June/July 2022 ASCE-NH Newsletter June/July 2022 - Page 6

“ PORTLAND CEMENT ”

Usually when someone hears the words “ Portland cement ” they instantly think of the yellow 80-pound bags of Quikrete you can buy at the hardware store . Just add water and “ BAM ” you have concrete . Portland cement is the fine gray powder that bonds aggregate and sand together in concrete . Portland cement is a hydraulic cement , hence it derives its strength from the chemical reaction between water and cement This process is know as hydration . Hydration is an exothermic reaction that releases energy in the form of heat . ASTM C150 lists the five different types of Portland cement used .
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Type I Portland cement is general purpose cement . This is standard cement used for construction or the bags you can get at the hardware store . Applications include sidewalks , culverts , concrete pipe , and tanks .
Type II Portland cement is used for moderate sulfate resistance or less heat is required during hydration . Applications for type II cement are piers , bridge abutments , retaining walls , precast concrete , and any structures anticipating contact with sulfate in soil or water .
Type III Portland cement has high early strength and causes rapid hardening of concrete . Type III is used when formwork needs to be stripped quickly after the concrete pours .
Type IV Portland cement is low heat cement and is used in applications where too much heat during hydration is undesirable dams .
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These applications are larger scale concrete structures such as
Type V Portland cement is used for high sulfate-resistant applications .
Sources : 1 . https :// www . engr . psu . edu / ce / courses / ce584 / concrete / library / construction / curing / Hydration . htm
2 . https :// www . thomasnet . com / articles / plant-facility-equipment / types-of-cement-used-in-construction-and-civil-engine ering /# types-of-cement
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