-
ULTRALITE PERLITE CONCRETE GRADE (CG)
Perlite is a type of non-metallic volcanic mineral which when heated to suitable temperature, will
expand from 4 to 20 times its original volume. Each separate expanded perlite particle contains a
multiplicity of non-conductive tiny air cells accounting for the lightweight and excellent thermal insulation.
Ultralite Perlite Concrete Grade (CG) combined with portland cement and water produces an
ultralightweight concrete that is used for insulating roof deck, curtain wall system and for a variety of
permanent insulating applications. An air entraining agent is used to improve the workability to control
water content and insulating value. Ultralite Perlite Concrete Grade (CG) may be more accurately
defined as concrete containing a minimum of 20 ft³ of perlite concrete aggregate per cubic yard.
-
TECHNICAL DATA
* % Free Moisture Maximum 0.5%
Loose Weight (pcf) As desired
* Soluble in hot concentrated alkali and hydrofluoric acid.
* Slightly soluble (Approx. 0.1%) in dilute mineral or concentrated weak acids.
I. MIX DESIGN CONSIDERATIONS:
The insulation value, deadload and strengths are all controlled by the final density
or weight per cubic foot of the concrete. Thus as the density increases, the strenght and
deadload also increases but the insulation value decreases.
II. TYPICAL DESIGN DATA AND SPECIFICATION PROPERTIES FOR ULTRALITE
PERLITE CONCRETE GRADE (CG)
|
Wet
Density
|
Dry
Density
|
Compressive
|
Mix
|
|
|
at
Point of
|
Range
|
Strength
|
Ratio
|
Cement
|
UL
- CG
|
Water
|
AEA
|
|
Placement
|
(PCF)
|
Range
(Psi)
|
-
|
kgs.
|
bags
|
liters
|
liters
|
|
50.5
± 2.0
|
33.5
- 40.0
|
350
- 500
|
1:4
|
30
|
1
|
27
|
1
|
|
45.5
± 2.0
|
29.3
- 32.5
|
230-
340
|
1:5
|
24
|
1
|
26
|
1
|
|
40.5
± 2.0
|
24.0
- 28.0
|
140
- 200
|
1:6
|
20
|
1
|
24
|
1
|
|
36.5
± 2.0
|
20.0
- 24.0
|
80
- 125
|
1:8
|
15
|
1
|
24
|
1
|
Notes: *AEA = AIR ENTRANING AGENT
* Data subject to minor modifications due to variations in mixers and job conditions.
* Data taken from Perlite Institute Inc. Technical Data Sheet No. 4-3, 1969
-
MATERIALS SPECIFICATIONS
CONCRETE GRADE PERLITE conforms to ASTM C 332-66, Group I classificaion
CEMENT conforms to ASTM C 150, Type I, II or III
WATER must be free and clean of deleterious substances
AEA - Air Entraining Agent shall be as recommended by manufacturer of ULTRALITE PERLITE
CONCRETE GRADE.
* (RECOMMENDED - ULTRALITE PERLITE CONCRETE GRADE)
-
DENSITY SELECTION GUIDE FOR ULTRALITE PERLITE CONCRETE AGGREGATES (CG)
Dry Density Range, (PCF):
40 pcf and above - for heavier fills and unheated slabs like floor slabs and other lightweight structural
applications. This is usually blended with sand or heavy aggregates.
34 - 40 pcf - where higher strength of concrete is more important than insulating value like floor
fills and other hanging dead load.
28 - 34 pcf - where combination of strength and insulating properties are required.
24 - 28 pcf - offers an ideal balance of reduced dead load, strengths, and good insulating value
like roofdeck topping.
20 - 24 pcf - where perlite concrete is not required to provide structural strength, insulation and
lightweight properties are considered.
III. TYPICAL MIX DATA FOR "ULTRALITE PERLITE" (CG) AND SAND CONCRETE MIX
| |
Compressive
Strength
|
|
|
.Wet
Density
|
Dry
Density
|
Range
|
Cement
|
CG
|
Sand
|
Water
|
AEA
|
|
lbs/ft³
|
kg/m³
|
lbs/ft³
|
kg/m³
|
lbs/in²
|
ft³
|
Bags
|
ft³
|
liters
|
liters
|
|
82±5
|
1312±80
|
55-65
|
1040
|
400-600
|
1
|
1
|
0
|
26
|
<
1
|
|
98±5
|
1568±80
|
65-75
|
1200
|
600-800
|
1
|
1
|
1
|
28
|
1
|
|
105±5
|
1680±80
|
75-85
|
1408
|
800-900
|
1
|
1
|
2
|
30
|
1
|
|
110±5
|
1760±80
|
85-95
|
1584
|
900-1200
|
1
|
1
|
3
|
32
|
1
|
-
MATERIAL SPECIFICATION FOR ULTRALITE PERLITE AND SAND CONCRETE MIX
A - Cement shall conform to ASTM C 150 Type I or Type III
B - ULTRALITE PERLTILE (CG) (Conform to ASTM C 3320 or upon recommendation of manufacturers)
C - Sand shall conform to ASTM C 33
D - AIR ENTRAINING AGENT (AEA) shall be recommended by the perlite producer
E - Water shall be clear of deleterious substances.
