(Khaliunaa Darkhanbat)
1
νμΈμ±
(Inwook Heo)
2
μ΅μΉνΈ
(Seung-Ho Choi)
3
κΉκ°μ
(Kang Su Kim)
4β
-
μ νμ,μμΈμ립λνκ΅ κ±΄μΆκ³΅νκ³Ό μ€λ§νΈμν°μ΅ν©μ 곡 λ°μ¬κ³Όμ
-
μ νμ,μμΈμ립λνκ΅ λμλ°©μ¬μμ μ°κ΅¬μ λ°μ¬νμ°κ΅¬μ
-
μ νμ,μμΈμ립λνκ΅ λ°©μ¬κ³΅νκ³Ό μ‘°κ΅μ
-
μ νμ,μμΈμ립λνκ΅ κ±΄μΆκ³΅νκ³Ό μ€λ§νΈμν°μ΅ν©μ 곡 κ΅μ, κ΅μ μ μ
Copyright Β© The Korea Institute for Structural Maintenance and Inspection
ν€μλ
μ½ν¬λ¦¬νΈ, λκ²°μ΅ν΄, μ νμ±λ₯, μΈκ³΅μ κ²½λ§, μλλνμ±κ³μ
Key words
Concrete, Freeze-thaw, Resistance, Artificial neural network (ANN), Relative dynamic modulus of elasticity(RDME)
1. μ λ‘
κ΅λ΄ 겨μΈμ² μ¨λμ λ³ν νμ΄ ν¬κΈ° λλ¬Έμ μ½ν¬λ¦¬νΈ ꡬ쑰물μ μ£ΌκΈ°μ μΈ λκ²°μ΅ν΄ νΌν΄λ₯Ό κ²½ννκ³ μλ€. Fig. 1μ λνλΈ λ°μ κ°μ΄ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ λ΄κ΅¬μ± μ ννμμ μ£Όλ‘ λ΄λΆ λ―ΈμΈκ· μ΄ λ° νλ©΄λ°λ¦¬μ κ°μ λ¬Έμ λ₯Ό λ°μμν¨λ€. μ΄λ‘ μΈνμ¬ κ΅¬μ‘°λ¬Όμ
λ―Έκ΄μ΄ μμλλ©°, λΆμ¬μ λ΄λ ₯μ΄ κ°μν¨μΌλ‘μ¨ κ΅¬μ‘°λ¬Όμ μλͺ
μ΄ λ¨μΆλ μ μλ€(Neville, 1995). λκ²°μ΅ν΄ νΌν΄λ₯Ό μ
μ μ½ν¬λ¦¬νΈ ꡬ쑰물μ λ΄κ΅¬μ±λ₯ μ νλ‘ μΈν μ¬νμ λΉμ©μ΄ μ§μμ μΌλ‘ λ°μλκ³ μλ κ²μ΄λ€. μ½ν¬λ¦¬νΈ λ°°ν©μ λ°λ₯Έ λκ²°μ΅ν΄ μ νμ±λ₯μ
νμ
νκΈ° μν΄μλ μ€νμ΄ νμμ μ΄μ§λ§ μ΄λ₯Ό μν΄μλ μλΉν μκ°κ³Ό λΉμ©μ΄ μμλλ€. λ°λΌμ, μ μνλ©΄μλ μ λ’°μ±μ΄ λμ μ½ν¬λ¦¬νΈ λ°°ν©μ λ°λ₯Έ λκ²°μ΅ν΄
μ νμ±λ₯ νκ°λͺ¨λΈμ κ°λ°μ ν΅νμ¬ μ΄λ¬ν λ¬Έμ μ μ 극볡ν μ μλ€.
Lee(2018)λ μ½ν¬λ¦¬νΈμ νμ°νμ λκ²°μ΅ν΄μ λν 볡ν©μ΄νλ₯Ό νκ°νμλ€. Choi(2021)λ λκ²°μ΅ν΄ μΈμ΄ν΄ μμ λ°λ₯Έ μμΆκ°λ, λ°λ°κ²½λ, μλλνμ±κ³μ λ° μ΄μν λΉμ νμ±μ μΈ‘μ νμμΌλ©°, SEMμ ν΅νμ¬ λ―ΈμΈκ· μ΄μ λΆμνμλ€. Yoon(2017)μ λμ μ½ν¬λ¦¬νΈ 보λ₯Ό λμμΌλ‘ Pν, Sν, Rνμ νμ€ μλλ₯Ό μΈ‘μ νκ³ κ° νμ μ’
λ₯λ³ μλμ λν ν΅κ³μ λΆν¬λ₯Ό μ‘°μ¬νμλ€. You(2010)λ μ€νμ νμ©νμ¬ FRP 볡ν©μ²΄μ λ΄κ΅¬νΉμ±μ νμ
νμμΌλ©°, μ€κ³μ λ°μνκΈ° μν΄μ FRP 볡ν©μ²΄μ λ΄κ΅¬μ± μ νμ λν λ°μ΄ν°λ² μ΄μ€λ₯Ό ꡬμΆνμλ€.
