ์— 13 mm, 15 mm์˜ ๋‹จ์„ฌ์œ ๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

2.2 ๋ฐฐํ•ฉ ์„ค๊ณ„

๋ณธ ์‹คํ—˜์˜ ๋ฐฐํ•ฉ ์„ค๊ณ„ ์‹œ ๋Œ€์šฉ๋Ÿ‰ ์ƒ์‚ฐ ๋ฐ ์‹œ๊ณต์„ ๊ณ ๋ คํ•˜์—ฌ ๋ฌผ-์‹œ๋ฉ˜ํŠธ ๋น„๋Š” 50 % ์ดํ•˜, ๊ตต์€ ๊ณจ์žฌ ์ตœ๋Œ€์น˜์ˆ˜๋Š” 25 mm ์ดํ•˜, ๊ณต๊ธฐ๋Ÿ‰์€ 5~7 %, ์Šฌ๋Ÿผํ”„๋Š” 150 ยฑ 10 mm์œผ๋กœ ์„ค์ •ํ•˜์˜€๋‹ค. ๋ฐฐํ•ฉ์„ค๊ณ„ ์‹œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํ’ˆ์งˆ์„ ํ™•๋ณดํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๋„๋กœ์„ค๊ณ„๊ธฐ์ค€(Ministry of Land, Transport and Maritime Affairs 2012), ๋„๋กœ๊ณต์‚ฌํ‘œ์ค€์‹œ๋ฐฉ์„œ(Ministry of Land, Infrastructure, and Transport 2015), ์ฝ˜ํฌ๋ฆฌํŠธ ํ‘œ์ค€์‹œ๋ฐฉ์„œ(Ministry of Land, Infrastructure, and Transport 2016), ์‹œ๋ฉ˜ํŠธ ์ฝ˜ํฌ๋ฆฌํŠธ ๋ฐฐํ•ฉ์„ค๊ณ„์ง€์นจ(Ministry of Land, Transport and Maritime Affairs 2009)์—์„œ ์ œ์‹œํ•˜๋Š” ํ’ˆ์งˆ๊ธฐ์ค€์— ์ถฉ์กฑํ•˜๋Š” ๋ฐฐํ•ฉ๊ธฐ์ค€์„ ๋”ฐ๋ผ ๋ฐฐํ•ฉ์„ค๊ณ„๋ฅผ ํ•˜์˜€๋‹ค. ๊ณต๊ธฐ๋Ÿ‰ ์‹œํ—˜์€ KS F 2421์˜ ๊ทœ์ •์— ์ค€ํ•˜์—ฌ ์‹ค์‹œํ•˜์˜€๊ณ  ์Šฌ๋Ÿผํ”„ ์‹œํ—˜์€ KS F 2402์˜ ๊ทœ์ •์— ๋”ฐ๋ผ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค.

์‹คํ—˜๋ณ€์ˆ˜๋ณ„ ๋ฐฐํ•ฉ๋น„๋Š” Table 2์— ์ œ์‹œํ•˜์˜€๋‹ค. ์‹คํ—˜๋ณ€์ˆ˜ L10-F0.3์˜ ๋ฐฐํ•ฉ๋น„๋Š” ๋ฌผ-์‹œ๋ฉ˜ํŠธ ๋น„ 47 %, ๊ณต๊ธฐ๋Ÿ‰ 5.3 %, ์Šฌ๋Ÿผํ”„ 160 mm์˜ ๊ฒฐ๊ณผ๋ฅผ ๊ฐ–๋Š” ๋ฐฐํ•ฉ๋น„๋กœ ๋น„์ •์งˆ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์™€ ์ผ๋ฐ˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋Š” ๊ฐ๊ฐ 11.7 kg์œผ๋กœ ์ด ๋ถ€ํ”ผ๋น„ 0.3 %, ๋ผํ…์Šค 49.4 kg์œผ๋กœ ์ด ์ค‘๋Ÿ‰๋น„ 10 %๋ฅผ ํฌํ•จํ•˜๊ณ  ์žˆ๋‹ค. ์‹คํ—˜๋ณ€์ˆ˜ L15-F0.2์˜ ๋ฐฐํ•ฉ๋น„๋Š” ๋ฌผ-์‹œ๋ฉ˜ํŠธ ๋น„ 47 %๋กœ ๊ณต๊ธฐ๋Ÿ‰ 6.0 %, ์Šฌ๋Ÿผํ”„ 150 mm์˜ ๊ฒฐ๊ณผ๋ฅผ ๊ฐ–๋Š” ๋ฐฐํ•ฉ๋น„๋กœ ๋น„์ •์งˆ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์™€ ์ผ๋ฐ˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ๊ฐ๊ฐ 7.8 kg์”ฉ ์ด ๋ถ€ํ”ผ๋น„ 0.2 %, ๋ผํ…์Šค 74.2 kg์œผ๋กœ ์ค‘๋Ÿ‰๋น„ 15 %๋ฅผ ํฌํ•จํ•˜๊ณ  ์žˆ๋‹ค. ์‹คํ—˜๋ณ€์ˆ˜ L15-F0.3์€ ๋ฌผ-์‹œ๋ฉ˜ํŠธ ๋น„ 45 %, ๊ณต๊ธฐ๋Ÿ‰ 6.2 %, ์Šฌ๋Ÿผํ”„ 165 mm๋ฅผ ๊ฐ–๋Š” ๋ฐฐํ•ฉ๋น„๋กœ ๋น„์ •์งˆ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์™€ ์ผ๋ฐ˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ ๊ฐ๊ฐ 11.7 kg์”ฉ ์ด ๋ถ€ํ”ผ๋น„ 0.3 %, ๋ผํ…์Šค 74.2 kg์œผ๋กœ ์ค‘๋Ÿ‰๋น„ 15 %๋ฅผ ํฌํ•จํ•˜๊ณ  ์žˆ๋‹ค. ๋ฐฐํ•ฉ์„ค๊ณ„ ์‹œ ์Šฌ๋Ÿผํ”„, ๊ณต๊ธฐ๋Ÿ‰์„ ๊ฐ€๊ธ‰์  ์ผ์น˜์‹œํ‚ค๊ธฐ ์œ„ํ•˜์—ฌ ๋ฌผ, ๊ณจ์žฌ, ์‹œ๋ฉ˜ํŠธ์˜ ๋น„์œจ์„ ๋ฐ˜๋ณต์‹คํ—˜์„ ํ†ตํ•ด ์กฐ์ •ํ•˜์˜€๋‹ค.

