Transcript chemistry concrete pertemuan 06

Matakuliah : S0372 – Kimia Teknik Sipil
Tahun
: Ganjil 2007/2008
CHEMISTRY CONCRETE
PERTEMUAN 06
CHEMISTRY CONCRETE
• Aggregate.
• Additional Materials.
Bina Nusantara
AGGREGATE
Aggregate content in concrete mixture usually very high.
Pursuant to experience, the aggregate composition gyrate
60 - 70% from concrete mixture weight.
Although its function only as filler, but because its big
enough composition, this aggregate even also become
important.
Aggregate which is used in concrete mixture can in the
form of natural aggregate or artificial aggregate.
In general aggregate can be differentiated pursuant to its
size measure, that is harsh aggregate and smooth
aggregate.
Bina Nusantara
Bina Nusantara
Classification aggregate pursuant to source of material.
Things required to paid attention to relate to usage of aggregate in concrete
mixture :
1. Air Volume
Air which there are in concrete mixture will influence the process of
concrete, especially after formed its of cement pasta.
2. Solid Volume.
Density of aggregate volume will influence weight fill and concrete
become.
3. Specific gravity aggregate.
Specific gravity aggregate will influence mixture proportion in weight as
control.
4. Absorbtion.
Absorbtion have an in with to specific gravity.
5. Rate irrigate surface of aggregate.
Rate irrigate surface of aggregate have an in with usage of mixing
moment water.
Bina Nusantara
ADDITIONAL MATERIALS.
Admixture is enhanced materials into concrete mixture at the
time of or during mixing take place.
Function of this materials is to denature from concrete in order
to become more suited for certain work, or to cost effective.
Admixture in Standards Definition of Terminology Relating to
Concrete and Concrete Aggregates is defined as material
besides water, aggregate, hydraulic cement which mixed in
enhanced mortar or concrete before or during squealer take
place. used Additional materials to modify the nature of and
characteristic of concrete, for example to be able to, it is easy
to be done, thrift or for the purpose of other like thrift of energy.
Bina Nusantara
Additional Type Materials.
In general additional materials which used in concrete can be
differentiated to become 2 that is chemical admixture and
additional materials which have the character of mineral
(additive).
Additional materials of admixture enhanced by squealer
moment and or moment pelaksaan of moulding (placing) while
additional materials which have the character of mineral
enhanced by squealer moment executed.
Bina Nusantara
Additional Materials of Chemistry :
1. Type A “Water – Reducing Admixtures”
Is materials add lessening needed to water yield
concrete with certain consistency.
Materials add reducing of water can come from
organic materials nor inorganic mixture for
concrete without air (non-air-entrained) or with air
in the case of lessening content irrigate mixture.
Besides materials add this can be used to modify
time fastener of mortar or concrete as impact
change of cement water factor.
Bina Nusantara
Composition of materials mixture add this classified in general
become 5 class:
a. Acid of Lignosulfonic and salt content.
b. Modification and sour generation of salt content and
lignosulfonic.
c. Hydroxylated carboxylic acids and its salt content.
d. Modification hydroxylated carboxylic acids and its salt content.
e. Other material like :
 Inorganik material, example : zinky, salt, barracks, posfat,
chloride
 Acid of Amino and its generation
 Karbonhidrat, sour sugar and polisakarin.
 Polymer mixture, like ether, generation of melamic, naptan,
silicon, hidrokarbon-sulfat.
Bina Nusantara
2. Type B “Retarding Admixtures”
Retarding admixtures [is] materials add functioning
to pursue time fastener of concrete. Its use to delay
time fastener of concrete (setting time) for example
because hot wheater condition, or lengthen time for
condensation to avoid cold joints and avoid impact
degradation of fresh concrete moment at the time
of moulding executed.
Bina Nusantara
3.
Type C “Accelerating Admixtures”
Accelarating Admixtures is materials add functioning to quicken
cordage and development of strength early concrete.
This materials is used to lessen the the duration draining time
(hidrasi) and quicken attainment of strength at concrete.
Most famous Admixtures Accelerating is chloride calcium.
functioning Other materials as accelerator for example is salt
compound like chloride, bromide, carbonate, silicate and
sometimes other organic compound like tri-etanolamin.
Maximum dose is 2% from used cement weight.
