cement Flashcards
ingredients of cement are burnt at
1400 degree celsius
% of pozzolanic material in pozzolona cement
30 %
snowcem is a
colored cement
limestone used for manufacture of cement
kankar
oxide lowest in opc
soda potash
sp gravity of opc
3.15
oxide highest in opc
calcium oxide
color given by diff oxides iron magnesium cobalt chloride
iron - red
magnesium - brown/black
cobalt - blue
chloride - green
finer the cement more will be the
strength, workability, shrinkage cracking
constituent used to accelerate setting time
calcium chloride
quick setting cement is produced by adding
aluminium sulphate/alum
rapid hardening cement is obtained by
grinding clinkers to a higher degree of fineness
flash set of opc paste is
premature hardening
rate of hydration
C4AF > C3A > C3S > C2S
C4AF % in cement
8 - 10%
role of superplasticizers in cement
removing air bubbles and retarding setting time
hydrophobic cement IS code
IS 8043:1991
oleic acid used in manufacture of
hydrophobic cement
which cement produces less heat
portland pozzolana cement
cement and water when poured in formwork takes how many days to acquire fixed properties
28 days
rate of hydration depends upon which test of cement
fineness
addition of pozzolana in opc gives
decrease in early strength, redn in chemical action with sulphates, increasing shrinkage
cement used in construction in sea water
portland pozzolona cement
intial seeting time of quick setting cement
5 mins
blast furnace slag CaO & silica %
45% CaO & 35 % silica
which are fused together to form high alumina cement
bauxite and limestone
high early strength cement are obtained as a result of
fine grinding, burning at high temperatures
normal consistency of opc
25- 30%
sp gravity of cement is found by which apparatus
le chatliers flask
center needle of attachment of vicat apparatus projects circular edge by
0.5mm
for road pavement cement generally used is
rapid hardening cement
w/c ratio taken to find compr strength is
0.4
maxm thickness of a concrete floor of cement warehouse
250mm
ht of lechatlier split cylinder is
3m
principal strength contributing bogue compound
calcium silicate
steel content of ferro cemnt varies b/w
300 - 500 kg
how much % of pigment in colored / white cement
5 - 10%
For the construction of thin R.C.C. structures, the type of cement to be avoided, is
blast furnace slag cement
names of white/colored cements are
colocrete, rainbow cement, silvercrete
compared to opc high alumina cement has setting time
low intial setting time but higher final setting time
curing period is minm for which cement
rapid hardening cement
which cement is used to construct very hard thin surface
ferro cement
properties of ferro cement are
impervious nature, no need of formwork, capacity to resist shock
The cement whose strength is a little lower than the ordinary cement during the first three months but attains afterwards the same strength, is known as
Low-heat Portland cement
how many volume a 50 kg cement bag
35 cm3
batching tolerance for cement as per IS 456
+/- 2 %
what do you mean by cement warehouse
pressure compaction of bags on lower layer
addtn of pozzolana in cement results in
increased curing tym
maxm heat of hydration
C3A > C3S >C4AF > C2S
minm qty of cement needed in 1 m3 of rcc for sea weather time construction
350 kg
steam curing is not done with which cement
rapid hardening cement