μ΅κ·Όμλ μ½ν¬λ¦¬νΈ λ΄κ΅¬μ± νκ° μ€νλΏλ§ μλλΌ, λ΄κ΅¬μ± νκ°λͺ¨λΈμ κ΄ν μ°κ΅¬λ νλ°ν μνλκ³ μλ€(Yan, 2020).
μ΅κ·Ό 곡ν λΆμΌμμλ 볡μ‘ν λ©μ»€λμ¦κ³Ό ν° λΆνμ€μ±μ κ°μ§ μ
λ ₯ λ° μΆλ ₯ λ³μλ‘ μ΄λ£¨μ΄μ§ λ¬Έμ λ₯Ό ν΄κ²°νκΈ° μνμ¬ μΈκ³΅μ κ²½λ§(Artificial Neural
Network, ANN) λͺ¨λΈμ νμ©ν μ°κ΅¬κ° μ κ·Ήμ μΌλ‘ μ§νλκ³ μλ€(Nimlyat, 2017; Baek, 2010; Stankovi, 2018; Popescu, 2006). μΈκ³΅μ κ²½λ§μ λ°μ΄ν°λ² μ΄μ€λ₯Ό νμ©νμ¬ μ
λ ₯μΈ΅κ³Ό μΆλ ₯μΈ΅ μ¬μ΄μ 볡μ‘ν λΉμ νμ κ΄κ³λ₯Ό νμ΅νκ³ μ΄λ₯Ό ν΅νμ¬ κ²°κ³Όκ°μ μ€μ°¨λ₯Ό μ΅μνν μ μλ€. λν,
μ΄λ―Έ νμ΅λ μΈκ³΅μ κ²½λ§ λͺ¨λΈμ μ
λ ₯κ°μ΄ μ£Όμ΄μ§λ©΄ μ μνκ² μΆλ ₯κ°μ μμΈ‘ν μ μλ€λ μ₯μ μ΄ μλ€. μ΄λ¬ν μΈκ³΅μ κ²½λ§ μκ³ λ¦¬μ¦μ μ½ν¬λ¦¬νΈ λκ²°μ΅ν΄ μ νμ±λ₯
νκ°μ μ μ©νλ©΄ μ½ν¬λ¦¬νΈ λ°°ν© λ°μ΄ν°λ₯Ό νμ©νμ¬ μ€μκ°μΌλ‘ μ νμ±λ₯μ μ°μ ν μ μμ κ²μ΄λ€.
λ°λΌμ, μ΄ μ°κ΅¬μμλ λκ²°μ΅ν΄ μ νμ±λ₯ νκ°λͺ¨λΈμ κ°λ°νκΈ° μνμ¬ κΈ°μ‘΄ μ°κ΅¬(Yu, 2017; Shang, 2009; Shang, 2013; Wu, 2016; Duan, 2013; Janssen, 1994)λ₯Ό κΈ°λ°μΌλ‘ μ½ν¬λ¦¬νΈμ λν λκ²°μ΅ν΄ μ€ν λ°μ΄ν°λ² μ΄μ€λ₯Ό ꡬμΆνμμΌλ©°, μΈκ³΅μ κ²½λ§ λͺ¨λΈμ νμ©νμ¬ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ νκ°λͺ¨λΈμ
κ°λ°νμλ€. λν, νκ·λΆμμ μννμ¬ λκ²°μ΅ν΄ μ νμ±λ₯ μ°μ μμ μ μνμλ€.