Table 2 Mix propotion of test specimens

/Resources/kci/JKCI.2018.30.3.325/images/Table_CONCRETE_30_3_10_T2.jpg

2.3 ์‹คํ—˜ ๋ฐฉ๋ฒ•

2.3.1 ์••์ถ•๊ฐ•๋„ ๋ฐ ํœจ๊ฐ•๋„ ์‹คํ—˜ ๋ฐฉ๋ฒ•

KS F 2403์— ๋”ฐ๋ผ ์••์ถ•๊ฐ•๋„์™€ ํœจ๊ฐ•๋„ ๊ณต์‹œ์ฒด๋ฅผ ์ œ์ž‘ ํ›„, ์••์ถ•๊ฐ•๋„ ์‹คํ—˜์€ KS F 2405์— ๋”ฐ๋ผ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ  ํœจ๊ฐ•๋„ ์‹คํ—˜์€ KS F 2408์˜ ๊ทœ์ •์— ๋”ฐ๋ผ์„œ ์‹ค์‹œํ•˜์˜€๋‹ค. ํœจ๊ฐ•๋„ ์‹คํ—˜์€ ์žฌ๋ฃŒ์˜ ์ตœ๋Œ€ ํœจ๊ฐ•๋„ ์ดํ›„ ์ž”๋ฅ˜๊ฐ•๋„ ๊ฐ์†Œ๊ตฌ๊ฐ„์˜ ๊ฑฐ๋™ํŠน์„ฑ์„ ํ™•์ธํ•˜๊ณ ์ž ์ตœ๋Œ€ํ•˜์ค‘์˜ 30 %๊นŒ์ง€ ์‹คํ—˜์ฒด๋ฅผ ๊ฐ€๋ ฅํ•˜์˜€๋‹ค. ์••์ถ•๊ฐ•๋„ ์‹คํ—˜์€ ํ•˜์ค‘์ œ์–ด๋กœ ์ˆ˜ํ–‰๋˜์—ˆ์œผ๋ฉฐ ๊ฐ€๋ ฅ์†๋„๋Š” 262.6 kN/min์ด๊ณ  ํœจ๊ฐ•๋„ ์‹คํ—˜์€ ๋ณ€์œ„์ œ์–ด๋กœ ์ˆ˜ํ–‰๋˜์—ˆ์œผ๋ฉฐ ๊ฐ€๋ ฅ์†๋„๋Š” 0.05 mm/min์ด๋‹ค. ์ด๋Š” KS ๊ทœ๊ฒฉ์—์„œ ์ œ์‹œํ•˜๋Š” ๊ฐ€๋ ฅ์กฐ๊ฑด์„ ๋งŒ์กฑํ•œ๋‹ค.

2.3.2 ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜ ๋ฐฉ๋ฒ•

๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜์€ ASTM C 1581-04(2004)์„ ๋”ฐ๋ผ ์ˆ˜ํ–‰๋˜์—ˆ๋‹ค. Fig. 2์™€ ๊ฐ™์ด ๊ฑฐํ‘ธ์ง‘์šฉ ์™ธ๋ถ€๋ง, ๊ฐ•์žฌ ๋‚ด๋ถ€๋ง, ๋ฐ”๋‹ฅํŒ์œผ๋กœ ๊ตฌ์„ฑ๋œ ๋งํ˜• ์ง€๊ทธ๋ฅผ ์ œ์ž‘ํ•˜๊ณ , ์ง€๊ทธ ๋‚ด๋ถ€๋ง ์•ˆ์ชฝ์— 2๊ฐœ์˜ ์ŠคํŠธ๋ ˆ์ธ๊ฒŒ์ด์ง€๋ฅผ ๋Œ€์นญ์ด ๋˜๋„๋ก ๋ถ€์ฐฉํ•˜์˜€๋‹ค. ์ฝ˜ํฌ๋ฆฌํŠธ๊ฐ€ ํƒ€์„ค๋  ๋‚ด๋ถ€๋ง๊ณผ ์™ธ๋ถ€๋ง ์‚ฌ์ด์˜ ๊ฐ•์žฌ๋ฉด์— ์œคํ™œ๋ฅ˜๋ฅผ ๋„ํฌํ•˜์—ฌ ์‰ฝ๊ฒŒ ํƒˆํ˜•๋  ์ˆ˜ ์žˆ๋„๋ก ํ•œ ํ›„, ํƒ€์„ค ๋ฐ ์–‘์ƒ ์‹œ ๋ฌผ์ด ์ƒˆ์–ด๋‚˜๊ฐ€์ง€ ์•Š๋„๋ก ์™ธ๋ถ€๋ง์˜ ๋ฐ”๊นฅ๋ฉด๊ณผ ๋‚ด๋ถ€๋ง์˜ ์•ˆ์ชฝ๋ฉด ๋ฐ‘์— ์‹ค๋ฆฌ์ฝ˜ ์‹ค๋ง์„ ํ•˜์˜€๋‹ค. ๋งํ˜• ์ง€๊ทธ์— ์ฝ˜ํฌ๋ฆฌํŠธ๋ฅผ 100ํšŒ ๋‹ค์ง์„ ํ•˜์—ฌ ํƒ€์„คํ•˜๊ณ  ๋ง์„ ๊ณ ์ •ํ•˜๊ณ  ์žˆ๋Š” ๋ณผํŠธ๋ฅผ ํ‘ผ ๋’ค ์ŠคํŠธ๋ ˆ์ธ ๊ฒŒ์ด์ง€๋ฅผ ๋ฐ์ดํ„ฐ๋กœ๊ฑฐ์™€ ์—ฐ๊ฒฐ์‹œํ‚ค๊ณ  ์™ธ๊ธฐ์— ๋…ธ์ถœ๋œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์œ—๋ฉด์€ ๋น„๋‹๋ฉด์œผ๋กœ ๋ฎ์–ด ํ‘œ๋ฉด๊ฑด์กฐ๊ฐ€ ๋ฐœ์ƒํ•˜์ง€ ์•Š๋„๋ก ํ•˜์˜€๋‹ค. ์˜จยท์Šต๋„์‹ค์—์„œ 48์‹œ๊ฐ„ ์–‘์ƒ ํ›„ ์™ธ๋ถ€๋ง์„ ์ œ๊ฑฐํ•˜๊ณ  ์›์ฃผ๋ฐฉํ–ฅ๋งŒ์˜ ๊ฑด์กฐ์ˆ˜์ถ• ์‹œํ—˜์„ ํ•˜๊ธฐ ์œ„ํ•ด ์ฝ˜ํฌ๋ฆฌํŠธ ๋ง ์œ—๋ฉด์„ ์‹ค๋ฆฌ์ฝ˜์œผ๋กœ ๋งˆ๊ฐ์ฒ˜๋ฆฌ๋ฅผ ํ•˜์˜€๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F2.jpg