F - Reinforcing mesh shall be style 2160 and 1619 galvanized mesh or 48-1214 galvanized welded wire fabric.
-
APPLICATION OF "ULTRALITE" CONCRETE GRADE (CG)
1. As cutain wall, partition walls, fire walls, roof deck insulation panels, precast concrete articles and
non-load walls.
2. Plastering aggregates for insulation, fire proofing, sound proofing and decorative effects.
3. Floorfills/lightweight hollow block, reduce the dead load in multi-story buildings.
Perlite insulating concrete is the ideal underslab insulation; it is resistant to fungus, decay, mildew, vermin, and
moisture. The increased economy and convinience of floor slab on grade construction has resulted in extensive
use of this system in industrial, commercial, school and residential construction. However, coupled with its many
advantages is the necessity for special insulation to prevent cold floors and condensation.
-
GUIDELINES FOR APPLICATION
1. JOB MIXING
Perlite insulating concrete should be mixed in mechanical mixer. The required amount of water as
specified or predetermined, for the batch is placed in the mixer, followed by the air entraining agent
(AEA), cement and perlite aggregates. The batch is then mixed until workable with a slump of
approximately 7 (about 1 1/2 to 3 miin). Then wet density of the concrete is checked against the
specified range for confirmation, discharged and placed immediately. Mixing time is governed by the
type of equipment used and can be determined by checking the wet density of the perlite concrete at
intervals until the specified wet density is reached.
2. TRANSIT MIXING
1) Determine the load of the mixer and add the correct amount of water for the batch under chragging the
mixer by 0.76 cubic meter (1 cu. yards).
2) Add the recommended amount of air entraining agent (AEA) and cement to the mixer and mix until a
slurry is formed.
3) Add the required number of bags of ULTRAILTE PERLITE CONCRETE (CG).
4) Do not rotate the drum during transit. Upon arrival at the job site mix at top speed for about 5 minutes.
5) Check wet density for conformance to the specification range and discharge. Rotate the drum at idle
speed when discharging last of load to insure complete discharge of concrete.
6) Do not wash out drum between loads. Care must be undertaken to provide proper mixing time for
the perlite concrete (CG). Using the correct amount of water the perlite concrete should have a slump
of approximately 7 when properly mixed but may appear too wet by normal concrete practices.
However, if the mix appears dry or stiff, the mixing time has probably been too short and mixing should
be continued until the desired plasticity is reached. Extra water and undermixing may reduce the yield.
Do not add more water.
3. WET DENSITY
The wet density of the perlite concrete can be determined as follows:
1) Using convenient container, such as a one gallon can, determine its volume. This is done by first,
weighing the container empty, then, filling it level-full with water and weighing it again and subtracting
the two weights. This gives the net weight of the volume of water and divide by the density of water,
the result is the volume of the container (This will be explained further by the manufacture if not fully
understood).
2) Fill the container with the wet perlite concrete then weigh again. Subtract the weight of the empty
container and divide the remainder by the volume as determined on Step I above. The result is the wet density
of the perlite concrete.
3) The density of water is 62.4 pounds per cubic feet.
4. YIELD
The yield and percentage of yield of the perlite concrete is computed as follows:
a) YIELD = Weight of Total Ingredients / (Wet Weight of Concrete/Cu. Ft)..
b) YIELD = (Yield / Total Cu. Ft. of Perlite (CG) Used) X 100
-
LOSS OF YIELD
If the yield checked by the wet density method is less than 100%, a "loss of yield" is evident.
A loss of yield may be attributed to one or more of the following factors which should be checked:
1) Air Entraining Agent (AEA) - Be sure the proper type and amount of air entraining solution
is being added to each mix.
2) Mixing Procedure - Be sure that the materials are added to the mixer in the proper order.
Undermixing of the perlite concrete will usually result in a loss of yield. Overmixing can
adversely affect air entrainment.