Fig. 1 Types of freeze-thaw damage
2. λκ²°μ΅ν΄ μ νμ±λ₯ νκ°λͺ¨λΈ
2.1 λ°μ΄ν°λ² μ΄μ€ ꡬμΆ
λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ νκ°λͺ¨λΈμ κ°λ°μ μνμ¬ μ½ν¬λ¦¬νΈμ λν λκ²°μ΅ν΄ μ€ν κ΄λ ¨ λ°μ΄ν°λ² μ΄μ€λ₯Ό ꡬμΆνμλ€. κΈ°μ‘΄ μ°κ΅¬(Yu, 2017; Shang, 2009; Shang, 2013; Wu, 2016; Duan, 2013; Cho, 2007; Janssen, 1994)λ₯Ό ν λλ‘ μ΄ 196κ°μ λ°μ΄ν°λ² μ΄μ€λ₯Ό ꡬμΆνμλ€. Table 1μλ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ λ°μ΄ν°λ² μ΄μ€ ꡬμΆμ νμ©λ μ°Έκ³ λ¬Ένμ λν μ 보λ₯Ό λνλ΄μμΌλ©°, Table 2μλ λ°μ΄ν°λ² μ΄μ€ ꡬμΆμ νμ©λ μν체μ μΌλΆλ₯Ό λνμ μΌλ‘ λνλ΄μλ€. λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ νκ°λͺ¨λΈμ μΌλ°μ μΌλ‘ μ¬μ©λλ μ½ν¬λ¦¬νΈ
λ°°ν©μ μ°κ΅¬λ²μλ‘ νμ νμμΌλ©°, νΉμ νΌνμ λ±μ μ¬μ©ν λ°μ΄ν°λ₯Ό μ μΈνμλ€. λ°λΌμ, νκ°λͺ¨λΈμ μ
λ ₯λ³μλ μ½ν¬λ¦¬νΈ μ νμ±λ₯μ ν° μν₯μ λ―ΈμΉλ€κ³
μλ €μ§ λ¬Ό/μλ©νΈ λΉ, μ골μ¬λΉ, 곡기λ, μμΆκ°λ λ° λκ²°-μ΅ν΄ μ¬μ΄ν΄ μλ‘ μ€μ νμλ€. λν, μΆλ ₯λ³μλ μ½ν¬λ¦¬νΈ λκ²°μ΅ν΄ μ νμ±μ νλ¨ν μ
μλ μλλνμ±κ³μ(Relative Dynamic Modulus of Elasticity, RDME)λ‘ μ€μ νμλ€. μλλνμ±κ³μλ μ½ν¬λ¦¬νΈκ° μ¨λλ³νμ
λ°λ₯Έ λ―ΈμΈν κ· μ΄μ μ΅μννκ³ νμ±μ μΌλ‘ μ μ§ν μ μλ λ₯λ ₯μ μλ―Ένλ κ²μΌλ‘ μ΄ν΄λκ³ μμΌλ©°, μ½ν¬λ¦¬νΈμ λ΄κ΅¬μ± μ νλ₯Ό νκ°νλ κ°μ₯ μ€μν μ§νλ‘
λ리 νμ©λκ³ μλ€(Yu, 2017; Cho, 2007; Zhao, 2013).
Table 1 Information of training database from literature
*GB/T 50082-2009 is a Chinese standard, whose details are very similar to ASTM Standard
C666.
Table 2 Database of freeze-thaw resistance
No.
|
Water-cement ratio, w/c
|
Sand-aggregate ratio, s/a
|
Air content (%)
|
Compressive strength, fc (MPa)
|
Number of freeze-thaw cycles
|
Relative dynamic modulus of elasticity, RDME (%)
|
1
|
0.320
|
0.613
|
3.1
|
81.1
|
50
|
98
|
2
|
0.320
|
0.613
|
3.1
|
81.1
|
100
|
98
|
3
|
0.320
|
0.613
|
3.1
|
81.1
|
150
|
98
|
4
|
0.320
|
0.613
|
3.1
|
81.1
|
200
|
93
|
5
|
0.250
|
0.613
|
2.9
|
91.4
|
50
|
101
|
6
|
0.250
|
0.613
|
2.9
|
91.4
|
100
|
98
|
7
|
0.250
|
0.613
|
2.9
|
91.4
|
150
|
97
|
8
|
0.250
|
0.613
|
2.9
|
91.4
|
200
|
96
|
9
|
0.320
|
0.613
|
3.2
|
74.2
|
50
|
100
|
10
|
0.250
|
0.613
|
3.2
|
74.2
|
100
|
98
|
2.2 μΈκ³΅μ κ²½λ§ νμ΅
μΈκ³΅μ κ²½λ§μ λ°μ΄ν°λ² μ΄μ€λ₯Ό κΈ°λ°μΌλ‘ νμ¬ μ
λ ₯λ³μμ μΆλ ₯λ³μ μ¬μ΄μ 볡μ‘ν λΉμ νμ κ΄κ³λ₯Ό νμ΄κ°λ λ°μ νμ©ν μ μλ€. μΈκ³΅μ κ²½λ§ λͺ¨λΈμ μ
λ ₯μΈ΅,
μλμΈ΅ λ° μΆλ ₯μΈ΅μΌλ‘ ꡬμ±λμ΄ μλ€. μΈκ³΅μ κ²½λ§ λͺ¨λΈμλ λ΄λ°μ΄λΌλ μ 보μ²λ¦¬ μΈμκ° μ‘΄μ¬νλ©°, λ΄λ°μ μ
λ ₯μΈ΅κ³Ό μΆλ ₯μΈ΅ μ¬μ΄ κ΄κ³μ κ°λλ₯Ό νννλ
μλ‘ λ€λ₯Έ κ°μ€μΉ(weight) λ° μμΉ(bias)λ‘ μ°κ²°λμ΄ μλ€. νμ΅ κ³Όμ μ κ°μ€μΉ κ°μ μ§μμ μΌλ‘ μμ νμ¬ μ€μ°¨λ₯Ό μ΅μννλ λ°©ν₯μΌλ‘ μ§νλλ€(Russel, 2010; Cho, 2015; Cho, 2017; Kang, 2019; Darkhanbat 2021).
