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PRATLIPERL ULTRA LIGHTWEIGHT INSULATING AND FIREPROOFING MIXES

SOME TECHNICAL INFORMATION

1. GENERAL

Pratliperl is a unique volcanic glass, a large deposit of which is found at only one location in South Africa and nowhere else on earth. Its properties are similar to classical Perlite but it differs in that the processed (expanded) form is ideally suited for use with cementitious and other binders. It also has truly exceptional fireproofing properties.

During processing, the volcanic glass ore is crushed to sugar grain size and passed through a specially developed furnace. On heating, the crushed grains of "glass" soften and water trapped within the structure turns to steam which expands or "pops" the grains into a multitude of well-sealed glass beads. During this process, much of the water vapour escapes by diffusion and much of the remaining water is re-absorbed into the glass structure. The loss of water also alters the chemistry of the glass and results in a higher melting point.

Under the microscope, each tough bead comprises a froth of glass-walled closed cells each enclosing a near vacuum (see photograph). Expanded Pratliperl is therefore best described as comprising millions of tiny sealed "thermos flasks", hence its absolutely unique and unrivalled insulating and fireproofing properties. Some of the unique properties and the physical reasons for them are listed below:

1.1 Excellent thermal insulator

("k" value in the loose state of + 0.05 W/m °C.)

This property is derived from the low density and physical structure of the Pratliperl grains.

1.2 Ultra lightweight

Density in the loose state is ÷100 kg/m³ and, when mixed with cement, practical concrete densities ranging from ÷300 kg/m³ to 1000 kg/m³ can be achieved. The Pratliperl concrete will therefore float on water.

This property derives from the ore expansion ratio of ÷20 times (i.e. 1 m³ of Pratliperl ore expands to 20 m³ of product).

1.3 Exceptional Fire Resistance

Notwithstanding the high melting temperature of ÷1250°C Pratliperl concrete can also maintain its structural integrity at high temperatures due to its thermal insulating property. The latter ensures a very high thermal gradient on the outer surface during fire conditions resulting in very low temperatures immediately below the fire exposed surface. Indeed, even if the surface melts, it coalesces into molten glass beads which insulate and protect the interior.

1.4 Compatibility with Portland Cement and Other Binders

Unlike conventional Perlite, which is often friable and delicate with many fractured cells, Pratliperl has a well-sealed tough structure. This prevents severe bead damage during mixing and facilitates low water absorption, hence proper curing of the cement.

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1.5 Superior Strength

Ultra lightweight concretes are generally weak and, in the case of aerated concrete, are extremely vulnerable to total slump shortly after casting, especially if any vibration or disturbance is present.

Pratliperl concrete does not rely on air-entrainment and can be cured under any conditions of vibration. Once cured,the product exhibits surprising strength in comparison to other lightweight concretes. Strength varies with density but practical strengths in the range of 1.5 MPa up to 23 MPa are quite achievable.

1.6 Adhesion (Spray or Plaster)

Pratley has developed a chemically "Pre-treated" Pratliperl, which, when mixed with cement, can be plastered (without the use of additives) either with a trowel or by spray to most common surfaces with good adhesion. In the case of doubtful surfaces, a recognised cleaning procedure, followed by the application of a bonding agent, "Pratley Plaster Grip Primer", is recommended. In this case, Pratliperl plaster will even adhere to smooth steel.

1.7 Low Water Permeability

The Pre-treated Pratliperl, when mixed with cement in the correct ratio, can be deemed to be completely watertight- without the use of any additives (Vide Appendix A - PCI Report). Substrate corrosion is therefore minimised.

1.8 Non-toxic Dust

No dust is healthy. Pratliperl, due to its amorphous (non-crystalline) structure has however been demonstrated to be a very low health risk dust.

1.9 Zero Smoke and Zero Fumes

Due to its inorganic structure "Pratliperl" evolves zero smoke and zero fumes under fire conditions.

