The Future of Cement for Water Resource Application

Location:  Grand Ballroom B

Speaker:  Josh Gilman, P.E. – Portland Cement Association (PCA)

Presentation Description
Concrete pipe and other products contribute to the economic viability and resilience of water resources projects. Products are often selected for the long service life they provide, which can be readily demonstrated with a life cycle analysis (LCA). The initial carbon footprint of any material or construction method is an important aspect of an LCA, but it is not the only one and may not even have the greatest contribution: maintenance considerations and overall service life may ultimately outweigh the initial footprint. Long lasting, sustainable structures require durable and resilient materials, and for most applications concrete is the material of choice.

Ordinary portland cement (OPC) manufactured to meet the ASTM C150 standard has been the default binder material in concrete specifications for water resources projects for decades. The properties and performance of both fresh and hardened OPC concrete are well documented, as is the superior durability and longevity of concrete structures that are properly designed and constructed. The environmental impact of manufacturing OPC is also well documented, and regulators impose strict requirements on all cement producers to monitor and report emissions. According to the U.S. Environmental Protections Agency (EPA), the CO2 footprint of cement production in the U.S. accounts for 1.25% of the total U.S. CO2 emissions. Although the industry has made considerable progress since the 1970’s to reduce its energy demand by 40%, the Portland Cement Association (PCA) and its members recognized that more must be done to tackle the carbon footprint of the cement and concrete industry, and developed a Roadmap to Carbon Neutrality to lay out specific tasks and targets to achieve its goals.

Portland-Limestone Cement (PLC), was developed with the capability to replace Type I/II OPC in concrete mixtures at a 1:1 ratio. PLC is engineered to maintain the same performance as OPC but as a “greener” cement, offers up to a 10% lower carbon footprint than OPC. PLC is manufactured to meet the ASTM C595 blended cement specification, and extensive comparison testing has demonstrated its equivalent properties and performance, including alkali-silica reaction (ASR) resistance, corrosion prevention, freeze-thaw resistance and sulfate resistance when compared to OPC. PLC performs like OPC when combined with supplementary cementitious materials (SCMs) and admixtures in concrete mixtures at equivalent proportions. Replacing OPC with PLC in concrete for water resource projects delivers the same long-term durability and resilience with the added benefit of significantly reducing the carbon footprint.

Learning Objectives:
• Describe the importance of evaluating the whole lifespan of a project to understand the carbon footprint and compare alternatives.
• Explain the environmental impact of producing portland cement and the efforts of the industry to reduce its carbon footprint.
• Recognize PLC and how it can be substituted for OPC to improve the environmental impacts of concrete while maintaining the same properties and performance.

Speaker Bio

Joshua Gilman, P.E., is the manager of water resources and geotechnical markets for PCA. He is responsible for market development and expanding the use of concrete and other cement-based materials for water resources and geotechnical applications including roller-compacted concrete, soil-cement and waste stabilization.

Gilman has more than 10 years of experience in the geotechnical and water resources markets. Prior to joining PCA, Gilman held geotechnical engineering positions with consulting firms in the Northeastern and Southeastern United States, and most-recently managed a satellite office for a large firm performing geotechnical and construction materials testing services. Water resources, especially dam engineering and dam safety, have been a focus throughout Gilman’s career including employment with a multi-discipline consulting firm that served the hydropower industry.

Gilman holds a Bachelor of Science degree in Civil Engineering from Norwich University, and is a licensed professional engineer in the state of North Carolina.