Fig. 2

Setup for shrinkage test

์‹คํ—˜๊ธฐ๊ฐ„ ๋‚ด์— ์˜จ๋„๋Š” 11 ยฑ 2 ยฐC, ์Šต๋„๋Š” 55 ยฑ 10 %๋ฅผ ์œ ์ง€ํ•˜์˜€์œผ๋ฉฐ ์™ธ๋ถ€๋ง ํƒˆํ˜•์„ ๊ธฐ์ ์œผ๋กœ 15๋ถ„ ๊ฐ„๊ฒฉ์œผ๋กœ ๋ณ€ํ˜•๋ฅ  ์ธก์ •์„ ์‹œ์ž‘ํ•˜์˜€๋‹ค. ์‹คํ—˜์ฒด์˜ ํ‘œ๋ฉด๊ด€์ฐฐ์—์„œ ๊ท ์—ด์ด ๋ฐœ์ƒํ•œ ์ดํ›„๋ถ€ํ„ฐ ํ•˜๋ฃจ 1๋ฒˆ ๊ท ์—ด ์ธก์ • ์žฅ์น˜(FASTFCV-50)๋กœ ๊ท ์—ด์„ ์ธก์ •ํ•˜์˜€๋‹ค. ๊ด€ํ†ต๊ท ์—ด์˜ ๊ฒฝ์šฐ ์œ„, ์•„๋ž˜ ๋‘ ๊ณณ์„ ์ธก์ •ํ•˜์—ฌ ํ‰๊ท ์„ ๊ท ์—ดํญ์œผ๋กœ ๊ฒฐ์ •ํ•˜์˜€๊ณ  ๋ฏธ์„ธ๊ท ์—ด์˜ ๊ฒฝ์šฐ ๊ท ์—ด์‹œ์ž‘๋ถ€๋ถ„์„ ๊ท ์—ดํญ์œผ๋กœ ์ธก์ •ํ•˜์˜€๋‹ค.

2.3.3 ์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜ ๋ฐฉ๋ฒ•

์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜์€ KS F 2609์— ๋”ฐ๋ผ์„œ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ  ์‹คํ—˜์…‹์—…์€ Fig. 3์— ์ œ์‹œํ•˜์˜€๋‹ค. ์‹คํ—˜์ฒด๋Š” KS F 2609์„ ๋”ฐ๋ผ์„œ 50 mm ร— 100 mm ร— 30 mm(๊ฐ€๋กœ ร— ์„ธ๋กœ ร— ๋†’์ด)์˜ ํฌ๊ธฐ๋กœ ์ œ์ž‘ํ•˜์˜€๋‹ค. ์‹คํ—˜์ฒด๋ฅผ ์˜จ๋„ 20 ยฑ 2 ยฐC, ์ƒ๋Œ€์Šต๋„ 65 ยฑ 5 %์—์„œ ํ•ญ๋Ÿ‰์ด ๋  ๋•Œ๊นŒ์ง€ ๊ฑด์กฐ์‹œํ‚จ ํ›„, ์‹คํ—˜์ฒด ์ธก๋ฉด์„ ์—ํญ์‹œ๋กœ ๋ฐฉ์ˆ˜์ฒ˜๋ฆฌํ•˜์—ฌ ์•ฝ 20 ยฐC์˜ ๋ฌผ์— 5 mm์˜ ๊นŠ์ด๋กœ ๋‹ด๊ทธ๊ณ  10๋ถ„, 30๋ถ„, 1์‹œ๊ฐ„, 6์‹œ๊ฐ„, 24์‹œ๊ฐ„ ๊ฐ„๊ฒฉ์œผ๋กœ ์‹คํ—˜์ฒด์˜ ์งˆ๋Ÿ‰์„ ์ธก์ •ํ•˜์˜€๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F3.jpg

Fig. 3

Setup for water-tightness test

์‹คํ—˜์ฒด์˜ ๋ฌผ ํก์ˆ˜๊ณ„์ˆ˜ /Resources/kci/JKCI.2018.30.3.325/images/PIC3240.gif๋Š” KS F 2609์— ์ œ์‹œ๋œ ๋‹ค์Œ์˜ ์‹ (1)์„ ์ด์šฉํ•˜์—ฌ ๊ณ„์‚ฐํ•˜์˜€๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/PIC3251.gif                                                                        (1)

์—ฌ๊ธฐ์„œ /Resources/kci/JKCI.2018.30.3.325/images/PIC3252.gif์€ ๋ฉด์ ๋‹น ๋ฌผ ํก์ˆ˜๋Ÿ‰(kg/m2), /Resources/kci/JKCI.2018.30.3.325/images/PIC3262.gif๋Š” ๋ฌผ ํก์ˆ˜ ๊ณ„์ˆ˜(kg/m2h0.5), /Resources/kci/JKCI.2018.30.3.325/images/PIC3263.gif๋Š” ์‹œ๊ฐ„(h)์ด๋‹ค.

2.3.4 ๋™๊ฒฐ์œตํ•ด ์‹คํ—˜ ๋ฐฉ๋ฒ•

๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ ์‹คํ—˜์€ KS F 2456์˜ ์ˆ˜์ค‘ ๊ธ‰์† ๋™๊ฒฐ ์œตํ•ด ์‹œํ—˜ ๋ฐฉ๋ฒ•(A Type)์„ ๋”ฐ๋ผ์„œ ๊ณต์ธ์‹œํ—˜๊ธฐ๊ด€์—์„œ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ๊ฐ ๋™๊ฒฐ์œตํ•ด ์‚ฌ์ดํด์€ ์‹คํ—˜์ฒด ์ค‘์‹ฌ์˜ ์˜จ๋„๋ฅผ ๊ธฐ์ค€์œผ๋กœ ๋™๊ฒฐ ์‹œ โ€“18 ยฐC, ์œตํ•ด ์‹œ 4 ยฐC๋กœ ์ƒ์Šน์‹œํ‚ค๋Š” ๊ณผ์ •์ด๋ฉฐ, ์†Œ์š”์‹œ๊ฐ„์€ 4์‹œ๊ฐ„์ด๋‹ค. ๊ฐ ์‹คํ—˜์ฒด๋Š” 300์‚ฌ์ดํด์˜ ๋ฐ˜๋ณต ํ›„ ์‹คํ—˜์„ ์ข…๋ฃŒํ•˜์˜€๋‹ค. ์‹คํ—˜ ๊ฒฐ๊ณผ๋ฅผ ๋ฐ”ํƒ•์œผ๋กœ KS F 2456์— ์ œ์‹œ๋œ ์•„๋ž˜์˜ ์‹์— ๋”ฐ๋ผ ์ƒ๋Œ€ ๋™ ํƒ„์„ฑ๊ณ„์ˆ˜ /Resources/kci/JKCI.2018.30.3.325/images/PIC3274.gif๋ฅผ ์‚ฐ์ •ํ•˜์˜€๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/PIC3275.gif                                                                   (2)

์—ฌ๊ธฐ์„œ. /Resources/kci/JKCI.2018.30.3.325/images/PIC3286.gif๋Š” /Resources/kci/JKCI.2018.30.3.325/images/PIC3287.gif๋ฒˆ์งธ ๋™๊ฒฐ์œตํ•ด ์‚ฌ์ดํด ํ›„์˜ ์ƒ๋Œ€ ๋™ ํƒ„์„ฑ ๊ณ„์ˆ˜(%), /Resources/kci/JKCI.2018.30.3.325/images/PIC3288.gif๋Š” 0๋ฒˆ์งธ ๋™๊ฒฐ์œตํ•ด ์‚ฌ์ดํด์—์„œ์˜ ๋ณ€ํ˜• ์ง„๋™์˜ 1์ฐจ ๊ณต๋ช… ์ง„๋™์ˆ˜(Hz), /Resources/kci/JKCI.2018.30.3.325/images/PIC3298.gif๋Š” /Resources/kci/JKCI.2018.30.3.325/images/PIC3299.gif๋ฒˆ์งธ ๋™๊ฒฐ์œตํ•ด ์‚ฌ์ดํด ํ›„์˜ ๋ณ€ํ˜• ์ง„๋™์˜ 1์ฐจ ๊ณต๋ช… ์ง„๋™์ˆ˜(Hz)์ด๋‹ค.

3. ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-LMC์˜ ์—ญํ•™ ํŠน์„ฑ

3.1 ์••์ถ•๊ฐ•๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

์••์ถ•๊ฐ•๋„ ์‹คํ—˜์€ ์žฌ๋ น์ผ์— ๋”ฐ๋ฅธ ์••์ถ•๊ฐ•๋„ ๋ฐœํ˜„์„ ํ™•์ธํ•˜๊ธฐ ์œ„ํ•˜์—ฌ 4์ผ, 7์ผ, 14์ผ, 28์ผ ์ด 4๋ฒˆ์— ๊ฑธ์ณ ์ˆ˜ํ–‰๋˜์—ˆ๊ณ , ๋งค ์‹คํ—˜๋งˆ๋‹ค 3๊ฐœ์˜ ๊ณต์‹œ์ฒด๋ฅผ ์‹คํ—˜ํ•˜์—ฌ ํ‰๊ท ๊ฐ’์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

๋ฐฐํ•ฉ์„ค๊ณ„ ์‹œ L10-F0.3๊ณผ L15-F0.3์˜ ์žฌ๋ น 28์ผ ๋ชฉํ‘œ์••์ถ•๊ฐ•๋„๋Š” 21 MPa, L15-F0.2๋Š” 18 MPa์ด๊ณ , ์žฌ๋ น 28์ผ์˜ ์••์ถ•๊ฐ•๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ L10-F0.3์€ 22.64 MPa, L15-F0.2๋Š” 17.65 MPa, L15-F0.3์€ 22.98 MPa์ด๋‹ค. ์‹คํ—˜๋ณ€์ˆ˜์˜ ์žฌ๋ น๋ณ„ ์‹คํ—˜์ฒด์˜ ์••์ถ•๊ฐ•๋„ ์ตœ๋Œ“๊ฐ’, ์ตœ์†Ÿ๊ฐ’, ํ‰๊ท ๊ฐ’ ๊ฐ•๋„๋ฐœํ˜„์ถ”์ด๋ฅผ Fig. 4์— ์ œ์‹œํ•˜์˜€๋‹ค. Fig. 5์—์„œ L10-F0.3๋Š” ์žฌ๋ น 7์ผ์— ์žฌ๋ น 28์ผ ๊ฐ•๋„ ๋Œ€๋น„ 76 %์˜ ๊ฐ•๋„๊ฐ€ ๋ฐœํ˜„๋˜๊ณ  L15-F0.3์€ ์žฌ๋ น 7์ผ์— 73 %, L15-F0.3์€ ์žฌ๋ น 7์ผ์— 91 %์˜ ๊ฐ•๋„๊ฐ€ ๋ฐœํ˜„๋œ๋‹ค. Kim et al.(2001)์€ ๋ผํ…์Šค 15 % ํ˜ผ์ž… ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ์žฌ๋ น 7์ผ์— 77 %์˜ ๊ฐ•๋„๊ฐ€ ๋ฐœํ˜„๋˜๋Š” ๊ฒƒ์œผ๋กœ ๋ณด๊ณ ํ•˜๊ณ  ์žˆ๋‹ค. Kim et al.(2001)์˜ ๋ผํ…์Šค 15 % ํ˜ผ์ž… ์ฝ˜ํฌ๋ฆฌํŠธ์— ๋Œ€ํ•œ ์‹คํ—˜ ๊ฒฐ๊ณผ์™€ ๋น„๊ตํ•  ๊ฒฝ์šฐ, L15-F0.2๋Š” ์žฌ๋ น 7์ผ์—์„œ์˜ ๊ฐ•๋„๋ฐœํ˜„ ์ •๋„๊ฐ€ 73 %, L10-F0.3์€ 76 %๋กœ ํฐ ์ฐจ์ด๊ฐ€ ์—†์œผ๋ฉฐ L15-F0.3์€ 91 %๋กœ ๊ฐ•๋„๋ฐœํ˜„ ์ •๋„๊ฐ€ ๋น ๋ฅธ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๊ฐ€ ์ผ์ •๋Ÿ‰ ์ด์ƒ ํ•จ์ž…์ด ๋˜๋ฉด ์กฐ๊ธฐ๊ฐ•๋„ ๋ฐœํ˜„์˜ ํšจ๊ณผ๊ฐ€ ์žˆ๋Š” ๊ฒƒ์€ Choi et al.(2015)์—์„œ๋„ ๋ณด๊ณ ๋œ ๋ฐ” ์žˆ๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F4.jpg

Fig. 4

Compression strengths by age

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F5.jpg

Fig. 5

Normalized compression strength at 7th day

3.2 ํœจ๊ฐ•๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

ํœจ๊ฐ•๋„ ์‹คํ—˜์ฒด๋Š” ๊ฐ ์‹คํ—˜๋ณ€์ˆ˜ ๋งˆ๋‹ค 3๊ฐœ์”ฉ ์ œ์ž‘ ๋ฐ ๊ฐ€๋ ฅ ํ•˜์˜€์œผ๋ฉฐ, L10-F0.3, L15-F0.2, L15-F0.3์˜ ํœจ๊ฐ•๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ ์ค‘ ๋Œ€ํ‘œ์ ์ธ ์‹คํ—˜ ๊ฒฐ๊ณผ๊ฐ€ Fig. 6์— ์ œ์‹œ๋˜์–ด์žˆ๋‹ค. L10-F0.3, L15- F0.2, L15-F0.3์˜ ํœจ๊ฐ•๋„๋Š” ๊ฐ๊ฐ 3.18 MPa, 4.13 MPa, 3.18 MPa์ด๋ฏ€๋กœ L15-F0.3์ด ์•ฝ 30 % ๋” ํฌ๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F6.jpg

