Wednesday, 8 February 2012

USM Concrete Foam


Production of Foamed Concrete
The production of foamed concrete on a small scale is a fairly easy process which does not involve any expensive or heavy machinery  and in most cases uses equipment that is already available for normal concrete/mortar production.
Depending on the volume of concrete required (normally limited to less than 20 cubic meters/day) one will only need ;
Equipment
1. Normal concrete/mortar mixer or special mixers for foam concrete.
3. Formwork (if producing pre- cast components)
Materials
1. Fine sand 
2. Cement
3. Water
Simple Mix Design
The first step is of course to decide the wet density and how much foamed concrete you require.
  • Say  volume of foamed concrete required = 0.5m3
  • Wet density of  foamed concrete required = 1000 kg/m3
The raw materials required would be ;
cement = 200 kg
sand = 200 kg (assuming dry sand)
water = 100 kg (including water in foam)
then from the target volume of  foamed concrete (0.5m3) calculate the air content and final foam volume in the mix.
  • foam content in mix = 0.25m3 ( 250 liters )
If foam output from Portafoam = 1.5 lit/sec then one would need to pump generator for 250/1.5 = 2.77 min. The practical way would be to pump for 166 sec and add the rest of  the foam using a measured container. 
Mixing procedures
Now that you have worked out the amount of  materials required to make the foam concrete add them dry first starting with the sand and cement. Mix dry constituents for a few minutes and add water in stages and make sure the mixing is thorough. Then add foam to the wet slurry and ensure foam has been completely mixed with the mortar.
After mixing is completed check that the wet density of  the foamed concrete  is close to what is required. The dry density (oven dried) of foamed concrete is normally less than its wet density, depending on w/c ratio, density and also on the cellular structure obtained. So do not forget to target a value of wet density much higher than what we actually require (dry).
  • Special training and demonstration of Portafoam and  producing foamed
    concrete for block / panel production (e.g. mix design, raw materials properties, mixing procedures, quality control, block moulds,  ancillary equipment  etc.) can be provided. We will also provide documentation along with this training and also discuss projects & experience in foamed concrete block production.








Mixers For The Production Of Foamed Concrete
One Of The Key Factors In The Production Of Foamed Concrete Is The Mixing
We have developed special mixers for the production of foamed concrete. These mixers are based on the horizontal and spiral mixing method and are quite efficient and low priced.
Sizes range from the 0.8m3 and 6m3  capacity. The mixers can be attached together with Portafoam foam generators
The basic mixer ( 0.8 m3 ) comes with a 10 HP electric motor and is transportable / movable.
Foam can be introduced via special inlets at the side or top of the mixer.
Mixing time is minimized by special design of blades which mix the foam and slurry thoroughly.







