This view “inside” the “H” shows the beam’s smooth surface. Cor-Tuf hardens within two to three hours and can be handled in eight hours following a pour. Half-strength is produced in five to seven days; full curing is obtained in 28 days. Additional strength can be achieved with increased temperature, steam, or both during curing.
What makes a good building material? In our opinion, it must be strong and durable; light, with minimum design constraints; easily installed and compatible with common techniques; and long-lasting, created from the start to protect against damage.