Producers have saved money because self-consolidating concrete (SCC) requires less consolidation and quicker form-strip intervals. Using the material also leaves better surface textures. So what is the next improvement precast producers using SCC can bring to their operations?

Ever resourceful, some producers are looking to become even more efficient. They are economizing operations based on maturity measurement. Implementing this science has been easy. Several maturity measuring systems have been widely used.

The ZoneCure maturity system has been used successfully in field construction. It employs wireless technology to monitor concrete's maturity. The system, developed by Con-Cure Corp., of Ballwin, Mo., has been used extensively on construction projects around North America, including post-tensioning, tilt-up, and foundation form removal projects. Now precast producers are using the technology to become more productive.

Maturity measuring devices are not new. They are accurate methods to monitor concrete quality and performance. These procedures are outlined in documents prepared by ACI Committee 235, Material Science. In many operations, engineers have used maturity measuring systems to significantly reduce using compressive test cylinders.

But what's new about ZoneCure is that it delivers a total wireless, system solution to field maturity measurement for less than $15,000. The system does not require hand-held recorders or any plant wiring to transmit the probes' readings. For precast producers that have acres of live inventory undergoing final curing, the system simplifies collecting test samples.

Mesh network

ZoneCure uses a mesh networking technology. Each maturity meter transmits its information to a nearby maturity meter that in turn passes the signal on to the unit located near the transmitter. Meters must be within 200 feet of the neighboring meter. The last meter in the chain can be up to 40 miles from the receiving computer. Each meter has its own wave length that is embedded in the wireless transmission to the quality control station.

A ZoneCure computer collects and records all received transmitted data. Using a proprietary program, the software automatically displays the current temperature of the element in which the reusable probe is embedded and the ambient temperature of the work area. Using a custom-developed predictive maturity code for each mix design, the software predicts strength.

One precast producer reported a three-month payback on his investment with the system, says John Gnaedinger, ZoneCure's development engineer. Most of the improvement came from the ability to economize mix designs using the system's predictive maturity calculations. “The producer was able to balance bed time to cement use more efficiently,” says Gnaedinger.

Another producer plans to use Zone-Cure to help solve plant congestion and to create a just-in-time shipping process. The producer will place a cast element in his curing area only long enough to have it achieve 80% of its targeted strength as measured by the ZoneCure probe.

Workers will then wrap the element with a curing blanket and place it in an outdoor storage area. When the remote maturity sensors signal full strength, the producer will remove the probe and blanket for shipping. The producer will save by using less material, increasing casting floor utilization, and lowering curing costs.

To learn more, visit www.con-cure.com.