Shotcrete is a precise mixture of graded sand, aggregate and cement that we call the “mix design”.
The sand is often mined or manufactured (we use only virgin sand, no manufacured). The quality of the sand is critical in shotcrete and allows for longer pushes and higher pressures if correct.
The aggregates we use are generally 1/2″ or smaller and include a lot of buckshot and fines down to #10 or less.
The cement is Portland type I/II provided locally from Ashgrove out of Durkee, Oregon. Shotcreter’s only uses American Made Portland Cements.
The ratios we have determined through the years is roughly 25% agg and 75% sand and over 800 lbs. of cement along with some admixes.
The admixes that make shotcrete a reliable component for the installers and crew are critical.
Shotcreter’s has on hand high-end super plasticizers, air entrainments, water reducers and pumping aids.