Below is an excerpt from a national publication describing CP&P’s new batch plant at Jessup…
In February, Concrete Pipe & Precast, LLC, based in Ashland, Virginia, USA, fired up a new, automated batching system at its Jessup, Maryland, plant. The 70,000 square foot production facility experienced an equipment failure in its aging batch plant last October.
Pipe production systems at Jessup include the Hawkeye Pedershaab PipePlusPlus, PipePro XT, Single Station Model 144 VUP large pipe system, and ROCO and VROC automated product and ring handling systems. Prior to October 2014, the plant relied on two horizontal ribbon mixers located at the base of a 110-foot tall batching tower.
The original batching system relied on gravity to batch mix components down to the mixers. The height of the batching structure made it difficult to maintain the system and the manual nature of the operation made it highly labor intensive.
While the Jessup plant relied on a proven mix design, the battle to get the water/cement ratio just right, combined with manual batch operation, led to under yielding and high cement usage, which frequently resulted in quality problems.
Focus on commitment
Of course, no company ever wants to experience a major equipment breakdown, but in the case of the Jessup plant, this came at an “opportune” moment of sorts. CP&P, the product of a joint venture and multiple acquisitions, was just about to launch a company-wide quality improvement and identity building program—“Commitment 2016”.
A key focus of the new program is to provide customers with “relentless platinum grade quality” in products and services. The Commitment 2016 program roll-out started in January at all 13 CP&P plants. The firm’s Commitment 2016 committee provides ongoing guidance and direction to help each plant to develop and implement processes and practices that will ensure platinum grade quality.
The selection of a new batching system for the Jessup plant took on new importance in light of the Commitment 2016 program. The selection team considered several proposals from leading batch system providers.
Back in action
“It’s like night and day,” Blankenship notes. “Our old batching system required constant attention and adjustment on every batch. The new ACT/Wiggert system almost runs itself. We have one operator for the entire batching system. We’ve seen a 20 percent reduction in man hours per ton through reduced overtime and other labor efficiency savings.”
The old batching system at the Jessup plant was not able to store any batch records. Unless the operator remembered to print out a ticket for each batch, there was no record of the batch. The ACT PCS controls electronically records the details of every batch and tracks material inventory, providing reminders when bins or silos begin to run low.
Moisture control is also automatic. “We went ahead and put moisture probes in every aggregate bin so we know exactly how much water we’re getting with the aggregates. That gives us the proper yield every time and the water/cement ratio is always spot on. The probe in the mixer precisely maintains correct water/cement ratio.”
Improved moisture control has led to near-perfect mix consistency. “It used to be we’d hit our mark about 90 percent of the time and have to manually adjust the moisture to correct any errors,” Blankenship continues. “Now, we’re hitting the mark nearly 100 percent of the time, and that consistency is reflected in our quality and product appearance.
Now that batching consistency and accuracy is improved, the Jessup production team has been able to produce mix designs exactly as specified. “The biggest benefit is consistency and reliability in batching,” Blankenship notes. “We can very easily adjust batch sizes to match what we’re making at any given moment. That way we get the freshest concrete just-in-time. On the PipePro, we’re running 1.5 yards per batch and on the PipePlusPlus it’s 1.75 or 2 yards depending on what we are running.”
Uninterrupted batching has resulted in a reduction in production machine wait time from more than an hour per day to less than five minutes. The Jessup plant is able to achieve its target compressive strength of 4,000 to 6,000 lbs per square inch with less cement thanks to the high shear mixing action of its ACT/Wiggert mixers and the accuracy of its PCS computer control system.
“The biggest benefit with our new batch plant is product quality improvement,” he emphasizes. “The consistency of the concrete we produce is so much better than before, the resulting quality is reflected in every aspect of our operation. We get consistent, accurate batches all day long with no interruptions—it’s great!”