Issue 44

B. Rahmanzadeh et alii, Frattura ed Integrità Strutturale, 44 (2018) 16-24; DOI: 10.3221/IGF-ESIS.44.02 22 Tab. 4 shows the values of hydraulic conductivity coefficient and porosity of concrete in terms of water-cement ratio. The values of Tab. 5 are required for obtaining the hydraulic conductivity coefficient and porosity of Nano silica concrete. W/C Hydraulic Conductivity Coefficient of Cement (m/s) Porosity of Concrete 0.3 1.7 ⤬ 10 -15 13.1% 0.34 3.84 ⤬ 10 -15 15.2% 0.38 8.25 ⤬ 10 -15 19.37% 0.42 13.95 ⤬ 10 -15 21.56% 0.46 28.5 ⤬ 10 -15 25% Table 4 : Hydraulic conductivity coefficient and porosity of concrete in terms of water-cement ratio. Permeability time (s) Height Arising from Water Pressure (m) Cement Specific Weight (g/cm) Cement Degree of Hydration (%) 259200 82 3.15 80 Table 5 : Required values for calculating hydraulic conductivity coefficient and porosity of concrete. C OMPRESSIVE S TRENGTH ompressive strength tests on cube samples of 150 × 150 × 150 mm at the age of 7, 28 and 91 days have been done with a pressure test device with a capacity of 2000 kN (TEKNO test-Italy) at a speed of 2.5 kN/s accordance to ACI-C330 standard. The value of Compressive strength of samples can be evaluated using Eq. 5 as following as: Compressive Strength =    P A / 1000 (4) Fig. 8 is the illustration of compressive strength test machine. Figure 8 : Compressive strength test machine C