Fig. 6

Flexural behavior of variables

L10-F0.3, L15-F0.2, L15-F0.3์˜ ์ตœ๋Œ€๊ฐ•๋„ ์งํ›„ ์ž”๋ฅ˜๊ฐ•๋„๋ฅผ Fig. 7์— ์ œ์‹œํ•˜์˜€๋‹ค. ๊ฐ ์‹คํ—˜์ฒด์—์„œ ์ตœ๋Œ€๊ฐ•๋„ ์งํ›„๋ถ€ํ„ฐ ์ฒ˜์ง์ด 2 mm๊นŒ์ง€์˜ ํ‰๊ท  ์ž”๋ฅ˜๊ฐ•๋„๋Š” L10-F0.3์˜ ๊ฒฝ์šฐ ์ตœ๋Œ€๊ฐ•๋„ ๋Œ€๋น„ 50.6 %, L15-F0.2์˜ ๊ฒฝ์šฐ 51.7 %, L15-F0.3์˜ ๊ฒฝ์šฐ 52.0 %๋กœ ํฐ ์ฐจ์ด๋Š” ์—†์œผ๋‚˜ ์ผ๋ฐ˜ ์ฝ˜ํฌ๋ฆฌํŠธ ๋Œ€๋น„ ๋งค์šฐ ์šฐ์ˆ˜ํ•˜๋‹ค. ์ด๋Š” ํŒŒ๊ดด ์‹œ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๊ฐ€ ๋ฝ‘ํžˆ๋ฉด์„œ ์—๋„ˆ์ง€๋ฅผ ์†Œ์‚ฐํ•˜๋Š” ๋ฉ”์ปค๋‹ˆ์ฆ˜์ด ๋ฐœ์ƒํ•˜๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค(Ku et al. 2014). Choi(2010)์— ๋”ฐ๋ฅด๋ฉด ์‚ฌ์šฉ๋œ ์ผ๋ฐ˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋Š” ์ตœ๋Œ€ ๊ฐ•๋„ ์ดํ›„ ๊ฐœ๋ณ„ ์„ฌ์œ ๊ฐ€ ๋ฝ‘ํžˆ๋ฉด์„œ ์—๋„ˆ์ง€๋ฅผ ์†Œ์‚ฐํ•˜๋Š” ๋ฐ˜๋ฉด, ๋น„์ •์งˆ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์™€์˜ ๊ฐœ๋ณ„ ์„ฌ์œ  ๊ฐ„ ๋ถ€์ฐฉ๋ ฅ์ด ์šฐ์ˆ˜ํ•˜์—ฌ ์ตœ๋Œ€๊ฐ•๋„ ์ดํ›„ ์„ฌ์œ ๊ฐ€ ํŒŒ๋‹จ๋˜๋ฏ€๋กœ ์ผ๋ฐ˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๊ฐ€ ์ž”๋ฅ˜๊ฐ•๋„ ๋ฐœํ˜„์— ํฐ ์˜ํ–ฅ์„ ๋ผ์นœ ๊ฒƒ์œผ๋กœ ๋ถ„์„๋œ๋‹ค. ๋˜ํ•œ ์†Œ๋Ÿ‰์˜ ๊ฐ•์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•˜์˜€์Œ์—๋„ ์ˆ˜ํ™”๋ฐ˜์‘ ์‹œ ํ˜•์„ฑ๋œ ๋ผํ…์Šค ํ•„๋ฆ„๋ง‰์ด ๊ณจ์žฌ์™€ ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ๋ฅผ ๊ฒฐ์†ํ•˜์—ฌ ์ฒœ์ด์˜์—ญ ๊ฐœ์„ ์— ๊ธฐ์—ฌํ•˜๊ธฐ ๋•Œ๋ฌธ์— ์•ฝ 50 %์˜ ์ž”๋ฅ˜๊ฐ•๋„๊ฐ€ ํ™•๋ณด๋˜๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F7.jpg

Fig. 7

Residual strengths of variables

์‹คํ—˜๋ณ€์ˆ˜๋ณ„ ์••์ถ•๊ฐ•๋„๊ฐ€ ์ฐจ์ด๊ฐ€ ์žˆ์œผ๋ฏ€๋กœ ์ด๋ฅผ ๊ณ ๋ คํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ํœจ ์ธ์žฅ๊ฐ•๋„ /Resources/kci/JKCI.2018.30.3.325/images/PIC32AA.gif์‹์œผ๋กœ ๊ตฌํ•œ ํœจ๊ฐ•๋„์™€ ์‹คํ—˜ ๊ฐ•๋„๋ฅผ ๊ฐ๊ฐ ๋น„๊ตํ•˜์˜€๋‹ค. Fig. 8์„ ๋ณด๋ฉด, L10-F0.3์˜ ๊ฒฝ์šฐ 3๊ฐœ์˜ ์‹คํ—˜์ฒด ํ‰๊ท  /Resources/kci/JKCI.2018.30.3.325/images/PIC32AB.gif์€ 3.37 MPa์ด๊ณ  ๊ณ„์‚ฐ๊ฐ•๋„ /Resources/kci/JKCI.2018.30.3.325/images/PIC32AC.gif 2.85 MPa ๋Œ€๋น„ ์•ฝ 18 % ์ฆ๊ฐ€ํ•˜์˜€๋‹ค. L15-F0.2์˜ ๊ฒฝ์šฐ ํœจ๊ฐ•๋„ ์‹คํ—˜๊ฐ’ /Resources/kci/JKCI.2018.30.3.325/images/PIC32BD.gif์€ 3๊ฐœ์˜ ์‹คํ—˜์ฒด ํ‰๊ท ๊ฐ’์ด 2.95 MPa์ด๊ณ  ๊ณ„์‚ฐ๊ฐ•๋„ /Resources/kci/JKCI.2018.30.3.325/images/PIC32BE.gif 2.52 MPa ๋Œ€๋น„ ์•ฝ 17 % ์ฆ๊ฐ€ํ•˜์˜€๋‹ค. L15-F0.3์˜ ๊ฒฝ์šฐ 3๊ฐœ์˜ ์‹คํ—˜์ฒด ํ‰๊ท  /Resources/kci/JKCI.2018.30.3.325/images/PIC32BF.gif์€ 3.86 MPa์ด๊ณ  ๊ณ„์‚ฐ๊ฐ•๋„ /Resources/kci/JKCI.2018.30.3.325/images/PIC32CF.gif 2.87 MPa ๋Œ€๋น„ ์•ฝ 34 % ์ฆ๊ฐ€ํ•˜์˜€๋‹ค. ๋”ฐ๋ผ์„œ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋ฅ ์ด ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ ํœจ๊ฐ•๋„๊ฐ€ ์ฆ๊ฐ€ํ•˜๊ณ , ๋™์ผํ•œ ์–‘์˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž… ์‹œ ๋ผํ…์Šค์˜ ํ˜ผ์ž…๋ฅ ์˜ ๋ณ€ํ™”์— ๋”ฐ๋ฅธ ํœจ๊ฐ•๋„ ์ฆ์ง„ํšจ๊ณผ๋Š” ๋ฏธ๋ฏธํ•œ ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค. ๊ทธ ์ด์œ ๋Š” ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๊ฐ€ ์žฌ๋ฃŒ ๋‚ด๋ถ€์—์„œ ์ธ์žฅ๋ ฅ ์ฆ๊ฐ€์— ๊ธฐ์—ฌํ•˜๊ณ  ์ธ๋ฐœ ์‹œ ์ƒ๊ธฐ๋Š” ๋งˆ์ฐฐ๋ ฅ์œผ๋กœ ๋ฐœ์ƒ๋˜๋Š” ์—๋„ˆ์ง€๊ฐ€ ํœจ๊ฐ•๋„ ์ฆ์ง„์— ์˜ํ–ฅ์„ ์ฃผ๊ธฐ ๋•Œ๋ฌธ์ธ ๊ฒƒ์œผ๋กœ ๋ถ„์„๋œ๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F8.jpg

Fig. 8

Comparison between flexural strengths

3.3 ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜์€ L15-F0.3์— ๋Œ€ํ•ด ์‹คํ—˜์ฒด 3๊ฐœ๋ฅผ ์ œ์ž‘ํ•˜์—ฌ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ  ์žฌ๋ น 38์ผ์— ์‹คํ—˜์„ ์ข…๋ฃŒํ•˜์˜€๋‹ค. 1๋ฒˆ ์‹คํ—˜์ฒด๋Š” 2๊ฐœ์˜ ๊ด€ํ†ต๊ท ์—ด์ด ๊ด€์ธก๋˜์—ˆ๊ณ  2๋ฒˆ ์‹คํ—˜์ฒด์—์„œ๋Š” 2๊ฐœ์˜ ์ƒ๋ถ€๊ท ์—ด๊ณผ 1๊ฐœ์˜ ๊ด€ํ†ต๊ท ์—ด, 3๋ฒˆ ์‹คํ—˜์ฒด์—์„œ๋Š” 2๊ฐœ์˜ ์ƒ๋ถ€๊ท ์—ด์ด ๊ด€์ธก๋˜์—ˆ๋‹ค. 1๋ฒˆ ์‹คํ—˜์ฒด๋Š” ์žฌ๋ น 18์ผ์— ์œก์•ˆ์œผ๋กœ ๊ท ์—ด์ด ๊ด€์ธก๋˜์—ˆ๊ณ , 2๋ฒˆ๊ณผ 3๋ฒˆ ์‹คํ—˜์ฒด๋Š” 1๋ฒˆ ์‹คํ—˜์ฒด ๋ณด๋‹ค ํ•˜๋ฃจ ๋Šฆ์€ 19์ผ์— ๊ท ์—ด์ด ๊ด€์ธก๋˜์—ˆ๋‹ค. 2๋ฒˆ ์‹คํ—˜์ฒด์—์„œ๋Š” ์ด 3๊ฐœ์˜ ๊ท ์—ด์ด ๊ด€์ธก๋˜์—ˆ๋Š”๋ฐ ๊ทธ ์ค‘ ์™ผ์ชฝ ํ•˜๋ถ€์˜ ๊ท ์—ด์€ ์žฌ๋ น 21์ผ๊ฒฝ์— ๋ฐœ์ƒํ•˜์˜€๋‹ค. Fig. 9์— ์‹คํ—˜์ฒด๋ณ„ ๊ท ์—ด๋ฐœ์ƒ ์œ„์น˜์™€ ๊ฐ ๊ท ์—ด์˜ ์ตœ๋Œ€ ๊ท ์—ดํญ ๋ฐ ๊ท ์—ด์‚ฌ์ง„์„ ์ œ์‹œํ•˜์˜€๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F9.jpg

Fig. 9

Crack development in ring test specimens

Fig. 10์—๋Š” L15-F0.3์˜ ๊ท ์—ดํญ์ด ์ œ์‹œ๋˜์–ด ์žˆ๋‹ค. ์œก์•ˆ์œผ๋กœ ๊ท ์—ด์ด ๊ด€์ธก๋˜๊ธฐ ์‹œ์ž‘ํ•œ ์žฌ๋ น 18์ผ๋ถ€ํ„ฐ ๊ท ์—ดํญ ์ธก์ •์„ ์‹œ์ž‘ํ•˜์˜€๋‹ค. ํ‰๊ท  ์ตœ๋Œ€ ๊ท ์—ดํญ์€ ์žฌ๋ น 38์ผ์˜ 0.19 mm์ด๊ณ  ์žฌ๋ น์— ๋”ฐ๋ฅธ ๊ท ์—ดํญ์€ ๊ท ์—ดํญ ์ธก์ •์‹œ์  ์ดํ›„ ๋ฏธ์„ธํ•˜๊ฒŒ ์ฆ๊ฐ€ํ•˜๋Š” ์–‘์ƒ์„ ๋ณด์ธ๋‹ค. ์ด๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ ๊ตฌ์กฐ๋ฌผ์˜ ๊ท ์—ดํญ์— ๋Œ€ํ•œ ๊ธฐ์ค€์ธ ACI 224R-01(2001)๋กœ ๋ช…์‹œํ•˜๊ณ  ์žˆ๋Š” ์Šต๋„๊ฐ€ ๋†’์€ ํ™˜๊ฒฝ์— ๋…ธ์ถœ๋œ ๊ตฌ์กฐ๋ฌผ์˜ ํ—ˆ์šฉ๊ท ์—ดํญ ๊ธฐ์ค€์ธ 0.3 mm๋ฅผ ๋งŒ์กฑํ•˜๊ณ , ์ œ๋น™ํ™”ํ•™์ œ, ์—ผ, ์†Œ๊ธˆ๋ฌผ, ๋ฐ”๋‹ท๋ฌผ์— ๋…ธ์ถœ๋œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํ—ˆ์šฉ๊ท ์—ดํญ์ธ 0.18 mm๋ฅผ ์•ฝ๊ฐ„ ์ดˆ๊ณผํ•œ๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F10.jpg

Fig. 10

Crack width of L15-F0.3

Choi et al.(2015)์˜ ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜ ๊ฒฐ๊ณผ์— ๋”ฐ๋ฅด๋ฉด ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๋ฅผ 0.4 % ๋ถ€ํ”ผ๋น„๋กœ ํ˜ผ์ž…ํ•œ ๊ฐ•์„ฌ์œ  ๋ณด๊ฐ• ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ตœ๋Œ€ ๊ท ์—ดํญ์€ 0.14 mm์ด๋‹ค. ์‹คํ—˜์— ์‚ฌ์šฉ๋œ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์˜ ์ข…๋ฅ˜์™€ ํˆฌ์ž…๋Ÿ‰์ด ์ƒ์ดํ•˜๋ฏ€๋กœ ์ด๋ฅผ ๊ณ ๋ คํ•˜์—ฌ L15-F0.3๊ณผ ๋น„๊ตํ–ˆ์„ ๋•Œ ๊ท ์—ด์ œ์–ด์„ฑ๋Šฅ์ด ์œ ์‚ฌํ•˜๋‹ค๊ณ  ๋ถ„์„๋œ๋‹ค.

๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ๋ณ€ํ˜•๋ฅ  ์ธก์ •๊ฒฐ๊ณผ์™€ ์ธก์ •ํ•œ ๊ท ์—ด๋ฐœ์ƒ์‹œ์ ์„ Fig. 11์— ์ œ์‹œํ•˜์˜€๋‹ค. ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ฑด์กฐ์ˆ˜์ถ•์— ์˜ํ•ด ๊ฐ•์žฌ์˜ ์••์ถ•๋ณ€ํ˜•๋ฅ ์ด ์ฆ๊ฐ€ํ•˜๋‹ค๊ฐ€ ๊ท ์—ด๋ฐœ์ƒ์œผ๋กœ ์ธํ•˜์—ฌ ๋ณ€ํ˜•๋ฅ ์ด ๊ธ‰๊ฒฉํžˆ ๊ฐ์†Œํ•˜๋Š” ์‹œ์ ์„ ๊ท ์—ด๋ฐœ์ƒ์‹œ์ ์œผ๋กœ ํ‰๊ฐ€ํ•˜์˜€๋‹ค(Shah and Weiss 2006). L15-F0.3์€ ์ธก์ • ์‹œ์ž‘ ํ›„ 10์ผ์งธ์— ๊ท ์—ด์ด ๋ฐœ์ƒํ•˜๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๊ณ  ์ด๋Š” ์‹คํ—˜์ฒด๋ฅผ ์œก์•ˆ์œผ๋กœ ํ™•์ธํ•œ ์‹œ์ ๊ณผ ์ฐจ์ด๊ฐ€ ์žˆ๋‹ค. ๊ท ์—ด๋ฐœ์ƒ ์ดํ›„ ์žฌ๋ น 10~12์ผ ๊ฐ„ ๋น„๊ต์  ๊ธ‰๊ฒฉํ•œ ๋ณ€ํ˜•๋ฅ ์˜ ๋ณ€ํ™”๊ฐ€ ์žˆ์—ˆ๊ณ  ์žฌ๋ น 25์ผ ์ดํ›„๋ถ€ํ„ฐ๋Š” ํฐ ํญ์œผ๋กœ ๋ณ€ํ˜•๋ฅ ์ด ๊ฐ์†Œํ•˜์˜€๋‹ค.

/Resources/kci/JKCI.2018.30.3.325/images/Figure_CONCRETE_30_3_10_F11.jpg

Fig. 11

Strain profile of L15-F0.3

4. ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-LMC์˜ ๋‚ด๊ตฌ์„ฑ๋Šฅ

4.1 ์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜์ฒด๋Š” ๋ณ€์ˆ˜๋ณ„๋กœ 4๊ฐœ์”ฉ ์ œ์ž‘ํ•˜์˜€๋‹ค. Table 3์˜ ์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜๊ฒฐ๊ณผ์— ๋”ฐ๋ฅด๋ฉด, L15-F0.2์˜ ํ‰๊ท  ๋ฌผ ํก์ˆ˜๊ณ„์ˆ˜ /Resources/kci/JKCI.2018.30.3.325/images/PIC32D0.gif๋Š” 0.165 kg/m2h0.5์ด๊ณ , L15-F0.3์˜ ํ‰๊ท  ๋ฌผ ํก์ˆ˜๊ณ„์ˆ˜ /Resources/kci/JKCI.2018.30.3.325/images/PIC32D1.gif๋Š” 0.133 kg/m2h0.5์ด๋‹ค. ์„ ํ–‰์—ฐ๊ตฌ์™€ KS F 4042 ๋“ฑ์—์„œ ์ œ์‹œํ•˜๋Š” ๊ฑด์ถ•์žฌ๋ฃŒ์˜ ์ˆ˜๋ฐ€์„ฑ๋Šฅ ๊ธฐ์ค€์ธ 0.5 kg/m2h0.5๊ณผ ๋น„๊ตํ•  ๋•Œ, ๊ฐœ๋ฐœ๋œ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž… LMC์˜ ์ˆ˜๋ฐ€์„ฑ๋Šฅ์€ ๋งค์šฐ ์šฐ์ˆ˜ํ•œ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค(Lee et al. 2002).

Table 3 Water-tightness obtained from test results

/Resources/kci/JKCI.2018.30.3.325/images/Table_CONCRETE_30_3_10_T3.jpg

์„ ํ–‰์—ฐ๊ตฌ ๊ฒฐ๊ณผ ์žฌ๋ฃŒ์˜ ์ˆ˜๋ฐ€์„ฑ๋Šฅ์€ ๋ผํ…์Šค์˜ ํ•จ์œ ๋Ÿ‰์— ํฌ๊ฒŒ ์˜์กดํ•˜๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, ์ด๋Š” ๋ผํ…์Šค ํ˜ผ์ž…์œผ๋กœ ์ธํ•œ ๋ฏธ์„ธ๊ณต๊ทน์˜ ์ถฉ์ง„ํšจ๊ณผ์™€ ๋”๋ถˆ์–ด ์žฌ๋ฃŒํ‘œ๋ฉด์— ๋ผํ…์Šค ํ•„๋ฆ„๋ง‰์ด ํ˜•์„ฑ๋˜์–ด ์ˆ˜๋ฐ€์„ฑ๋Šฅ์„ ๊ฐœ์„ ํ•˜๋Š” ๊ฒƒ์œผ๋กœ ๋ถ„์„๋œ๋‹ค(Kim et al. 2001; Joo et al. 2009).

4.2 ๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„

๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ ์‹คํ—˜์€ L15-F0.3์— ๋Œ€ํ•ด ๋™๊ฒฐ์œตํ•ด ๋ฐ˜๋ณต์ฃผ๊ธฐ 300๋ฒˆ์งธ ์‚ฌ์ดํด๊นŒ์ง€ ๋ฐ˜๋ณต ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ์‹คํ—˜ ๊ฒฐ๊ณผ ์ƒ๋Œ€ ๋™ ํƒ„์„ฑ๊ณ„์ˆ˜ /Resources/kci/JKCI.2018.30.3.325/images/PIC32E2.gif๋Š” ํ‰๊ท  87.4 %๋กœ ๋‚ด๊ตฌ์„ฑ ์ €ํ•˜๋Š” ๋ฐœ๊ฒฌ๋˜์ง€ ์•Š์•˜๋‹ค. ๋ณดํ†ต ์ฝ˜ํฌ๋ฆฌํŠธ์—์„œ๋Š” ๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ์„ ํ–ฅ์ƒ์‹œํ‚ค๊ธฐ ์œ„ํ•˜์—ฌ ์ผ์ • ์ˆ˜์ค€์˜ ๊ณต๊ธฐ๋Ÿ‰ ํ™•๋ณด๋ฅผ ๋ชฉํ‘œ๋กœ AE์ œ ๋“ฑ์„ ์ฒจ๊ฐ€ํ•˜์ง€๋งŒ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ฒฝ์šฐ ์—ฌํƒ€ ํ˜ผํ™”์ œ์˜ ํˆฌ์ž… ์—†์ด๋„ ๊ณต๊ธฐ๋Ÿ‰์˜ ํ™•๋ณด๊ฐ€ ์ˆ˜์›”ํ•˜๋ฉฐ ๋ผํ…์Šค์˜ ํ•„๋ฆ„๋ง‰ ํšจ๊ณผ๋กœ ์ธํ•ด ํˆฌ์ˆ˜์ €ํ•ญ์„ฑ์ด ํ–ฅ์ƒ๋˜์–ด ๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ์ด ๊ฐœ์„ ๋˜๋Š” ๊ฒƒ์œผ๋กœ ์‚ฌ๋ฃŒ๋œ๋‹ค(Kim et al. 2001).