1.10 Amazing resistance to spalling

Under fire conditions and, more severely, under water quench conditions following extreme heat, (e.g. from a fire hose) conventional concrete will spall and lose its integrity. Pratliperl exhibits no such tendency and, following a

1fire, the material generally need not be replaced. Indeed, the two COMRO test tunnels, formerly at the West Rand Consolidated Mines, have Pratliperl linings which have endured several hundred high temperature test burns.

11.11 Test Reports: SABS, CSIR and COMRO and PCI

2 3 1 4SABS , CSIR , COMRO and PCI Test Reports are available. These include mobile hydrocarbon fire tests, plus density, permeability, smoke emission, strength tests and abrasion tests.

COMPARE PRATIPERL TO ORDINARY PERLITE

Note the good sphericity and high proportion of well-sealed strong cells of Pratliperl compared to the large number of fractured cells and poor sphericity of ordinary Perlite.

Pratliperl bead (Mag 250x) Ordinary Perlite bead (Mag 250x) · Well sealed · Poorly sealed · Good sphericity · Poor sphericity

1. Chamber of Mines Research Organisation - Now CSIR Mining Tech. 2. South African Bureau of Standards.3. Council for Scientific and Industrial Research. 4. Portland Cement Institute (now the Cement and Concrete Institute).

2

R1 May 2001

PRODUCTS AND PACKAGING

Pre-Treated Pratliperl 100 l bag Pratliperl 100 l bag (Product Code 99031) (Product Code 99020)

PRATLIPERL AND PRE-TREATED PRATLIPERL

Pratliperl is supplied in 10 kg (100 l) calendared, polypropylene sacks clearly printed "Pratliperl" or "Pre-treated Pratliperl".

Product Code Description99020 Pratliperl 100 l Bag99031 Pre-treated Pratliperl 100 l Bag

We recommend the use of Pre-treated Pratliperl for all cementitious applications.

PRIMER

If Pratliperl is to be plastered onto smooth surfaces, a primer may be used to ensure good adhesion. Pratley Plaster Grip Primer will even permit the plastering of ultra smooth surfaces like flat steel.

Product Code Description99026 Pratley Plaster Grip Primer 5 l plastic bucket.

____________________

NOTE: 1) If mix is to be applied to smooth surface, eg PVC or steel, use Pratley Plaster Grip Primer.2) For spray applications, use special concrete pump or spray machine. (Consult Pratley for details.)

3

Mix Ratio (by volume)Pratliperl : Cement

3 : 11 Bag Pre-treated

Pratliperl(100l ) + 1 pocket

OPC (33l )

4.5 : 11.5 Bags Pre-treatedPratliperl (150l ) +

1 pocketOPC (33l )

6 : 12 Bags Pre-treatedPratliperl (200l ) +

1 pocketOPC (33l )

10 : 13.5 Bags Pre-treatedPratliperl (350l ) +

1 pocketOPC (33l )

Water (l) per 10 kg (100l )bag of Pratliperl

LowWater*

23

Highwater

29

Lowwater*

19.2

HighWater24.2

Lowwater*

19.2

Highwater24.2

Lowwater*

19.2

HighWater24.2

Slump (mm) 55 250 45 240 50 230 30+ 90+

370 635 380 580 365 565 355 570

12 16 15 18 21 21 22 21

0.17 0.16 0.18 0.19 0.16 0.16 0.12 0.12

0.14 0.14 0.17 0.17 0.15 0.14 0.10 0.10

3.7 1.9 3.4 2.0 1.5 1.1 - -

4.9 2.7 4.2 2.5 1.8 1.3 - -

14.2 5.0 12.6 5.2 3.9 2.3 - -

19.8 7.5 16.9 6.3 4.4 2.9 - -

16.9 7.3 15.6 6.9 4.7 3.10 1.2 0.8

23.0 10.0 19.0 8.7 6.0 4.3 1.7 1.4

Flow (mm)

Measured air content (%)

Drying Shrinkage (%)

Wetting expansion (%)

7-day ISO flexural strength(Mpa)

7-day ISO compressivestrength (Mpa)28-day ISO compressivestrength (Mpa)7-day 100mm cube strength(Mpa)28-day 100mm cube strength (Mpa)

Wet density (kg/m³) 1400 1150 1250 1000 900 800 750 7001100 900 800 650 550 450 360 350Dry density (kg/m³)

28-day ISO flexural strength(Mpa)

*Recommended water content as indicated in boldThe above are expected values using quality OPC, standard mixing times, proper curing practice and correct water ratio.

