Portland cement
noun
Port·land cement
ˈpȯrt-lən(d)- 
variants
or less commonly portland cement
: a cement (see cement entry 1 sense 1b) that sets under water and that is made by finely pulverizing the clinker produced by heating a mixture of clay and limestone or similar materials to a high temperature just short of fusing
Drexel engineers have found a way to improve upon ordinary Portland cement …, the glue that's bonded much of the world's construction since the late 1800s.—
Swiss National Science Foundation
Swiss National Science FoundationOnce the joints are open, refill them with a dry mix of stone dust and portland cement, mixed at a ratio of 1 part cement to 6 parts dust.—This Old House
This Old HouseExamples of Portland cement in a Sentence
Recent Examples on the Web
That’s what’s interesting about a new paper published last week, which describes not a new formula for cement, but rather a less carbon-intensive process for making Portland cement, the most common type used.
—Alex Knapp, Forbes.com, 18 May 2026
Iron, magnesium, and aluminum could also be separated and recovered, and leftover silicate material can serve as the additive for Portland cement instead of something like coal ash.
—Scott K. Johnson, ArsTechnica, 15 May 2026
Still, the transition may face resistance because the cement industry is heavily optimized around limestone and Portland cement standards developed over more than a century.
—Neetika Walter, Interesting Engineering, 14 May 2026
Portland cement, the key component of concrete, is responsible for about 8% of global greenhouse gas emissions.
—Alcina Johnson Sudagar, The Conversation, 12 Feb. 2026
Green concrete Manufacturing Portland cement, the key binding ingredient in concrete, currently contributes around 8% of global CO2 emissions.
—The Week Uk, TheWeek, 30 Dec. 2025
By establishing manufacturing operations in regions like Pakistan, where resources such as gypsum and Portland cement are readily available, West Cal has engaged in international trade with a focus on ethical collaboration.
—Connie Etemadi, USA Today, 14 Oct. 2025
But by the early 20th century, Portland cement had overtaken lime as the preferred building material.
—Adrienne Davis, jsonline.com, 11 Sep. 2025
This involved a mix of Portland cement, fine sand, and silica fume.
—New Atlas, 10 July 2025
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Alex Knapp, Forbes.com, 18 May 2026
Iron, magnesium, and aluminum could also be separated and recovered, and leftover silicate material can serve as the additive for Portland cement instead of something like coal ash.
—Scott K. Johnson, ArsTechnica, 15 May 2026
Still, the transition may face resistance because the cement industry is heavily optimized around limestone and Portland cement standards developed over more than a century.
—Neetika Walter, Interesting Engineering, 14 May 2026
Portland cement, the key component of concrete, is responsible for about 8% of global greenhouse gas emissions.
—Alcina Johnson Sudagar, The Conversation, 12 Feb. 2026
Green concrete Manufacturing Portland cement, the key binding ingredient in concrete, currently contributes around 8% of global CO2 emissions.
—The Week Uk, TheWeek, 30 Dec. 2025
By establishing manufacturing operations in regions like Pakistan, where resources such as gypsum and Portland cement are readily available, West Cal has engaged in international trade with a focus on ethical collaboration.
—Connie Etemadi, USA Today, 14 Oct. 2025
But by the early 20th century, Portland cement had overtaken lime as the preferred building material.
—Adrienne Davis, jsonline.com, 11 Sep. 2025
This involved a mix of Portland cement, fine sand, and silica fume.
—New Atlas, 10 July 2025
Cite this Entry
“Portland cement.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Portland%20cement. Accessed 22 May. 2026.
Copy CitationKids Definition
portland cement
noun
port·land cement
ˌpōrt-lən(d)-
ˌpȯrt-
: a cement made of clay and limestone
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