The cement industry has historically been a major contributor to greenhouse gas emissions, but there is an opportunity today to significantly reduce emissions through efficiencies and innovations within the sector. GCP Applied Technologies can play an important role through its leadership in the use of connected devices. Its patented VERIFI® technology uses sensors, data analytics, and automated inputs to not only save customers time and money, but also to significantly reduce their carbon footprint.
HOW THE TECHNOLOGY WORKS
VERIFI is a system of sensors and devices that manage the flow rate (slump) of a concrete shipment from the ready-mix plant to the jobsite. While in transit, the system performs several key functions. It controls concrete mixing, using only the necessary number of drum rotations and harnessing excess energy from the truck’s engine whenever possible. It also measures the flow rate of the concrete, and can provide precise injections of water and admixtures to achieve the specified slump upon arrival at the jobsite. Finally, VERIFI software tracks the movement of the truck along its route, identifying opportunities for improved fleet efficiency.
Together, these functions significantly reduce the time it takes to deliver concrete, allowing more product to be delivered with the same number of trucks and drivers. VERIFI also conserves materials by delivering concrete that consistently meets specifications, thereby avoiding rejected loads. Consistent quality allows for more efficient mix designs (i.e., with lower cement content and/or higher supplementary cementitious material content). These efficient mix designs can radically reduce cement use, leading to further cost savings and environmental benefits.
The environmental benefits of the VERIFI technology can be thought of in three categories:
- Cement reduction: Various stakeholders in the production of concrete often add water to achieve the specified slump, but this can weaken the concrete—in some cases leading to concrete placement that eventually fails testing and must be torn out. To avoid such costly scenarios, concrete mixes are routinely “overdesigned” to include more cement than truly needed, in order to compensate for the addition of water. A conservative estimate is that 5 percent of the cement included in the design of a concrete mix is included only to hedge against these issues. Through precise and reliable quality control, VERIFI can reduce the overdesign needed to consistently meet a given performance specification.
- Waste reduction: NRMCA estimates 5 percent of ready-mix concrete deliveries in the U.S. are rejected at the jobsite, typically because they fail to meet the specified slump at the time of delivery. The returned concrete is either crushed and used as road base, made into blocks, or simply discarded. All these scenarios require additional time, fuel use, and a duplication of the load of concrete. Because VERIFI software monitors concrete consistency in transit, and controls precise injections of water or admixtures en route, the concrete is delivered more consistently within performance specifications. Early data indicates that this could reduce rejection rates from 5 percent to 3.8 percent—saving time, money, and materials. Since a typical concrete load represents 5,500 pounds of carbon dioxide emissions, reducing concrete waste also benefits the environment.
- Fuel efficiency: In ready-mix concrete delivery, fuel use is a significant source of cost and environmental impact. Approximately 23 percent of fuel in a concrete delivery is used for high-speed drum rotations that mix the concrete. The timing of these rotations is typically controlled by the truck driver—based on minimal information about concrete consistency or fuel efficiency. In contrast, VERIFI software gives the driver instructions on the optimal number and timing of rotations. Early data suggests that the number of high speed revolutions can be reduced by 10 percent, representing significant cost reductions and associated environmental benefits.
The advantages described above reduce cost, maintain critical performance specifications, and significantly improve environmental performance. In addition, truck drivers using VERIFI software have less need to climb a ladder next to a spinning drum— a clear and important safety benefit.
EXAMPLES AND DATA
Example One: During 2013–2016, eight customers using VERIFI technology showed a 10 percent reduction in the energy used for drum rotation, compared with pre-VERIFI technology estimates based on the 2015 NRMCA survey. This represented 450,000 gallons of fuel savings, or about 4,000 metric tons of avoided CO2 emissions—equal to taking 856 passenger vehicles off the road, according to the EPA. And, at the prevailing price of $3/gallon, it saved about $1,350,000 in fuel costs. Because these customers represented only about 1 percent of the U.S. ready-mix market (and a much smaller share of the global market), the potential impact through widespread adoption is much larger.
Example Two: An average of 2,044 pounds of CO2 are emitted for every metric ton of Portland cement produced in the U.S. Using VERIFI technology, a single customer was able to optimize two widely-used mix designs, reducing cement use by 2,722 metric tons in 2016 alone—the CO2 equivalent of taking 583 passenger vehicles off the road for a year—and providing a significant cost savings to the producer.
- Fuel efficiency: With an average number of high speed revolutions of 200 per load, early results indicate VERIFI technology can reduce high speed revolutions by 10 percent—this reduction results in an estimated 3 liters of fuel saved per load.
- Concrete waste reduction: With 350 million cubic yards of concrete produced in North America each year, a rejection rate of 5 percent means that 17.5 million cubic yards are rejected annually—at a cost of around $175 million. Early results indicate that VERIFI can reduce rejection rates roughly 1.2 percentage points.
- Eco-efficient mix design: An average mix design contains roughly 550 pounds of cement; if a conservative estimate of overdesign is 5 percent, that would be 25 pounds of cement per cubic yard—or 250 pounds per truckload.
About the author:
Matthew Nazarenko is the global marketing manager for the Verifi® technology platform at GCP Applied Technologies. Matt is responsible for the development and execution of the global Verifi business expansion program. He leads the multi-generation product development process, working with a cross-functional team and closely collaborating with customers. For more information, visit www.gcpat.com.
Modern Contractor Solutions, May 2018
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