*NB! The water : cement ratio is very important. Numbers shown are per 100 l of Pre-Treated Pratliperl.

TYPICAL PROPERTIES

3 : 11 Bag Pre-treated

Pratliperl(100l ) + 1 pocket

OPC (33l )

4.5 : 11.5 Bags Pre-treatedPratliperl (150l ) +

1 pocketOPC (33l )

6 : 12 Bags Pre-treatedPratliperl (200l ) +

1 pocketOPC (33l )

10 : 13.5 Bags Pre-treatedPratliperl (350l ) +

1 pocketOPC (33l )

NOTE:- Before selecting a mix, check structural design and properties.

= For improved fire resistance use 1 x 5kg bag “Pratley Fire Mix Additive”. 3 = suitable* For smooth substrate surfaces use “Pratley Plaster Grip Primer”. x = not suitable “OPC” = Ordinary Portland Cement

SUITABILITY GUIDE

External Plaster * =TYPICAL APPLICATIONS

Mix Ratio (by volume)Pratliperl : Cement

3 3 X X

3 3 3 X

3 3 X X

3 3 3 X

3 3 3 3

3 3 3 3

3 3 3 X

X X 3 3

Internal Plaster * =

Built-up floors

Insulating roof Decks

Fire Seals

Castables

Spray Applications *

Cast Thermal Insulation

4

HOW TO MIX PRE-TREATED PRATLIPERL WITH CEMENT

IntroductionAll the principles of good concrete practice apply to Pre-treated Pratliperl mixes.

EquipmentA mechanical means of mixing is suggested. A pan mixer is preferable as a drum mixer tends to make balls.If this equipment is not available, manual mixing with shovels is acceptable.

As Pre-treated Pratliperl is a non-absorbent volcanic glass, water will not be absorbed into the material. The use of a sealed, leakproof container is, therefore, recommended to prevent leaching of the required amount of water.

1. Mix Pre-treated Pratliperl and cement in the dry state first (a little water may be used to dampen slightly in order to suppress dust).

2. Add the correct amount of water (refer to the table on Page 4 - and note that the water quantity is given in litresper 100 l of Pre-treated Pratliperl!). The product may appear very dry, especially if hand-mixed, but this is correct.It is important to monitor the amount of water added since small differences in water content have a large effect on overall consistency and slump.

3. Mix, but do not overdo, mixing time - about 30 seconds in a pan mixer is all that is required (longer mixing entrainstoo much air).

Yield! Approximately 11 bags Pre-treated Pratliperl will be required for each cubic metre of concrete/plaster to be mixed

(cement and water to be added to this quantity of Pre-treated Pratliperl). This applies to all mixes mentioned in the table of Typical Properties (page 4).

Gunnite and Loose-fillPre-treated Pratliperl concrete may also be gunnited. Because lower air velocities are used than for ordinary gunniting procedures, the rebound is lower. A further advantage is that the rebound can be re-used.

Pratliperl can also be used as a loose-fill (without cement) to fill cavities for thermal insulation purposes.

Some Very Important Tips1. The water content is extremely important. Too much water will yield poor results and lead to shrinkage, weak

concrete and cracking. Use only the water per table on page 4.2. When plastering, use good conventional plastering techniques. Particular attention should be paid to the degree to

which the plaster has set prior to levelling with straight edge. As with any plaster, it should be set sufficiently so that it is difficult to cause an indentation by applying thumb pressure. If the straight edge is applied prematurely, it will cause the plaster to de-bond from the wall and slump cracks will form. On smooth surfaces, use Pratley Plaster Grip Primer.