Grouply materials add this divided to become three : (1) Organic
condensation salt, (2) Organic condensation mixture, (3) Material
of miscellaneous.
Bina Nusantara
4. Type D “Water Reducing and Retarding Admixtures”
Is materials add double-duty that is lessening the
amount of water of pencampur needed to yield
concrete with certain consistency and pursue
cordage early.
This extant to materials almost everything melt.
Water which implied in this materials will become
the part of concrete mixture water. Become in the
plan irrigate this have to be enhanced as total water
weight in concrete mixture.
Bina Nusantara
5. Type E “Water Reducing and Accelerating Admixtures”
Is materials add double-duty that is lessening the amount of
water of pencampur needed to yield concrete which [is] its
certain consistency and quicken cordage early.
6. Type F “Water Reducing, High Range Admixtures”
Is materials add functioning to lessen the amount of water of
pencampur needed to yield concrete with certain
consistency, counted 12% or more.
7. Type G “ Water Reducing, High Range Retarding
Admixtures”
Is materials add functioning to lessen the amount of water of
pencampur needed to yield concrete with certain
consistency counted 12% or more as well as utk pursue
cordage of concrete.
Bina Nusantara
Additional Materials of Mineral (Additive)
Additional materials of this mineral more used to improve;repair performance
depress concrete, so that additional materials of this mineral tend to to have
the character of cementation.
Some additional materials of this mineral is :pozzolan, fly ash, slag, and silica
fume.
Some advantage of usage of additional materials of this mineral for example :
a. Repairing performance of workability.
b. Lessening heat.
c. Lessening the expense of work of concrete.
d. Heightening endurance to sulphate attack.
e. Heightening endurance to attack reaction of alkali-silika
f.
Heightening concrete age.
g. Heightening strength depress concrete.
h. Heightening is durabel of concrete.
i.
Lessening decrease.
j.
Lessening absorpsion and porosity irrigate in concrete.
Bina Nusantara
a. Fly ash stone smolder
Fly ash defined as smooth item result of tilery residu or embers stone
powder. Fly ash can be differentiated to become two, that is fly ash
normal which yielded from tilery of stone or anthracite smolder ash and
bitomius fly class of C yielded of stone smolder type of lignite or of
subbitumeus. Dusty fly class of C pregnant possibility of chalk ( lime )
more than 10% weight.
Chemical Content of Fly ash
Chemical Compound
Type F
Type C
70
50
Trioksida Sulfur ( SO3 ), max %
5
5
Water Content, max %
3
3
Losing of heat, max %
6^
6
Oksida Silika (SiO2) + Oksida Alumina (Al2O3) + Oksida besi
(Fe2O3), minimum 10%
^ Usage up to 12% still permitted if there is repair of result or performance test laboratory show that way.
Bina Nusantara
b. Slag
Slag represent result of residu combustion of high kiln.
Definition of Slag in ASTM. C.989 is product of non-metal
representing material in form of refinement, granular result
of combustion is later; then made cool, for example by
plunging it in water.
Factor to determine the nature of cementation in slag is
chemical composition, alkali concentration and reaction to
system, obstetrical of glass in slag, softness, and
temperature of yg generated by during hydration process
take place.
Bina Nusantara
c. Silika Fume
Silica fume is material of pozzollan smooth, where more
silica composition witch yielded from high kiln or rest of
silicon production or of alloy silicon iron (known as aliance
between microsilika with silica of fume).
Usage of silica of fume in concrete mixture meant to yield
concrete with strength depress high, for example for the
column of wall or structure shift, concrete or pre-cast.
Usage of silica of fume range from 0 – 30% to improve;
repair strength characteristic and is durabel concrete with
water factor cement equal to 0.34 and 0.28 with or without
materials of superplastisizer value and of slump 50mm.
Bina Nusantara
Chemical Compound Silika Fume
Chemical
SiO2
Karbon
92 - 94
3 - 5
Fe2O3
0.10 - 0.50
CaO
0.10 - 0.15
Al2O3
0.20 - 0.30
MgO
0.10 - 0.20
MnO
0.008
K 2O
0.1
Na2O
0.1
Physics
Spesific gravity
Bina Nusantara
Weight in %
Weight in %
2.02
Mean particle size measure of um.
0.1
Get away sieve of No. 325 in %
99
Acidity of pH ( 10% water in slurry)
7.3