Masonry cement Types N, S and M are covered by ASTM C91, Standard Specification for Masonry Cements. Mortar cement is covered by ASTM C1329, Standard Specification for Mortar Cement. Mortar must conform to ASTM C270, Standard Specification for Mortar for Unit Masonry. Masonry cement consists of portland or blended cement, plasticizers, and an air entraining agent.
The cement industry in the United States produced million tonnes (81,500,000 long tons; 91,300,000 short tons) of cement in 2015, worth US billion, and was used to manufacture concrete worth about US50 billion. The US was the world's thirdlargest producer of cement, after China and US cement industry includes 99 cement mills in 34 states, plus two plants in Puerto Rico.