3. As with any concrete or plaster, proper curing under damp conditions and out of direct sunlight is vital for success.4. The application will determine the exact water : cement ratio. For example - for casting and plastering applications,

the user may decide to use the high water content (refer to the table on Page 4), whereas for screeds a drier consistency and stronger product may be preferred, hence the low water content may be chosen.

5. Once applied, the surface must be kept moist for the first 14 days while curing. If the finished product is to be exposed to direct sunlight or fast cured, contact our office for advice on specialised additives.

ExampleI wish to plaster my company's computer room internally to improve thermal insulation:-1. Referring to the suitability guide, a 4.5:1 mix is selected since it can be plastered with ease and has sufficient

strength.2. The wall area of the room is 80 m² and the plaster is to be 30 mm thick. Assuming 11 bags Pretreated Pratliperl per

m³: for 2.4 m³, I will need 2.4 x 11 bags (each 100 l) of Pretreated Pratliperl, i.e. 26.4 (or 27) bags. For a 4.5:1 mix, this requires 17.6 (or 18) x 50 kg pockets cement (33 l each), since 1 pocket of cement is required for every 1.5 bags Pretreated Pratliperl.

3. The high water option should improve plasterability. The table indicates that 24.2 l of water is required for every 100 l bag of Pretreated Pratliperl used.

4. The Pratliperl and cement are first mixed in the dry state. Water is then added and mixed in further. This may be done on a non-absorbent floor using a spade.

5. As the substrate is smooth, Pratley Plaster Grip Primer is painted on before plastering to ensure adhesion. The plaster is applied in the conventional way, once the Pratley Plaster Grip Primer has dried until "just tacky" (approximately 10 - 20 minutes).

6. Once the plaster is set beyond the gel stage, a straight edge is used gently to obtain a flat surface.7. It is then float finished; first wood float with a little water splashed on with a brush, and then by using a steel trowel.8. Finally, it is covered with wet hessian - sprayed regularly for the first 72 hours to ensure that it remains damp.

Mixing Instructions

5

APPENDIX A

TEST REPORTS

The pages of this Appendix comprise summaries of official test reports issued by:·! CSIR (Council for Scientific and Industrial Research)! SABS (South African Bureau of Standards)! PCI (Portland Cement Institute - now the Cement and Concrete Institute)! COMRO (Chamber of Mines Research Organisation) - Now CSIR Mining Tech.

They have the following titles:

CSI - The Fire Properties of Pratliperl Panels.SABS - Hydrocarbon Fire Tests (and Fire Resistance on Cable Penetrations).SABS - Fire Exposure Tests on Protected Steel Columns

(2 500 mm x 200 mm x 150 mm).SABS - Thermal Conductivity Tests.SABS - Surface Fire Index on Pratliperl.SABS - Non-Combustibility Test on Pratliperl.PCI - Evaluation of "Pre-treated Pratliperl".COMRO - Heat Gain Measurements on Pratliperl Insulation Systems

Condition of panels afterapplication of hose steam.

Hose stream application after one minute.

Slight inwards dashing ofthe panels after 3 hours.

6

R1 May 2001

CSIR - THE FIRE PROPERTIES OF PRATLIPERL PANELS

A summary of a report undertaken by The Division of Building Technology, CSIR follows (the complete report is available for inspection upon request).

Procedure: Three large panels (3 m x 1 m x 75 mm, masses 102 kg, 142 kg, and 182 kg, respectively) consisting of Pratliperl aggregate with portland cement binder applied over "Spaceframe" reinforcing cage were tested for non-combustibility (SABS 0177: Part 5), for suitability as transformer fire shield and for fire-resistance, using the standard time-temperature mode.

Results:

Non-combustibility - Temperatures recorded are presented in Figure 1.

Transformer Fire Shield TestThe maximum deflection, in the form of slight inwards (into the furnace) dishing was 15 mm in the centre of the panels. This slight dishing after 3 hours exposure can be seen in the enclosed photographs.