3) Water - Check the quantity of water added to the mix. After about one minute of mixing,
properly proportioned perlite concrete often looks too dry and field personnel add water for
plasticity. Extra water sometimes reduces yield. Usually hard water offsets the effects of the
air entraining agent, and the perlite manufacturer should be consulted for additional air
entraining recommendations.
4) Types of Bases - In some cases even though the yield of the perlite concrete is correct as
discharged from the mixer, more materials are required for the job than estimated. When
estimating the cubic yards of perlite required, consideration must be given to type of base
used. Some bases sag slightly between supports and additional concrete is required to give a
level top surface; others allow small quantities of the concrete to drop through and be wasted.
Depending on the type of base used, an average concrete thickness should be used for
estimating and small addition made for waste.
-
DESIGN CONSIDERATIONS:
1) Control Joints
All building materials experience expansion and contraction to some extent when exposed
to changes in temperature. To compensate for this "thermal expansion", provision must be
made for control joints in both structural steel and reinforced concrete designs.
In roof-deck construction, the insulating concrete is the first rigid material to receive the
effects of hot summer sun. The top surface can reach a temperature of 150ºF, or more on a
typical summer day, which would represent up to a 100ºF temperature difference for concrete
which may have been placed in cooler months (50ºF Average). For a 27 density perlite concrete
roof slab, 100 ft x 100 ft, the above temperature conditions could show the following thermal
expansion 0.0000048 x 100 ft. x 12 ft. x 100ºF = 0.576" per lineal ft.
It is therefore recommended that at least a one inch control joint be provided through the
thickness of the perlite concrete at the juncture of all roof projections, such as skylights, penthouse
ventilators, parapet walls and perlite concrete. This recommendation assumes that suitable
consideration has been given to the use of adequate through - building control joints.
Most joint materials suitable for use as control have compressive material which will compress
to one-half its original thickness under a load of 25 psi is recommended.
2) Placement
Perlite concrete should be conveyed from the mixer to the place of final deposit by methods which
will prevent segregation or loss of material. Equipment for conveying perlite concrete should be designed
to insure delivery without separation of materials or serious loss of air content.
If pumping is employed, it should be in accordance with recommendations of the perlite concrete
and shall meet the specified physical properties at the point of placement.
Perlite concrete should be deposited and screened in a continuous operation until the placing of a
panel or section is complete. Rodding, tamping, vibrating or trowelling are not recommended.
3) Curing
The built-up roofing should be applied as soon as the perlite insulating concrete can carry construction
traffic and is dry enough to develop adhesion with hot asphalt or pitch.
Normal conditions: Perlite concrete has an adequate mixing water content so as to have sufficient water
for proper curing of the concrete without additional precautions. Under these conditions the concrete should
be permitted to air cure.
Extreme Dry Conditions: When perlite concrete is placed during extreme dry weather, additional water
may have to be sprinkled on the concrete for a sufficient period of time to allow hydration of the cement and
for a short period therefore to minimize shrinkage cracking.
TYPICAL MIX DATA FOR ULTRALITE SAND CONCRETE
| Cement (sacks) |
1 |
1 |
| Ultralite (CG) |
3 |
2.4 |
| Sand (cC) |
2 |
1.5 |
| AEA* (oz.) |
12 |
10 |
| Water (gal/sack) |
8.2 |
8.1 |
| Cement (factor/yd
- 100% yield |
5.87 |
7.44 |
| Density (Wet) |
83 |
84 |
| Density (Dry) |
69 |
74 |
| Compressive
Strength (28-day, psi) |
1000 |
1200 |
TYPICAL MIX DATA FOR ULTRALITE PEA GRAVEL CONCRETE
| Cement (sacks) |
1
|
| Ultralite (cf) |
4
|
| Pea Gravel (cf) |
1
|
| AEA* (oz.) |
4
|
| Water (gal/sack) |
10
|
| Density (Wet) |
94
|
| Density (Dry) |
75
|
| Compressive Strength (28-day,
psi) |
1300
|
TO COVERT FROM TO MULTIPLY BY
|
pound per cubic foot
(lb/ft³)
|
kilogram per cubic
meter (kg/m³)
|
1.601 846 x 10
|
|
pound-force or square
inch
|
.
|
.
|
|
(lbf/in2,psi)
|
Pascal Pa
|
6.894 757 x 10³
|
|
cubic foot (ft³)
|
cubic meter (m3)
|
2.831 685 x 10-²
|
|
Gallon (U.S.) (gal)
|
Liter (L)
|
3.785 412
|
|
Pint (U.S.) (pt)
|
Liter (L)
|
4.731 765 x 10²
|
|
