Fig 1.
The grain size of cement.
Table 1.
Composition of cement.
Table 2.
Mixture ratio.
Fig 2.
(a) Plug molding; (b) Samples after curing.
Fig 3.
PC samples in the wet state.
Fig 4.
Uniaxial compression test of PC.
Fig 5.
Ultrasonic velocity acquisition by MC-6320 non-metal ultrasonic detector.
Fig 6.
Apparent change of corroded PC.
Fig 7.
Evolution of compressive strength, (a) 3% Na2SO4; (b) 5% Na2SO4; (c) 8% Na2SO4.
Fig 8.
Reduction ratio of compressive strength after 140 days of corrosion.
Fig 9.
Ultrasonic velocity evolution of PC samples, (a) w/cratio = 0.28; (b) w/c ratio = 0.31; (c) w/c ratio = 0.34.
Fig 10.
Connection among both PC strength fc(t) with ultrasonic wave speed C(t), (a) w/c ratio = 0.28; (b) w/c ratio = 0.31; (c) w/c ratio = 0.34.