Cement is the world’s most prevalent manmade material, with approximately 0.56 tonnes produced annually for every person on Earth. It binds concrete, which is used to construct much of the built environment—including homes, schools, offices, roads, runways, tunnels, and bridges.
Industrial production accounts for around 21% of all greenhouse gas emissions attributed to human activity (IPCC 2014). Of this, nearly a quarter, or 5% of global emissions, comes from cement production (WBCSD CSI)—making the industry among the largest contributors to climate change. Of the cement industry’s emissions, around 50% can be attributed to the calcification process itself, 40% to fuel used in heating the kiln, and the remaining 10% for grinding and transport (WBCSD CSI).
Because the cement industry has historically been a major contributor to greenhouse gas emissions, there is an opportunity today to significantly reduce emissions through efficiencies and innovations within the sector. The use of technology, sensors, data analytics, and automated inputs will not only save customers’ time and money, but it will also significantly reduce their carbon footprint.
GCP Applied Technologies has created VERIFI, a system of sensors and devices managing 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 job site. Finally, using connected device and 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. Using advanced data tools 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 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% 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, the software tools can reduce the overdesign needed to consistently meet a given performance specification.
- Waste reduction. NRMCA estimates 5% of ready-mix concrete deliveries in the U.S. are rejected at the job site, 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 the 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% to 3.8% – saving time, money, and materials. Since a typical concrete load represents 5,500 lbs 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% 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, realtime data 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%, 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 these software tools have less need to climb a ladder next to a spinning drum—a clear and important safety benefit.
With this new category-creating technology, concrete production can shift from an inexact and manual process to a precise and automated one. With that shift comes the ability to provide consistent quality concrete while saving time, money, materials and energy. Not only does this benefit our customers, it also benefits our society and our planet.
A number of stakeholder groups, beyond GCP’s direct customers, have an interest in the social and environmental benefits. For example:
- Architects are often enthusiastic about green design and sustainability. Through our new and growing Design Advantage service, GCP is interacting more frequently and collaborating more closely with architects in the North American market, and is communicating in a more integrated way about Specialty Building Materials and Specialty Construction Chemicals products. This is an excellent opportunity to highlight the advantages of our new process-management technologies, including their substantial environmental benefits.
- Municipal leaders (including mayors, departments of transportation, and purchasing agents) are another important constituency. Many are leading climate change initiatives of their own, and may be able to encourage adoption of the technology—either through government purchasing or building codes – as part of their broader efforts to reduce greenhouse gas emissions.
- Environmental advocates around the world, including the CDP (formerly known as the Carbon Disclosure Project), the World Business Council for Sustainable Development (which has a Cement Sustainability Initiative), the United Nations Environmental Program, the Massachusetts Institute of Technology (which has a Concrete Sustainability Hub), and many others. These organizations may be willing, or even eager, to support GCP’s efforts with their own time, energy, resources and reputations—if we can identify opportunities to collaborate.
Examples and Data
Example One: During 2013-2016, eight customers using VERIFI technology showed a 10% 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. And at the prevailing price of $3/gallon, it saved about $1,350,000 in fuel costs. Because these customers represented only about 1% 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.