(a)
(b)
(c)
(d)
Figure 4: Hardened properties of RM, M1, M2, and M3 concretes (W/C = 0.40, s/a = 0.40, and C = 340 kg/m3) at the age of 28 days: (a) compressive strength, (b) Young's modulus, (c) splitting tensile strength, and (d) ultrasonic pulse velocity.