The condition of the fire-exposed face of the panels immediately after the test and after shock quenching can also be seen in the enclosed photographs.

The fire-exposed surfaces of the panels showed only surface cracking, with none of the cracks extending through the thickness of the panels. There were no signs of spalling and the panels were strong enough to be removed from the furnace frame without the panels disintegrating.

Fire ResistanceoAverage temperature on cold face of panel after 2 hours fire-exposure = 70 C.

oFurnace temperature = 1 055 C.Calculations indicate that a 75 mm thick panel made of Pratliperl with a density of 1 000 kg/m³ will have a fire-resistance of at least 4 hours, as a non-loadbearing element.

Conclusions:! Pratliperl is non-combustible and liberates no smoke or toxic gas on exposure to fire.! Unlike normal concrete panels, Pratliperl panels with "Spaceframe" reinforcing do not spall and deflect only slightly on

exposure to fire. Heat-flow through these panels is substantially less than through normal concrete of equivalent thickness.

! The panels also did not disintegrate or spall explosively when subjected to a hose stream when hot, like ordinary concrete panels do.

Fire shields constructed of Pratliperl panels will effectively protect adjacent equipment such as transformers from radiation and conducted heat from a transformer oil fire for periods of at least 4 hours. When used as a non-loadbearing element in buildings or for other applications, a fire-resistance rating of at least 4 hours can be allocated to 75 mm thick panels with a density of 1 000 kg/m³.

FIGURE 1 - Temperatures recorded in furnace

(PRE-TREATED PRATLIPERL PANELS)

0

200

400

600

800

1000

0

20

40

60

80

10

0

12

0

14

0

16

0

18

0

20

0

22

0

24

0

Time (minutes)

Te

mp

era

ture

(o C)

Aver age surf. temp. (102 k g pane l)Average surf. temp. (142 kg panel)Average surf. temp. (182 kg panel)Average exposed face temp.

7

SABS - HYDROCARBON FIRE TESTS

A summary of reports undertaken by the SABS, 20 June 1991 [Ref. 19/03/21/07; Report Nos 653/82280/H3723/A, B, C, D, E] follows (the complete reports are available for inspection upon request).

A series of tests was conducted to evaluate samples for cable protection in high risk fire areas.

Test Procedure:

A cable tray was installed in the removable wall of a vertical furnace, extending approximately 800 mm horizontally into the furnace. A cable length was installed in the tray in such a manner as it formed a loop. The cable tray was filled with the plaster mixes described above. Thermocouples were attached to the cable, one to the top of the cable, one underneath the cable and one to the side of the cable. The compositions described were exposed in the vertical furnace, in accordance with the procedures described in SABS 0177II. During the test, a 220 V electrical current was passed through two conductors of the cable. The current was used to glow an electric light bulb. The time at which the bulb failed to glow was recorded. The temperature/time curve recorded was the hydrocarbon fire curve, also known as the "Mobile Fire Curve".

Table I: Results of Hydrocarbon Fire Tests

Remarks: The exposure of materials to a simulated hydrocarbon fire (Mobile Fire Curve) is a method to study the behaviour of materials under defined fire conditions. The designer of a specific construction can use the information obtained to decide on the parameters to be specified for specific applications.

SABS - FIRE EXPOSURE TESTS ON PROTECTEDSTEEL COLUMNS

A summary of reports undertaken by the SABS, 15 July 1991 [Nos 653/82280/H3724 and H3725] follows (the complete reports are available for inspection upon request).

Sample:Standard H Section Steel Columns, 2 500 mm x 200 mm x 150 mm, with an average flange thickness of 15 mm and a weft thickness of 10 mm were protected as follows:! The steel surface was treated with Pratley Plaster Grip Primer.! A layer of plaster material, 30 mm thick, was applied to the column

5:1 Pratliperl : OPC3:1 Pratliperl : OPC

Nature of Tests:The tests were conducted in a vertical furnace in accordance with procedures described in code of practice SABS 0177-II.

