Early Age Concrete Strength Monitoring Using Power Spectral Density and Wavelet Packet Analysis

Figure 8

The power spectral density: (a) 1 d, (b) 3 d, (c) 5 d, (d) 7 d, (e) 9 d, (f) 11 d, (g) 13 d, (h) 16 d, (i) 19 d, (j) 22 d, (k) 25 d, and (l) 28 d.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)

(l)