Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsPortland CementPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsDefinitionA hydraulic cement capable of setting, hardening and remaining stable under water. It consists essentially of hydraulic calcium silicates, usually containing calcium sulfate.Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsManufactureRaw Materials 2/3 calcareous materials (lime bearing) - limestone 1/3 argillaceous materials (silica, alumina, iron)- clayPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsNotationCCaOSSiO2AAl2O3FFe2O3HH2OPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsCement MineralsC3S : 3CaOSiO2C2S : 2CaOSiO2C3A : 3CaOAl2O3C4AF : 4CaOAl2O3Fe2O3Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsChemical Reactions2C3S + 6H --> C3S2H3+ 3CH + 120 cal / g2C2S + 4H --> C3S2H3+ CH + 62 cal / gC3A + CSH2--> Ettringite + 300 cal / gPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsHydrated PastePortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsSolids in the Cement PasteCalcium Silicate HydrateNotation: C-S-HC/S Ratio: 1.5 to 2.0Main Characteristics: High Surface (100 to 700 m2/ g) ----> High Van der WallsForce -----> Strength.Volume % : 50 a 60Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsC-S-HPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsSolids in the Cement PasteCalcium Sulfoaluminate HydratesVolume % : 15 to 20first : ettringiteafter : monosulfate hydrated.Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsCalcium HydroxidePortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsSolids in the Cement PasteCalcium Sulfoaluminate HydratesVolume % : 15 to 20first : ettringiteafter : monosulfate hydrated.Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsEttringitePortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsOrders of magnitudePortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsASTM Portland CementsType I General PurposeType II Moderate heat of hydration and sulfate resistance (C3A < 8%) : general construction, sea water, mass concreteType III High early strength (C3A < 15%) : emergency repairs, precast, winter construction.Type IV Low heat ( C3S < 35%, C3A < 7%, C2S > 40%) :mass concreteType V - sulfate resistant ( C3A < 5%) : sulfate in soil, sewersPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsMain Components of PCMain Components of PC amount notes C3S 50% very reactive compound, high heat of hydration, high early strength C2S 25% low heat of hydration, slow reaction C3A 10% problems with sulfate attack, high heat of hydration C4AF 10% gypsum 5% used to control the set of cementPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsTypical Compound Composition of Various Types of Portland CementCompound composition range (%) ASTM type General description C3S C2S C3A C4AF I General purpose 45-55 20-3O 8-12 6-1O II General purpose with moderate 40-50 25-35 5-7 6-10 sulfate resistance and moderate heat of hydration III High early strength 50-65 15-25 8-14 6-10 V Sulfate resistant 40-50 25-35 0-4 10-20 ASTM also has Types I-A, II-A, III-A -- cements with air entrainmentPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsOther hydraulic cements a) Blended P.C b) Modified P.C. c) Non-calcium silicate cementsPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsBlended PC Type I-P P stands for pozzolan. It contains 25 to 30% of fly ash. It has low heat of hydration, develops strength over time. Type I-S S stands for slag. It contains 50 to 60% of Blast-Furnace Slag.Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsAggregates for ConcretePortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsSignificance: Cost Provide dimensional stability Influence hardness, abrasion resistance, elastic modulusPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsAggregate Type Coarse aggregate > 3/16 in. - 4.75 mm (No. 4 sieve) Fine aggregate < 3/16 in. and > 150 (No. 200 sieve)Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsAggregate Type -mineralogy Sedimentary Rocks (cost effective - near the surface), about 80% of aggregates Natural sand and gravel Sandstone, limestone (dolomite), chert, flint, graywacke Metamorphic Rocks: slate, gneiss  Excellent to poorPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsAggregate Type -mineralogy Igneous RocksIntrusive (plutonic):coarse-grained; graniteShallow Intrusive: fine-grained; riolite, andesite, basaltExtrusive: fine-grained; tuff, pumice, basalt hard, Tough, strong : excellent aggregate.Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsIndustrial by-products used in concreteSlags: by-product of metallurgic industries Not a high quality aggregate because it has some impurities Not used for prestressed concrete Used for blocks Much more value as a cementing materialPortland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties, and MaterialsIndustrial by-products used in concreteFly-ash: by-product of burning coal (60 million ton/y in USA) Sintered or pelletized fly-ash has been used for LWA Good to be used in combination with P.C.Portland CementP.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure,