Zement, Portland-, Chemikalien Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
HELLGRAUESODER WEISSES PULVER.
CHEMISCHE GEFAHREN
Reagiert mit S?uren, Aluminium, Metallenund Ammoniumsalzen. Reagiert langsam mit Wasser unter Bildung geh?rteter hydratisierter Verbindungen, stark alkalischer L?sungen und unter W?rmefreisetzung.
ARBEITSPLATZGRENZWERTE
TLV:(Partikel asbestfrei und <1% kristalliner Quarz) 10 mg/m? Beabsichtigte ?nderung 1 mg/m?(Alveoleng?ngige Fraktion) als TWA; (ACGIH 2008).
MAK: (Einatembare Fraktion) 5 mg/m?(DFG 2008).
AUFNAHMEWEGE
Aufnahme in den K?rper durch Inhalation.
INHALATIONSGEFAHREN
Eine bel?stigende Partikelkonzentration in der Luft kann beim Dispergieren schnell erreicht werden.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Substanz reizt die Haut und die Atemwege. Die Substanz ver?tzt die Augen.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Wiederholter oder andauernder Hautkontakt kann zu Dermatitis und zu Hautsensibilisierung führen.
LECKAGE
Verschüttetes Material in Beh?ltern sammeln. NICHT in die Kanalisation spülen. Pers?nliche Schutzausrüstung: Atemschutzger?t, P1-Filter für inerte Partikel.
Beschreibung
Portland cement refers to a class of hydraulic
cements in which the two essential constituents
are tricalcium silicate (3CaO·SiO2) and dicalcium silicate (2CaO·SiO2) with varying
amounts of alumina, tricalcium aluminate, and iron oxide. It is insoluble in water. The quartz
content of most finished cements is below 1%.
Chromium may be present.
Chemische Eigenschaften
odourless fine white to grey powder
Verwenden
The majority of the cement used in construction is mixed
with sand and gravel and water at a central plant and trucked
wet to the construction site. Thus, there is little opportunity
for exposure of workers at the site to cement dust. Nevertheless,
many construction workers may be exposed to cement
dust when small amounts are mixed on site or when cement or
concrete materials are cut or ground.
Definition
A type of hydraulic cement in the form of finely
divided, gray powder composed of lime, alumina,
silica, and iron oxide as tetracalcium alumino-
ferrite (4Ca O?Al
2
O
3
?Fe
2
O
3
), tricalcium aluminate
(3Ca O?Al
2
O
3
), tricalcium silicate (3Ca O?Si O
2
),
and dicalcium silicate (2Ca O?Si O
2
). These are
abbreviated, respectively, as C
4
AF, C
3
A, C
3
S, and
C
2
S. Small amounts of magnesia, sodium, potas-
sium, and sulfur are also present. Hardening does
not require air and will occur under water. Cement
may be modified with various plastic latexes in pro-
portions up to 0.2 part latex solids to one part cement
to improve adhesion, strength, flexibility, and cur-
ing properties. Water evaporation can be retarded by
adding such resins as methylcellulose and hydrox-
yethylcellulose. For further information, refer to the
Portland Cement Association, 5420 Old Orchard
Road, Skokie, IL 60077-1083.
Allgemeine Beschreibung
A gray to white, odorless powder. A finely ground (powdered) mixture of mainly 3CaO.SiO2 (tricalcium silicate), 2CaO.SiO2 (dicalcium silicate), CaO.Al2O3 (tricalcium aluminate), 4CaO.Al2O3.Fe2O3(tetracalcium aluminoferrite) and CaSO4.2H2O (calcium sulfate dihydrate).
Reaktivit?t anzeigen
Sets in an exothermic reaction to a solid of low strength within hours after mixing with water. Continuing slower exothermic reactions harden the product to a tough gray stony mass. Incompatible with acids, acid chlorides, and acid anhydrides when set. Incompatible with ammonium salts and aluminum metal when wet and unset.
Hazard
Pulmonary function effects, asthma, respi-
ratory symptoms.
See concrete (1).
Health Hazard
Portland cement is an irritant of
the eyes and causes dermatitis.
Sicherheitsprofil
A nuisance dust. A skin
irritant. See also NUISANCE DUSTS and
AEROSOLS.
Carcinogenicity
Earlier studies have suggested increases in
various types of cancer, including lung and
stomach, with exposure to cement, but numerous limitations prevent any conclusions in this
regard.
Zement, Portland-, Chemikalien Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