Observations and Remarks:A 5:1 Pratliperl : OPC: At the end of the 120 min test procedure, the average steel temperature was 307°C and a single highest point reached a temperature of 314°C (furnace temperature 1046°C)B 3:1 Pratliperl : OPC: At the end of the 120 min test procedure, the average steel temperature was 364°C and a single highest point reached a temperature of 384°C (furnace temperature 1050°C).

Temperatures recorded during hydrocarbon fire test

3:1 PRATLIPERL FIRE-MIX : OPC

0

200

400

600

800

1000

1200

0 20 40 60 80 100 120Time (min)

Te

mp

era

ture

(o C)

A (top of cable) A (beneath cable) A (side of cable) A (furnace)

Sample

3:1 Pratliperl fire-mix : OPC

Mimimum Cover Thickness over Time Taken by Light Bulb to Stop

10335

8

SABS - THERMAL CONDUCTIVITY TESTS

A summary of reports undertaken by the SABS, 5 August 1996 [Nos 722/82402/4249] follows (the complete reports are available for inspection upon request).

Method of Testing:

Samples A-D were tested on a Heat Flow Meter Apparatus in accordance with ASTM C518.

Table I: Results of Thermal Conductivity Tests

SABS - SURFACE FIRE INDEX ON PRATLIPERL

A summary of a report undertaken by the SABS, 16 October 1987 [Nos 653/81590/D2462] follows (the complete report is available for inspection upon request).

Sample:

Boards made of 5:1 Pratliperl : Cement.

Nature of Test:

Tests to establish the surface fire index were carried out in a tunnel furnace according to SABS 0177: Part III.

Results:

Spread of flame index 0Heat contribution index 0Smoke emission index < 0.1Surface fire index 0Class 1

SABS - NON-COMBUSTIBILITY TEST ON PRATLIPERL

A summary of a report undertaken by the SABS, 16 October 1987 [Nos 653/81590/D2463] follows (the complete report is available for inspection upon request).

Sample:Blocks made of 1:5 cement: Pratliperl.

Nature of Test:Tests to determine the non-combustibility of the material were carried out in a furnace according to SABS 0177: Part V.

Results: The sample was found to be non-combustible

MEAN TEMP.(°C)

MIX RATIO(Pre-treated

Pratliperl:Cement)

NORMALDENSITY

(kg/m³)

THERMALCONDUCTIVITY

(W/m.K)SAMPLE

A

B

C

D

25.5

25.3

25.3

25.3

3:1

4.5:1

6:1

10:1

770

670

480

360

0.15

0.13

0.12

0.09

9

PORTLAND CEMENT INSTITUTE - EVALUATION OF "PRE-TREATED PRATLIPERL”

A summary of a report produced by the PCI, 30 March 1992 [Ref. 984/94NPD/jaf] follows (the complete report is available for inspection upon request)

A series of tests was conducted to evaluate Pretreated Pratliperl. These included strength tests and limited shrinkage tests on nominal 3:1, 4.5:1, 6:1 and 10:1 (volume) mixes covering a range of consistence between 40 mm slump and 120 mm slump. In the list of tests which follow, the test procedure adopted is shown in parenthesis.

! 7-day and 28-day compressive strength on water- and air-cured specimens(SABS Method 863)

! Permeability tests at 28 days (DIN 1048)

! Wet density (100 mm cube specimens, weighing immediately after demoulding).

! Dry density and rate of moisture loss (weighing, to constant mass, 100 mm cube specimens air-dried and in a drying oven between 100°C and 110°C.

! Initial drying shrinkage (SABS Method 836).

! Wetting expansion (SABS Method 836).

! Slump (PCI TM 6.2)

! Flow (SABS Method 862-2)

! Air content (SABS Method 1252)

! Water retentivity (BS 4551)

! Consistence retentivity (BS 4551)

! ISO flexural and compressive strength (EN 196)

! Modulus of elasticity (PCI TM 7.6)

! Assessment of "plasterability" of each mix.

RESULTS

These are summarised in the table showing Typical Properties (Page 4) and in Figures 1-8.

COMMENTS

General! The water : cement (W:C) ratio is very important. It was considered better to measure properties over a range of

water contents rather than a range of slumps, since consistence achieved was dependent on mixing time.! The water requirement is fairly consistent over a wide range of aggregate : cement ratios. Water should be added

slowly during mixing over a period of time to activate the admixture in case the required slump is exceeded.

Compressive Strength! For richer mixes, water content had a large influence on the resultant consistence, compressive strength and flexural

strength. Its influence diminished as the aggregate : cement ratio increased.The compressive strengths achieved were well above average for a lightweight mortar using OPC.

! Relationship between 7-day and 28-day strengths are normal for standard-cured specimens.! Specimens dry-cured for 28 days yielded strengths approximately 70% of standard-cured specimens. At 7 days there

was virtually no difference.! Results of ISO tests follow a similar pattern.

Density! Wet densities varied from approximately 700 kg/m³ to 1 100 kg/m³. Dry densities varied from approximately

300 kg/m³3 to 800 kg/m³.! Graphs showing the rate of moisture loss are shown in Figure 1.! Specimens were virtually dry in 24 hours at 100°C (oven drying). Specimens took longer than two weeks to dry

Figure 1) when air-dried under favourable drying conditions (22,5°C, RH<50%). No micro-cracking was observed for both methods.

Permeability! According to DIN 6.5.72 a concrete with thickness of = 100-400 mm will be waterproof if maximum penetration is

not >50 mm. Further, the W:C ratio should not be > 0.6.! The 3:1 mix was deemed watertight. This may be partially due to the mix having a W:C ratio of 0.57 and partially

due to the high air content (18.5%).! The 4.5:1 mix was not tested.! The 6:1 mix was not watertight. Very little water passed through at 1 bar pressure but this increased significantly

when pressure was increased to 3 bars.! The 10:1 mix was not watertight

10

Initial Drying Shrinkage and Moisture Movement! The shrinkage values are relatively low for lightweight mortar.! The shrinkage values are only slightly affected by change in consistence but significantly affected by change in

cement content.! Wetting expansion values are above average for conventional aggregate but are quite normal for lightweight

aggregate.

Slump Testing! If slump tests are not done quickly, water bleeds from the base of the slump cone, leaving a mortar with poor

flow properties. This leads to anomalous slump readings, especially for the 10:1 mixes. In these situations the flow test is considered a better test.

Air Content! The measured air content increased with increasing consistence and with decreasing cement content.! Mostly, air contents were in the order of 20%. Notable exceptions were the rich 3:1 mixes, particularly at the

drier consistence.

Water and Consistence Retentivity! BS 4551 recommends that, when masonry cement is used, water retentivity should be between 70 and 95%.

The European standard for masonry cement (EN 413-1) specifies that water retentivity should fall between 80 and 95%. PCI believes that for good workability the value should fall between 85 and 95%.

! Water retentivity, for 3:1 and 4.5:1 mixes, was considered satisfactory. It was considered borderline for the 6:1 mix and poor for the 10:1 mix.

Plasterability! The ability to successfully plaster with the various nominal mixes is in line with the measured and observed

water retentivities.! The 3:1 and 4.5:1 mixes could be used for plaster without difficulty. The 6:1 mix could be used for plaster but

the mix lacked adequate cohesion. The 10:1 mix was unsuitable for plastering.