๋ณธ ์‹คํ—˜์—์„œ ์‚ฌ์šฉ๋œ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž… ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์—์„œ๋Š” ๊ธฐ์กด ์‚ฌ์šฉ๋˜๋Š” ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ ๋ณด๋‹ค ๋ผํ…์Šค ํ˜ผ์ž…๋Ÿ‰์ด ์ ˆ๋ฐ˜ ์ดํ•˜๋กœ ๊ฐ์†Œํ•˜๋ฉฐ ๋ฐ˜๋ฉด ์†Œ๋Ÿ‰์˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ ์ถ”๊ฐ€๋กœ ํ˜ผ์ž…ํ•œ๋‹ค. ๋Œ€์šฉ๋Ÿ‰ ์ƒ์‚ฐ ์‹œ ๋ผํ…์Šค์˜ ๊ฐ€๊ฒฉ์ด ๊ณ ๊ฐ€์ด๋ฉฐ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์˜ ๊ฐ€๊ฒฉ์ด ๋ผํ…์Šค ๋ณด๋‹ค ์ €๋ ดํ•˜๊ธฐ ๋•Œ๋ฌธ์—, ๋ณธ ์‹คํ—˜์˜ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž… ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ๊ธฐ์กด์˜ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ๋ณด๋‹ค ๊ฒฝ์ œ์„ฑ์ด ๊ฐœ์„ ๋˜๋Š” ๊ฒƒ์œผ๋กœ ๋ถ„์„๋œ๋‹ค.

์ถ”ํ›„ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž… ์‹œ ๋ผํ…์Šค์˜ ํ•จ์œ ๋Ÿ‰์— ๋”ฐ๋ฅธ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์žฌ๋ฃŒ์„ฑ๋Šฅ, ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์˜ ์ข…๋ฅ˜ ๋ฐ ํ˜•ํƒœ์  ํŠน์„ฑ์ด ์žฌ๋ฃŒ์„ฑ๋Šฅ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ ๋“ฑ์— ๊ด€ํ•œ ๊ทœ๋ช…์ด ์ˆ˜ํ–‰๋  ํ•„์š”๊ฐ€ ์žˆ๋‹ค.

5. ๊ฒฐ    ๋ก 

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์„ฑ๋Šฅ๊ณผ ๋‚ด๊ตฌ์„ฑ๋Šฅ์„ ๊ทœ๋ช…ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๋ผํ…์Šค์˜ ์ค‘๋Ÿ‰๋น„์™€ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ์˜ ๋ถ€ํ”ผ๋น„๋ฅผ ์ฃผ์š” ๋ณ€์ˆ˜๋กœ ํ•˜์—ฌ ์••์ถ•๊ฐ•๋„, ํœจ๊ฐ•๋„, ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ•, ์ˆ˜๋ฐ€์„ฑ๋Šฅ, ๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ ์‹œํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ๋ณธ ์—ฐ๊ตฌ์˜ ์ฃผ์š”๊ฒฐ๊ณผ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™๋‹ค.

1) ์••์ถ•๊ฐ•๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ, ๋ผํ…์Šค 15 %์™€ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ 0.3 % ํ˜ผ์ž…ํ•œ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ฒฝ์šฐ ์žฌ๋ น 7์ผ ๊ฐ•๋„๋Š” ์žฌ๋ น 28์ผ ๋Œ€๋น„ 91 %๋กœ ์กฐ๊ธฐ๊ฐ•๋„ ๋ฐœํ˜„ ํšจ๊ณผ๊ฐ€ ๋งค์šฐ ํฐ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

2) ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํœจ๊ฐ•๋„ ์‹คํ—˜ ๊ฒฐ๊ณผ, ์ž”๋ฅ˜๊ฐ•๋„๋Š” ์ตœ๋Œ€๊ฐ•๋„์˜ 50 %์ด๋‹ค. ํœจ ์ธ์žฅ๊ฐ•๋„ ๊ณ„์‚ฐ๊ฐ’๊ณผ ๋น„๊ตํ•˜๋ฉด, ๋ผํ…์Šค 15 %์™€ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฃฐ 0.3 % ํ˜ผ์ž…ํ•œ ๊ฒฝ์šฐ์—๋Š” 34 % ๋” ํฐ ํœจ๊ฐ•๋„๋ฅผ ๋ณด์˜€๋‹ค.

3) ๊ตฌ์†๊ฑด์กฐ์ˆ˜์ถ• ์‹คํ—˜ ๊ฒฐ๊ณผ, ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ 0.3 % ํ˜ผ์ž…ํ•œ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ์ตœ๋Œ€๊ท ์—ดํญ 0.19 mm์œผ๋กœ ๊ท ์—ด์ œ์–ด์„ฑ๋Šฅ์ด ์šฐ์ˆ˜ํ•œ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

4) ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ˆ˜๋ฐ€์„ฑ๋Šฅ ์‹คํ—˜ ๊ฒฐ๊ณผ, ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ 0.2 % ํ˜ผ์ž…ํ•œ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํ‰๊ท  ๋ฌผ ํก์ˆ˜๊ณ„์ˆ˜ /Resources/kci/JKCI.2018.30.3.325/images/PIC32E3.gif๋Š” 0.165 kg/m2h0.5์ด๊ณ , ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ 0.2 % ํ˜ผ์ž…ํ•œ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํ‰๊ท  ๋ฌผ ํก์ˆ˜๊ณ„์ˆ˜ /Resources/kci/JKCI.2018.30.3.325/images/PIC32E4.gif๋Š” 0.133 kg/m2h0.5๋กœ ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž…-๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ˆ˜๋ฐ€์„ฑ๋Šฅ์€ ์šฐ์ˆ˜ํ•œ ๊ฒƒ์œผ๋กœ ํ™•์ธ๋˜์—ˆ๋‹ค.

5) ๋งˆ์ดํฌ๋กœ ๊ฐ•์„ฌ์œ ๋ฅผ 0.3 % ํ˜ผ์ž…ํ•œ ๋ผํ…์Šค ๊ฐœ์งˆ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ๋™๊ฒฐ์œตํ•ด ๋ฐ˜๋ณต์ฃผ๊ธฐ 300๋ฒˆ์งธ ์‚ฌ์ดํด๊นŒ์ง€ ์ƒ๋Œ€ ๋™ ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ 87.4 %๋กœ ๋™๊ฒฐ์œตํ•ด์ €ํ•ญ์„ฑ์ด ์šฐ์ˆ˜ํ•œ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

Acknowledgements

์ด ๋…ผ๋ฌธ์€ 2017๋…„๋„ ์ •๋ถ€(๊ต์œก๋ถ€)์˜ ์žฌ์›์œผ๋กœ ํ•œ๊ตญ์—ฐ๊ตฌ์žฌ๋‹จ์˜ ์ง€์›์„ ๋ฐ›์•„ ์ˆ˜ํ–‰๋œ ๊ธฐ์ดˆ์—ฐ๊ตฌ์‚ฌ์—…์ด๋‹ค(No. 2017R1D1 A1B04033611).

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