Fig. 2μ λνλΈ λ°μ κ°μ΄ μΈκ³΅μ κ²½λ§ νμ΅μμ μ¬μ©λ μ
λ ₯μΈ΅μ λ¬Ό/μλ©νΈ λΉ, μ골μ¬λΉ, 곡기λ, μμΆκ°λ λ° λκ²°μ΅ν΄ μ¬μ΄ν΄ μλ‘ 5κ°, μλμΈ΅μ 9κ°μ
λ΄λ°, μΆλ ₯μΈ΅μ μλλνμ±κ³μλ‘ κ΅¬μ±νμλ€. λ°μ΄ν°λ² μ΄μ€ μ€ μΈκ³΅μ κ²½λ§ λͺ¨λΈμ νμ΅, κ²μ¦ λ° νμΈμ νμ©λ λ°μ΄ν°μ λΆλ°°λ κ°
κ° 70%, 15%μ 15%λ‘ κ³ννμλ€. Fig. 3μ λνλΈ λ°μ κ°μ΄ μ
λ ₯μΈ΅μμ μλμΈ΅μΌλ‘μ μ λ¬μ μν νμ±ν ν¨μλ‘ μ곑νμ νΈ μκ·Έλͺ¨μ΄λ(Hyperbolic tangent sigmoid) ν¨μλ₯Ό
νμ©νμμΌλ©°, μΆλ ₯μΈ΅μμλ μμμ νν¨μ(Pure linear function)λ₯Ό μ μ©νμ¬ μΈκ³΅μ κ²½λ§ νμ΅μ μννμλ€(Hagan, 1994; Lee, 2016; Nielsen, 1989).
μ΄ μ°κ΅¬μμ μ μν μκ³ λ¦¬μ¦μ κΈ°λ°μΌλ‘ μμΈ‘λ κ²°κ³Όκ°($t_{n}$)μ μλμ κ°μ ν¨μλ‘ ννν μ μλ€.
μ¬κΈ°μ, $p_{n}$μ μ κ·νλ μ
λ ₯κ°, $W_{1}$, $W_{2}$ λ° $b_{1}$, $b_{2}$λ κ°κ° κ°μ€μΉμ μμΉ, $f_{1}$μ
μ
λ ₯μΈ΅κ³Ό μλμΈ΅ κ°μ νμ±ν¨μλ₯Ό, $f_{2}$λ μλμΈ΅κ³Ό μΆλ ₯μΈ΅ κ°μ νμ±ν¨μλ₯Ό λνλΈλ€. Table 3μλ λκ²°μ΅ν΄ μ νμ±λ₯μ μΈκ³΅μ κ²½λ§ νμ΅κ³Όμ μ νμ©λ λ°μ΄ν°λ€μ μ΅λκ°κ³Ό μ΅μκ°μ λνλ΄μλ€.
Fig. 2 Freeze-thaw resistance prediction model
Table 3 Range of input parameters and RDME
Parameters
|
Min
|
Max
|
Water-cement ratio, w/c
|
0.1
|
0.6
|
Sand-aggregate ratio, s/a
|
0.06
|
0.82
|
Air content (%)
|
1.1
|
7.0
|
Compressive strength, fc (MPa)
|
14.0
|
92.7
|
Number of freeze-thaw cycles
|
10.0
|
1143.0
|
Relative dynamic modulus of elasticity, RDME (%)
|
25.1
|
101.0
|
2.3 μΈκ³΅μ κ²½λ§ νμ΅κ²°κ³Ό
μ΄ μ°κ΅¬μμλ μΈκ³΅μ κ²½λ§ λͺ¨λΈ λ° νκ·μμ μ νλ νκ°μ§νλ‘ κ²°μ κ³μμ νκ· μ€μ°¨μ¨μ νμ©νμλ€. κ²°μ κ³μ(R2)λ μ£Όμ΄μ§ λ°μ΄ν°μ λν νκ· λͺ¨λΈμ
μ€λͺ
λ ₯μ λνλ΄λ μ§νμ΄λ©°, μΌλ°μ μΌλ‘ κ²°μ κ³μκ° λμμλ‘ λͺ¨λΈμ΄ μ£Όμ΄μ§ λ°μ΄ν°λ₯Ό λ μ μ€λͺ
νλ€κ³ ν μ μλ€. λ€λ§, λΆμΌ λ° μν©μ λ°λΌ μΈκ³΅μ κ²½λ§
λͺ¨λΈμ μꡬνλ μ νλκ° ν¬κ² λ¬λΌμ§λ©°, μΈκ³΅μ κ²½λ§ λ° μ½ν¬λ¦¬νΈμ λκ²°μ΅ν΄ κ΄λ ¨ μ°κ΅¬μλ€(In, 2013)μ κ²°μ κ³μκ° 0.70 μ΄μμ΄λ©΄ μλΉν λμ μ νλλ₯Ό κ°λλ€κ³ λ³΄κ³ νκ³ μλ€. λν, μ΄ μ°κ΅¬μμλ μ μ μΈκ³΅μ κ²½λ§ λͺ¨λΈμ μ±λ₯μ νκ°νκΈ° μν΄ μΆκ°μ μΌλ‘
νκ· μ€μ°¨μ¨μ νμ©νμμΌλ©°, νκ· μ€μ°¨μ¨μ κ²½μ°μλ κ²°μ κ³μμ λ§μ°¬κ°μ§λ‘ μ νλλ₯Ό ν보νμλ€κ³ νλ¨ν μ μλ μ€μ°¨μ¨μ λΆμΌ, λ°μ΄ν°μ λΆν¬ λ° νκ²½μ
λ°λΌ ν¬κ² λ¬λΌμ§λ€. μ½ν¬λ¦¬νΈμ λκ²°μ΅ν΄ κ΄λ ¨ μ°κ΅¬μλ€(Yang, 2002)μ μλλνμ±κ³μ νκ°λͺ¨λΈμ μ€μ°¨μ¨μ΄ μ½ 15% μ΄νμΈ κ²½μ°μ μΆ©λΆν μ±λ₯μ ν보νμλ€κ³ λ³΄κ³ νκ³ μμΌλ©°, μ μλ€μ μ΄λ₯Ό μ°Έκ³ νμ¬ μΈκ³΅μ κ²½λ§ λͺ¨λΈ
λ° νκ·μμ νκ°μ§νλ‘ νμ©νμλ€.
μΈκ³΅μ κ²½λ§ λͺ¨λΈμ νμ΅κ³Όμ μ ν΅νμ¬ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ μμΈ‘ λͺ¨λΈμ κ°μ€μΉμ μμΉλ₯Ό λμΆνμμΌλ©°, Table 4μ λνλ΄μλ€. Fig. 4 λ° Table 5μλ μ μ μΈκ³΅μ κ²½λ§ λͺ¨λΈμ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ νμ΅κ²°κ³Όλ₯Ό λνλΈ κ²μ΄λ€. νμ΅κ²°κ³Όμ κ²°μ κ³μ(Coefficient of determination,
R2)λ 0.93, νκ· μ€μ°¨μ¨μ μ½ 5%λ₯Ό 보μμΌλ©°, μ΄λ μΈκ³΅μ κ²½λ§ λͺ¨λΈμ΄ λ§€μ° μ°μν νμ΅κ²°κ³Όλ₯Ό λμΆνμλ€λ κ²μ μλ―Ένλ€.