FIGURE 2 - PRE-TREATED PRATLIPERL

Strengths - Range of Consistence

0

10

20

30

0 5 10

Aggregate/Ceme nt Ratio (Volume)

Co

mp

ress

ive

Str

eng

th

(MP

a)

low slump high slump


Approximate Slump vs Compressive Strength

-5

5

15

25

0 100 200 300

Approximate Slump (mm)

28

da

y

Co

mp

ress

ive

Str

eng

th

(MP

a)

3:1 4.5:1 6:1 10:1


Rate of Loss of Moulding Moisture

0

100

200

300

400

0 2 4 6 8 1012141618202224262830

Time (Days)

Mo

istu

reL

oss

(g)

3:1 6:1 10:1


ISO Strengths - Range of Consistence

0.00

0.05

0.10

0.15

0.20

0 5 10

Aggregate/Ceme nt Ratio (Volume)

ISO

Co

mp

ress

ive

Str

eng

th(M

Pa

)


11

CHAMBER OF MINES - HEAT GAIN MEASUREMENTS ON

PRATLIPERL INSULATION SYSTEMS

A summary of reports undertaken by the COMRO (Chamber of Mines Research Organisation - Now CSIR Mining Tech.), in April 1989, follows (complete reports are available for inspection upon request).

The following insulation systems were tested:

1. Loose Pratliperl (thickness approximately 50 mm).2. Evacuated Pratliperl (thickness approximately 36 mm; vacuum measured to be 200 µm of mercury

[approximately 27 Pa absolute]).3. Half sections of Pratliperl with a phenolic foam binding agent (thickness approximately 52 mm).

Procedure:

Figure 1 shows the apparatus used to measure heat flow through the insulation system.

AIR

HEAT FLUXPAD

PRATLIPERL

STEEL PIPE

CHILLEDWATER

SURFACE FORRADIANTHEATTRANSFER

Figure 1: Cross Section Through Insulated Pipe and Heat Flux Pad in situ.


Densi ty vs Air/Cement (vol) Ratio

-400

100

600

1100

1600

0 5 10

Air/Cem ent Rati o (vol))

Den

sity

(kg

/cu

m)

wet den sity - l ow slu mp wet density - high slump

dry densi ty - low slump dry density - high slump


Water Content vs Slump

150

200

250

300

0 100 200 300

Approximate Slump (mm)

Wa

ter

Co

nte

nt

(l/c

um

)

3:1 4.5:1 6:1 10:1


Air/Cement Rat io (vol) vs Compressive Strength

-5

5

15

25

0 5 10

Air/Cem ent Rati o (vol)

28

da

y

Co

mp

ress

ive

Str

eng

th(M

Pa

)



Cement Content vs Air/Cement Ratio (vol)

0

200

400

600

0 5 10

Air/Cem ent Rati o (vol))

Ap

pro

xim

ate

Cem

ent

Co

nte

nt

(kg

/cu

m)

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Water Velocity(m/s)

SAMPLE 1Loose

Pratliperl

SAMPLE 1Loose

Pratliperl

SAMPLE 2EvacuatedPratliperl

SAMPLE 2EvacuatedPratliperl

SAMPLE 3PhenolicBinder +Pratliperl

SAMPLE 3PhenolicBinder +Pratliperl

PARAMETER ACTUAL TEST CONDITIONS ANGLO AMERICANSPECIFICATION

0.9 0.90.9 0.9 1.0 1.0 1.0

6.4 6.3 5.8 5.0 5.0 5.0

33.2 34.2 34.0 32.0 32.0 32.0Air Temperature(°C) db

Water Temperature(°C)

Air Velocity (m/s) 6.5 6.5 6.5 5.0 5.0 5.0

14.5 7.8 10.9 15.2 8.0 10.5Heat Gain (W/m)

Results:

Table I lists the test conditions and the measured heat gain under these conditions, compared to the corresponding heat gain under the conditions listed in the Anglo American specification for thermal insulation of chilled water reticulation piping

Table I: Test Conditions And Results

The heat gain value measured under the above test conditions was used to calculate the equivalent thermal conductivity of the insulation system:-

Sample No 1:-Heat gain: 14.5 W/m (corresponds to an effective thermal conductivity of

0.049 W/mK ± 10%).Anglo American specification: 15.2 W/m (Max.)





_________________________________________________________________________________________________

APPENDIX B

The pages of this Appendix comprise extracts from literature supplied by the Perlite Institute of New York.

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