Sustainable Concrete
Sustainable Concrete Products
Because of its durability concrete will not rust, rot or burn and it requires less energy and resources over time to maintain, repair or replace. Structures built with concrete have optimal energy performance, incur little waste and it can be readily recycled.
From a material standpoint, Cemstone is a leader in the use of locally sourced aggregates and supplemental cementitious materials such as fly ash, ground granulated blast furnace slag and silica fume. These materials help reduce carbon dioxide emissions as well as make concrete stronger, more durable and more resistant to the elements of nature. Product availability varies by location.
Cemstone offers a variety of sustainable concrete options and practices to consider for your next project.
Portland Limestone Cement
Portland-limestone cement (PLC) is a blended cement with a higher limestone content, which results in a product that works the same, measures the same, and performs the same, but with a reduction in carbon footprint of 10% on average. PLC manufacturers have developed a modified formulation of their most important product to respond to growing calls for reducing embodied carbon associated with construction.
Why do we use PLCs?
Portland-limestone cement (PLC) is a blended cement with a higher limestone content. It results in a product that works the same, measures the same, and performs the same, but with a reduction in carbon footprint of 10% on average.
Sustainability encompasses many aspects designed to improve construction practices, including more efficient use of natural resources, better thermal performance of structures, and reduced environmental impacts, with a focus on embodied carbon. One area of growing concern to environmental leaders is CO2 emissions. Like all building materials, portland cement has an environmental footprint, and it is often described in terms of greenhouse gas equivalents. Cement is made by grinding clinker—the main energy intensive ingredient—to a fine powder. Producers know that replacing some of the clinker in portland cement with ground limestone offers benefits, the most important being that it reduces the embodied CO2 of the cement.
Environmental Product Declaration
Cemstone is proud to have participated in the National Ready Mixed Concrete Associations (NRMCA) industry-wide Environmental Product Declaration (EPD) Program.
An Environmental Product Declaration (EPD) is defined by International Organization for Standardization (ISO) 14025 as a Type III declaration that “quantifies environmental information on the life cycle of a product to enable comparisons between products fulfilling the same function. The EPD methodology is based on the Life Cycle Assessment (LCA) tool that follows ISO series 14040. EPDs are primarily intended to facilitate business-to-business transactions, although they may also be of benefit to consumers who are environmentally focused when choosing goods or services. Cemstone has implemented EPDs in order to improve our sustainability goals and to demonstrate a commitment to the environment to customers.
To date, Cemstone has developed EPDs for 20 of our manufacturing facilities in accordance with strict international standards that include a transparent verification process for adopting Product Category Rules by which EPDs are developed and verified. Working with the NRMCA, Cemstone has performed comprehensive Life Cycle Assessments on our concrete from these 20 facilities and reported the results in the industry-wide EPD.
“If all cement used in the U.S. in 2019 had been converted to PLC, it would have reduced CO2 emissions by 8.1 million metric tons, which the U.S. EPA says is the equivalent of taking 1.75 million cars off the road for an entire year.”
The Portland Cement Association
Supplementary Cementing Materials
By using materials that “do more with less”, valuable resources are conserved. For example, by increasing the use of fly ash (an industrial byproduct) in place of cement, material is re-used while the carbon dioxide emissions from cement manufacturing are reduced. Supplementary cementing materials (SCMs) contribute to the properties of hardened concrete through hydraulic or pozzolanic activity.
Typical examples of SCMs are fly ashes, slag cement (ground, granulated blast-furnace slag), and silica fume. These can be used individually with portland or blended cement, or in different combinations. SCMs are often added to concrete to make concrete mixtures more economical, reduce permeability, increase strength, or influence other concrete properties.
What is fly ash?
Fly Ash is the most used pozzolan in concrete, is a by-product of thermal power generating stations. Commercially available fly ash is a finely divided residue that results from the combustion of pulverized coal and is carried from the combustion chamber of the furnace by exhaust gases.
What is slag?
Slag Cement, formerly referred to as ground, granulated blast-furnace slag, is a glassy, granular material. It is formed when molten, iron blast-furnace slag is rapidly chilled – typically by water sprays or immersion in water – and subsequently ground to cement fineness. Slag cement is hydraulic and can be added to cement as an SCM.
Pervious concrete
Pervious concrete is an effective way to control storm water runoff by creating a storage area below the pavement surface. When properly designed and installed, pervious concrete can be used for sidewalks, parking areas and even city streets. Even in northern climates, the use of pervious concrete has been shown to be an effective storm water management system. Some sustainable benefits of pervious concrete include:
Improved water quality. The porous structure of pervious concrete allows stormwater to pass into underlying soils and filters out harmful sediments.
Reduce and refresh. Pervious concrete lessens the heat island effect, recharges aquifers and eliminates the need for storm water retention ponds all while maximizing the land that can be developed and lowering construction costs.
Protection. When placed near trees and other foliage, pervious concrete protects the root structure of them.
Reinforcement. Pervious concrete can also be used for reinforcing sand traps at golf courses. Oftentimes, intense rainfall events can cause underlying soils within bunkers to erode and wash away. When placed beneath the bunker sand, pervious concrete will act as a base material that provides stability, while maintaining adequate drainage.
Cemstone is a pioneer in the development and testing of pervious concrete in the upper Midwest. Contact us to learn more about pervious concrete and its many applications.