Fig. 4 ANN training results
Table 4 Weight and bias
Hidden neurons
|
Bias 1 (b1)
|
Weight 1 (W1)
|
Weight 2 (W2)
|
Water-cement ratio, w/c
|
Sand-aggregate ratio, s/a
|
Air content (%)
|
Compressive strength, fc (MPa)
|
Number of freeze-thaw cycles
|
Relative dynamic modulus of elasticity, RDME (%)
|
1
|
-1.409
|
-0.428
|
-3.987
|
-2.584
|
1.339
|
-0.784
|
2.600
|
2
|
4.206
|
2.227
|
-1.698
|
-0.059
|
0.090
|
-4.733
|
-6.563
|
3
|
-2.395
|
-2.257
|
-3.958
|
1.121
|
-2.783
|
-2.419
|
4.783
|
4
|
3.133
|
0.138
|
0.570
|
0.910
|
-2.289
|
1.299
|
-0.204
|
5
|
-1.988
|
0.689
|
3.581
|
3.100
|
0.219
|
1.519
|
-0.727
|
6
|
0.850
|
-4.592
|
-1.342
|
2.144
|
1.214
|
-4.618
|
-1.740
|
7
|
1.570
|
-1.840
|
-0.081
|
-1.733
|
4.216
|
-1.062
|
0.921
|
8
|
3.692
|
-0.314
|
1.702
|
2.181
|
2.961
|
-1.665
|
3.654
|
9
|
-2.460
|
-1.799
|
1.044
|
0.917
|
-1.357
|
1.799
|
-1.561
|
Bias 2 (b2) = 1.704
|
Table 5 Training results of ANN model
Case No.
|
Relative dynamic modulus of elasticity,
RDME (%)
[Experiment]
|
Relative dynamic modulus of elasticity,
RDME (%)
[Prediction]
|
Error, %
|
1
|
98
|
98.94
|
0.96
|
2
|
98
|
96.20
|
1.84
|
3
|
98
|
92.70
|
5.41
|
4
|
93
|
87.73
|
5.66
|
5
|
93
|
84.38
|
9.27
|
6
|
81
|
80.23
|
0.95
|
7
|
72
|
68.86
|
4.36
|
8
|
56
|
61.47
|
9.77
|
9
|
48
|
53.10
|
10.63
|
10
|
101
|
102.28
|
1.27
|
AVG.
|
4.91
|
2.4 μΈκ³΅μ κ²½λ§ κ²μ¦
λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ νκ°λͺ¨λΈμ κ²μ¦μ μ μ μΈκ³΅μ κ²½λ§ λͺ¨λΈμ νμ΅μ νμ©λμ§ μμ μ°Έκ³ λ¬Ένμμ μμ§ν 20κ°μ μλ‘μ΄ λ°μ΄ν°λ‘
ꡬμ±νμ¬ μννμλ€(Trottier, 2022; Choi, 1997; Shang, 2012). Fig. 5 λ° Table 6μ λνλΈ λ°μ κ°μ΄ κ²μ¦ κ²°κ³Όμ νκ· μ€μ°¨μ¨μ΄ 10.4%λ‘ λνλ¬μΌλ©°, κ²°μ κ³μ(R2)λ 0.70μΌλ‘ λνλμ μ μλ λκ²°μ΅ν΄ μ νμ±λ₯ νκ°λͺ¨λΈμ΄
λμ μ νλλ₯Ό ν보ν κ²μΌλ‘ νλ¨λλ€.
Fig. 5 ANN validation results
Table 6 Validation results of ANN model
No.
|
Water-cement ratio, w/c
|
Sand-aggregate ratio, s/a
|
Air content (%)
|
Compressive strength, fc (MPa)
|
Number of freeze-thaw cycles
|
Relative dynamic modulus of elasticity, %
(Experiment)
|
Relative dynamic modulus of elasticity, %
(Predicted)
|
Error
(%)
|
1
|
0.35
|
0.51
|
6.5
|
19
|
100
|
65.3
|
60.4
|
7.5
|
2
|
0.35
|
0.51
|
6.5
|
19
|
150
|
52.8
|
66.2
|
25.4
|
3
|
0.35
|
0.53
|
6.5
|
20
|
50
|
78.5
|
70.9
|
9.6
|
4
|
0.35
|
0.53
|
6.5
|
20
|
100
|
67.2
|
75.3
|
11.9
|
5
|
0.35
|
0.52
|
6.5
|
19
|
50
|
82.4
|
61.4
|
25.4
|
6
|
0.35
|
0.53
|
6.5
|
21
|
50
|
81.9
|
74.4
|
9.2
|
7
|
0.35
|
0.53
|
6.5
|
21
|
100
|
69.4
|
78.1
|
12.4
|
8
|
0.35
|
0.71
|
6.5
|
26
|
50
|
97.1
|
112.9
|
16.3
|
9
|
0.35
|
0.73
|
6.5
|
27
|
50
|
114.1
|
114.2
|
0.1
|
10
|
0.35
|
1.09
|
6.5
|
41
|
50
|
97.3
|
110.2
|
13.3
|
11
|
0.35
|
1.14
|
6.5
|
42
|
150
|
67.0
|
65.9
|
1.6
|
12
|
0.35
|
1.11
|
6.5
|
62
|
150
|
68.5
|
63.0
|
8.0
|
13
|
0.45
|
0.54
|
2
|
26.5
|
300
|
76.8
|
87.4
|
13.8
|
14
|
0.45
|
0.54
|
2
|
26.5
|
258
|
83.2
|
79.0
|
5.0
|
15
|
0.45
|
0.54
|
2
|
26.5
|
268
|
83.1
|
81.1
|
2.5
|
16
|
0.45
|
0.54
|
2
|
26.5
|
276
|
80.5
|
82.6
|
2.6
|
17
|
0.45
|
0.54
|
2
|
26.5
|
280
|
79.9
|
83.5
|
4.5
|
18
|
0.45
|
0.54
|
2
|
26.5
|
292
|
79.8
|
85.9
|
7.6
|
19
|
0.550
|
0.49
|
1.9
|
42.5
|
25
|
74.1
|
70.5
|
4.9
|
20
|
0.550
|
0.49
|
1.9
|
42.5
|
50
|
46.8
|
59.1
|
26.3
|
AVG.
|
10.40
|
3. νκ·λΆμμ ν΅ν λκ²°μ΅ν΄ μ νμ±λ₯ νκ°λͺ¨λΈ
λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ μ°μ μμ λ³μλ₯Ό μ€μ νκΈ° μνμ¬ κ° λ³μμ λν μ€μλ λΆμμ μννμλ€. Fig. 6μ λνλΈ λ°μ κ°μ΄ 곡기λ, λ¬Ό/μλ©νΈλΉ, μμΆκ°λ λ° μ골μ¬λΉ μμλ‘ λκ²°μ΅ν΄ μ νμ±λ₯μ ν° μν₯μ λ―ΈμΉλ κ²μΌλ‘ λνλ¬λ€.
μ€μλ λΆμκ³Ό ν¨κ» Fig. 7μ λνλΈ λ°μ κ°μ΄ λ¬Ό/μλ©νΈλΉ, μ골μ¬μ¨, 곡기λ, μ½ν¬λ¦¬νΈμ μμΆκ°λ λ° λκ²°μ΅ν΄ μ¬μ΄ν΄ μμ μλλνμ±κ³μμ λν μκ΄κ΄κ³λ₯Ό λΆμνμμΌλ©°,
μκ΄κ΄κ³ λΆμ κ²°κ³Όλ₯Ό κΈ°λ°μΌλ‘ νκ·λΆμμ ν΅ν΄ μ (2)μ κ°μ λκ²°μ΅ν΄ μ νμ±λ₯ ($RDME$) νκ°μμ λ€μκ³Ό κ°μ΄ λμΆνμλ€.
μ¬κΈ°μ, Aλ 곡기λ, π½λ μ골μ¬μ¨, fcλ μμΆκ°λ, πΌλ λ¬Ό/μλ©νΈλΉ, Nμ λκ²°μ΅ν΄ μ¬μ΄ν΄ μλ₯Ό μλ―Ένλ€. μ (2)μ μν μ°μ κ° μ€νκ²°κ³Όκ°μ λΉκ΅ν κ²°κ³Ό, Table 7κ³Ό Fig. 8μ λνλΈ λ°μ κ°μ΄ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ νκ°μμ νκ· μ€μ°¨μ¨κ³Ό κ²°μ κ³μ(R2)λ κ°κ° 11.8%μ 0.72λ‘ λνλ¬λ€.
Fig. 6 Importance evaluation results
Fig. 7 Correlation for each variables with RDME
Fig. 8 Results of Resistance evaluation equation
Table 7 Comparison between equation with experiment
No.
|
Water-cement ratio, w/c
|
Sand-aggregate ratio, s/a
|
Air content (%)
|
Compressive strength, fc (MPa)
|
Number of freeze-thaw cycles
|
Relative dynamic modulus of elasticity, %
(Experiment)
|
Relative dynamic modulus of elasticity, %
(Equation)
|
Error
(%)
|
πΌ
|
π½
|
A
|
fck
|
N
|
RDME
|
RDME
|
1
|
0.320
|
0.613
|
3.1
|
81.1
|
50
|
98.0
|
100.1
|
2.2
|
2
|
0.320
|
0.613
|
3.1
|
81.1
|
300
|
72.0
|
70.0
|
2.8
|
3
|
0.250
|
0.613
|
2.9
|
91.4
|
150
|
97.0
|
99.7
|
2.8
|
4
|
0.250
|
0.613
|
2.9
|
91.4
|
200
|
96.0
|
94.2
|
1.9
|
5
|
0.250
|
0.613
|
2.9
|
91.4
|
225
|
95.0
|
92.0
|
3.2
|
6
|
0.250
|
0.613
|
2.9
|
91.4
|
250
|
92.0
|
90.1
|
2.1
|
7
|
0.400
|
0.600
|
4
|
40
|
25
|
95.1
|
95.6
|
0.5
|
8
|
0.400
|
0.600
|
4
|
40
|
50
|
86.6
|
83.2
|
3.9
|
9
|
0.400
|
0.600
|
4
|
40
|
150
|
68.3
|
66.8
|
2.2
|
10
|
0.550
|
0.539
|
4
|
55
|
10
|
96.2
|
89.9
|
6.5
|
AVG.
