Concrete contractor Dan Ahrens is sold on the machine that helped his crews easily place and finish 20,000 square feet of exceptionally flat concrete floor in one day. The self-propelled screeding machine strikes off concrete to the correct grade quickly and without intermediate forms or screed rails. The machine is a four-wheel-drive vehicle with two-axle steering. A telescoping boom supports the vibrating screed and an auger that uniformly distributes concrete in front of the screed. Laser receivers control grade for the concrete surface through hydraulic masts that raise or lower the auger and screed. The receivers check and adjust screed elevation five times every second.
The short setup time, easy strikeoff, and fast finishing are factors that contribute to the high production rates. No intermediate forms are needed for pours from 88 to 112 feet wide, therefore carpenters are able to finish edge forming quickly. Strikeoff is done as quickly as the concrete can be placed. Also, the laser-guided screed allowed the concrete to be placed in wide strips, thus speeding the work by saving time on forming. To check for flatness, the floors were measured with a profiling device the day after they were poured. Posting the results on a jobsite bulletin board was a key factor in controlling flatness because it involved all the workers as well as supervisors.