COMMAND Alkon says its has all the right tools to ensure that self-consolidating concrete (SCC) is consistently produced to the best quality possible.

“SCC provides improved product quality at reduced costs,” says a spokesman for the US-headquartered firm. “However, like most production enhancements, improvements do not occur without some investment. Many producers have discovered that producing SCC is not very easy. Factors related to mix design proportions, aggregate gradations, and moisture control, require tight product specifications if consistent quality SCC is to be achieved. A challenge for control system innovators is to accommodate these requirements without increasing cost to the producer.”

 Command Alkon, he continues, invested many years and much effort into understanding the requirements of SCC. “These efforts have culminated in the introduction of new technologies that offer producers significant improvements in SCC consistency, batch-to-batch, based on the use of Hydronix mixer moisture probe technology to control total water in the mix.”

The first consideration for consistent SCC is to assure a consistent yield of raw materials. Command Alkon’s new approach ensures consistent aggregate material yields by measuring the bin moisture as the material flows across the gate during weigh up and correcting the required weight in real time. This process delivers the exact material amount as specified in the mix design.

“In addition, Command Alkon measures all of the moisture content in the mixer before cement, admixtures, or water is added,” he says.  “By measuring all of the “dry” aggregate moisture once in the mixer, the process accounts for any rinse water left from the last batch or any other foreign sources of water. Examples of foreign water introduction are rain water on a material transfer belt during mixer charge or ice in the material bin that has not melted. Often small amounts of ice will melt during the aggressive dry mixing action of which Command Alkon can measure this total water. With the knowledge of total water, producers are, for the first time, able to produce consistent SCC spreads.”

High absorption aggregates can also be accommodated by measuring the moisture content in the mixer.

“Consider a producer that, at one location, had a high absorption aggregate. The producer proposed sprinkling the aggregate with water; hoping that the water sprinkling would produce an aggregate at saturated surface dry (SSD) conditions. However, there was no way to ensure that the aggregate was at the SSD moisture. Command Alkon’s solution was to introduce a small amount of water during the dry aggregate mixing cycle assuring that the SSD aggregate was always being measured,” he explains.

Another important improvement provided by the company’s new toolset is the ability to specify a mix calibration based on the volume of dry aggregate in the mixer. Each mix size is calibrated for moisture content and this same calibration is used for the mixer dry aggregate moisture measurement. The mixer volume calibration is a function of the sensor physics. Without a mix calibration based on mixer dry aggregate volume, errors in the moisture measurement are introduced.

Additional tools provided by Command Alkon for the SCC production include the ability to graph and store the mix moisture information with the batch weights. The graph produced during batching of the concrete has proven to be an invaluable tool for QC analysis of the concrete quality. The tools allow producers to monitor moisture, temperature, air content, wattage draw, and any number of other relevant sensors and plot them in real time with the batch results. All of this data is included with the final batch report for storage.

Meanwhile, Command Alkon continues to develop and enhance its suite of products for other facets of the industry including ready-mixed plant automation, ready-mixed dispatching, dispatch optimisation, quality control, bulk materials distribution, business intelligence, back office operations, electronic content management, voice-based scheduling, and now mobile computing.

For ready-mixed plant automation, Command Alkon offers COMMANDbatch, a suite of tightly integrated applications that allow the operator to focus on the delivery of quality concrete and rely on the suite to manage the details. “Applications such as precision water system ensure total water management and load consistency, precision temperature system ensures that the concrete placed in the truck is at the right temperature, while plant watcher electronically monitors all activity to flag an out-of-tolerance load before it leaves the yard or to alert maintenance personnel to potential problems that could affect production,” the spokesman says.

Meanwhile, COMMANDconcrete, a state-of-the-art ready-mixed concrete dispatching solution, assists producers with increasing dispatch efficiency, improving truck utilisation, reducing delivery costs, and providing timely and accurate operational information to enhance decision making. “It offers order entry, dynamic scheduling, ticketing, truck tracking, reporting, and a broad and in-depth set of features. It seamlessly integrates with the back office, quotation, batching, and/or signalling systems to provide a consistent flow of information and business operations across the enterprise,” says the spokesman.

Another product is the COMMANDqc, a full-featured quality control, mix management, and production monitoring system.

“This provides easy access to all the information you need for formulating mix designs, allows you to collect, organise and analyse production results and test data, and enables you to be proactive in reducing production variations, maximising product performance, and minimising materials costs,” says the spokesman.

Finally, Apex meets the operational and management demands of the bulk materials distribution business including ticketing, loadout, rail,vehicle/order dispatch,truck tracking, inventory, production/operations, invoicing, receivables and quotation.