Portland Cement
Definition
A hydraulic binder produced by firing calcium and silica sources at 1450°C; the four clinker phases (C3S, C2S, C3A, C4AF) hydrate on water addition to form the paste matrix.
- Firing temperature
- Around 1450°C
- Gypsum content
- Approximately 5 percent by weight
- Patent date
- 1824
- Type
- Hydraulic binder (sets and hardens through reaction with water)
Common questions
What is Portland cement and how is it made?+
Portland cement is a hydraulic binder created by firing limestone and clay at around 1450°C to produce clinker. The clinker is then ground with about 5 percent gypsum. When water is added, four clinker phases (C3S, C2S, C3A, C4AF) hydrate to form the cement paste matrix that binds concrete and mortar together.
Why is Portland cement important in forensic analysis?+
Portland cement is a major component of concrete, mortar, and building materials found at crime scenes. Its distinctive composition and clinker phases make it a valuable trace evidence material for comparing samples from suspects, tools, or locations.
Who invented Portland cement?+
Joseph Aspdin patented Portland cement in 1824.
Related terms
- Clinker
- The nodular intermediate product of Portland-cement manufacture, consisting of C3S, C2S, C3A and C4AF mineral phases before grinding.
- Ettringite
- A calcium sulfoaluminate hydrate that forms early in cement hydration and can re-form later from delayed sulfate attack; its presence or alteration...
- Portlandite
- Calcium hydroxide (Ca(OH)2) crystallised during cement hydration; a bright birefringent phase visible in thin section that dissolves progressively as concrete carbonates, providing...
- Alite (C3S)
- Tricalcium silicate, 3CaO.SiO2. Dominant clinker phase (50 to 70 percent). Hydrates fast, gives early strength up to 28 days.
- Aluminate (C3A)
- Tricalcium aluminate, 5 to 10 percent. Reacts violently with water, attacked by sulphate. SRC cement is low in C3A.
- ASTM C150
- US standard specifying Portland-cement composition limits and performance requirements by type (I through V); referenced in forensic mineral-phase characterisation.
- Belite (C2S)
- Dicalcium silicate, 2CaO.SiO2. 15 to 30 percent. Hydrates slow, gives long-term strength beyond 28 days.
- C-S-H Gel
- Calcium silicate hydrate, the main hydration binder. Amorphous, broad hump on XRD.
- Calcium Sulphate Hemihydrate
- CaSO4 . 1/2 H2O; produced by heating gypsum, rehydrates to gypsum on setting; the basis of plaster of Paris and most interior...
- ENFSI ENG-FG1
- The European Network of Forensic Science Institutes' guidelines for forensic geological evidence, published in 2018 by the Expert Working Group on Forensic...
- FTIR (Fourier Transform Infrared Spectroscopy)
- A vibrational spectroscopy technique used in toner analysis to identify the polymer backbone and functional group composition of toner binder material; ATR...
- Pozzolan
- A silica- or alumina-rich material (fly ash, silica fume, volcanic ash) that reacts with portlandite to form additional C-S-H gel; used as...
Explained in these topics
- Cement, Mortar and Concrete: Composition and Forensic AnalysisHydraulic cement patented by Joseph Aspdin in 1824. Made by sintering limestone and clay at around 1450°C to give clinker, then grinding with about 5 percent g...
- Cement, Plaster and Building-Material EvidenceA hydraulic binder produced by firing calcium and silica sources at 1450°C; the four clinker phases (C3S, C2S, C3A, C4AF) hydrate on water addition to form the...