Evaluation Evaluation Evaluation Evaluation of of of Pouring of Pouring Pouring Pouring Capacity Capacity Capacity Capacity for for for for Paved Paved Paved Paved Track Track Track Track Mortar Mortar Mortar Mortar using
using using
using the the the Impact the Impact Impact Echo Impact Echo Echo Echo method method method method
The paved track is a kind of pre-packed concrete in which mortar is poured to the void of the ballast. The pouring capacity is the most important for the strength of the paved track. The developed pouring material has the 6～8sec mobility and used minute particles aggregate.
However, they has a rapid hardness speed, the pouring ability can be fallen. So, the impact echo method was applied to estimate the pouring ability of the paved track in this research. The impact-echo method is a technique for flaw detection in concrete. It is based on monitoring the surface motion resulting from a short-duration mechanical impact. The method overcomes many of the barriers associated with flaw detection in concrete based on elastic wave methods. In this paper, we make an attempt to estimate the dynamic stiffness, thickness of the layer, existence and location of inside flaw of paved track taking advantage of this technique.
Impact displacement
transducer, geophone, or accelerometer
4 3 2 1 0 -1 -2 -3
Amplitude
10x10 -3 8 6 4 2 0
time, sec 1.4x10 -3
1.2 1.0 0.8 0.6 0.4 0.2 0.0
Magnitude
6000 5000 4000 3000 2000 1000 0
Frequency, Hz
Waveform
Spectrum
∆t=0.333 msec
3120 Hz
16cm
30cm No.10 No.9 No.8 No.7 No.5 No.6
No.4 No.3 No.2 No.1
80x10-6
60
40
20
0
Amplitude
25x103 20 15 10 5 0
Freq, Hz No.1 Thickness = 17cm R.Freq = 9984 Hz
400x10-6
300
200
100
0
Amplitude
25x103 20 15 10 5 0
Freq, Hz No.9 Thickness = 28cm R.Freq = 6016 Hz
6000 5000 4000 3000 2000 1000
Vp (m/sec)
28 26 24 22 20 18
Thickness (cm)
0 2 4 6 8 10
10 15 20 25 30 35 40
Thickenss(cm)
Loc ation nu m ber R e a l th ick n e s s(c m ) C a lc u la te d th ick n e s s(cm )
8 88 8 2
22 2 1 11 1 3333
4 4 4 4 6666
5 55 5 7777 9999
10 10 10 10 12121212
11 11 11 11 13131313
14 14 14 14 16161616
15 1515 15 17171717
18 18 18 18 20202020
19 19 19 19 21212121
22 2222 22
60x10-6 50 40 30 20 10 0
Amplitude
25x103 20 15 10 5 0
Freqency, Hz(Power Sp) 8000
6000
4000
2000
0
FreqRes
20 15 10 5
Site No
충진면 침목면
35x10-6 30 25 20 15 10 5 0
Amplitude
25x103 20 15 10 5 0
Freqency, Hz(Power Sp)
100x10-6 80 60 40 20 0
Amplitude
25x103 20 15 10 5 0
Freqency, Hz(Power Sp)
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0
No.1 No.2 No.5 No.6 No.9 No.13 No.14 No.18 No.21 No.2-1
코어 시험편
압축강도(MPa)