|
11.8
|
4. κ²° λ‘
μ΄ μ°κ΅¬μμλ κΈ°μ‘΄ μ°κ΅¬λ₯Ό ν λλ‘ μ½ν¬λ¦¬νΈ λκ²°μ΅ν΄ μ€ν λ°μ΄ν°λ² μ΄μ€λ₯Ό ꡬμΆνμμΌλ©°, μ΄λ₯Ό νμ©νμ¬ μΈκ³΅μ κ²½λ§ νκ°λͺ¨λΈ λ° νκ·λΆμ μ°μ μμ μ μνμλ€.
μ΄ μ°κ΅¬λ₯Ό ν΅νμ¬ λ€μκ³Ό κ°μ κ²°λ‘ μ μ»μ μ μμλ€.
1. ꡬμΆλ λ°μ΄ν°λ² μ΄μ€λ₯Ό κΈ°λ°μΌλ‘ μΈκ³΅μ κ²½λ§ λͺ¨λΈμ νμ©νμ¬ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ νκ°λͺ¨λΈμ λμΆνμλ€. λμΆλ μΈκ³΅μ κ²½λ§ κΈ°λ°
μ½ν¬λ¦¬νΈ λκ²°μ΅ν΄ μ νμ±λ₯ νκ°λͺ¨λΈμ νκ· μ€μ°¨μ¨ λ° κ²°μ κ³μλ κ°κ° 10.4% λ° 0.70λ‘ λνλ νκ°λͺ¨λΈμ΄ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯μ
λ§€μ° μ°μν μ νλλ‘ νκ°νλ κ²μΌλ‘ νλ¨λλ€.
2. λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ μ°μ μμ λ³μλ₯Ό μ€μ νκΈ° μνμ¬ κ° λ³μμ λν μ€μλ λΆμμ μννμλ€. 곡기λ(μ€μλ: 0.30),
λ¬Ό/μλ©νΈλΉ(μ€μλ: 0.23), μμΆκ°λ(μ€μλ: 0.15) λ° μ골μ¬λΉ(μ€μλ: 0.13) μμλ‘ λκ²°μ΅ν΄ μ νμ±λ₯μ λ―ΈμΉλ μν₯μ΄ ν° κ²μΌλ‘
λνλ¬λ€.
3. νκ·λΆμμ ν΅ν΄ λμΆλ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯ μ°μ μμ νκ· μ€μ°¨μ¨κ³Ό κ²°μ κ³μ(R2)λ κ°κ° 11.8%μ 0.72λ‘ λνλμ,
μ€μ©μ μ΄λ©΄μλ λΉκ΅μ μ°μν μ νλλ₯Ό ν보ν κ²μΌλ‘ νλ¨λλ€.
4. μ΄ μ°κ΅¬μμλ λκ²°μ΅ν΄ μμ©μ λ°λ μ½ν¬λ¦¬νΈμ μ νμ±λ₯μ ν° μν₯μ λ―ΈμΉλ€κ³ μλ €μ§ νμμ μΈ λ³μλ§μ ν λλ‘ νκ°λͺ¨λΈμ μ μνμμ§λ§, μΆν λ€μν
νΌνμ μ λν λ³μλ₯Ό μΆκ°ν¨μΌλ‘μ¨ μ μλͺ¨λΈμ μ μ©λ²μκ° λμ± νλλ κ²μΌλ‘ κΈ°λλλ€.
κ°μ¬μ κΈ
μ΄ μ±κ³Όλ μ λΆ(κ³ΌνκΈ°μ μ 보ν΅μ λΆ)μ μ¬μμΌλ‘ νκ΅μ°κ΅¬μ¬λ¨μ μ§μμ λ°μ μνλ μ°κ΅¬μ(No. RS-2023-00220019).
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