PORTAFOAM TM
(Portable Foaming Generator)
One of the most important ingredient required to produce foamed concrete is the aqueous stable foam.
The foaming generator acts as a medium which transforms the liquid chemical into stable foam. Foaming generators comes in many sizes depending on the ability to hold and transform liquid chemical into foam.
As an example , one would need about 500 liters of foam to make 1cubic meter of foamed concrete @ about 1100 kg/m3 density.  
In order to make 500 liters foam , one has to dilute say 1 liter of chemical foaming agent in 34 liters of water and subsequently transform this 35 liters of premix solution into 500 liters of foam using the generator. 
As you can see, the expansion rate is 14 times (500/35). We can increase this expansion rate by introducing more air but this will degrade the quality of the foam. Therefore the capacity of a foaming generator will depend very much on its ability to hold and pump out maximum amount of foam.
The typical foam generator runs from an air compressor and consists of a holding (filler) tank, foaming unit and a lance unit. The purpose of the holding tank is to hold the diluted foaming agent and subsequently deliver it through a foaming unit and lance. It is normally in a the form of a pressurized tank and needs to be closed tight for operation. The volume of  foam obtained from such a system depends very much on the size of these tanks. For large volumes it is impractical to use the tank system since it is bulky to carry about. Large capacity holding tanks are heavy and cumbersome for smaller scale on site production. They are also attached to the foaming unit and lance in such a way that it would be virtually impossible to detach it for future modification. 
Some foaming generators do not use a pressurized holding tank and makes use of a pneumatic or electric driven system to produce the stable foam. These generators are more versatile and are able to produce foam continuously. The are better suited to medium to large production of foamed concrete.
In line with this, we have developed a compact version of the foaming generator with an MSD Unit to cater for small to medium scalefor factory or on-site production  of foamed concrete. These foam generators are perform well since they rely on mechanical means to deliver the chemicals and are suitable for pilot plant scale production, researchers and self - help house building.
The portable foaming generator (or Portafoam ) comes in various models ( PM2, PM3) and have the capacity to produce about 100 to 600 liters of foam in one minute. They can also be used with a pneumatic delivery unit which precludes the use of pressure tanks.
It has specially designed chambers for producing the maximum and efficient output of foam. In addition some of the models have controls for modifying the density of foam and also expansion ratios.
Portafoam comes in three models ie. Model TM-2, Model PM2 and Portafoam Model PM-3. Model TM-2 has the lowest output of about 200 lit/min. Model PM-2 has output of 240 lit/min and Model PM-3 with 500 lit/min. Model PM-2 is for larger scale (up to 0.75 cubic meter / mix) continous foam production coupled with auto-timer device. All new Portafoam models are attached to a mechanical delivery unit (MSD  unit) which precludes the use of holding tanks.
However we do provide an optional coupling on Portafoam where the use of pressure tanks can be made.  This makes the Portafoam unit very unique in the sense that it can handle both tanks and MSD when required. Model TM-2 is suitable for mixing volumes of less than 0.3 cubic meter / mix and is suitable for beginners, DIY builders and some researchers.
It must be pointed however that Portafoam have been tested with Noraite  PA-1 and Noraite SA-1 (foaming agents) and are compatible with the above mentioned chemicals, conforming closely to the data explained.
                             
       PORTAFOAM Model PM-2 -    Construction of Corporate Headquaters of UEM Group K. Lumpur
  • The main unit is pictured on far right
  • The control panel with timer sits on the MSD unit
  • The lance unit is not seen in pict
Portafoam PM-2 now has been upgraged  below
  










These are some pictures of  the Portafoam system which is used for medium scale production of foamed concrete.
PM3.jpg (324757 bytes)
bulletthe above PM3 unit was used in truck batching for an airport project in Malaysia
bulletabove the main unit is the control box with timer
bulleton the right is the scaffold used to hold the lance into position to pump foam into truck mixer
bulletPortafoam PM3 requires a very good supply of air from a 5-7  hP compressor.
             PORTAFOAM TM-2 ( LIGHT AND EASY )
PORTAFOAM PM-2 (MEDIUM AND MOBILE)
bulletPortafoam system in a block factory ; East Coast Malaysia
bulletpicture above shows main unit, suction unit and control panel




MAKING STABLE FOAM
Below are some types of foaming agents which are used with Portafoam to make stable  foam required in making of foamed concrete.
1. Noraite SA-1 is a synthetic foaming agent developed at the Universiti Sains Malaysia by Norizal Md. Noordin. This foaming chemical is especially suitable for ready mixed foamed concrete (eg. used void filling & flat roof insulation) but can also be used in load bearing blocks.
It is a fairly good foaming agent for those who are just starting to use foam concrete and also for those who wish to produce AFC (air cured foamed concrete) at home (DIY). Noraite foam has average stability and can only be used where lower strength concrete is allowed.
In Malaysia , Noraite SA-1 has been used in construction of aprons and floor screeding works. Noraite SA-1 has been tested to work with our Portable Foam Generator .
................................................ ............................................................
2. Noraite PA-1 is a protein based foaming agent suitable for making foamed concrete in the lower density range (eg. 800 kg/m3). Its dilution rate is about 1 part chemical to 33 part water and gives roughly 430 liters of foam from 1 liter foam agent.
Noraite PA-1 has been tested with all Portafoam models especially Model TM2 and PM-2 and conforms closely to the data mentioned.PA-1 produces foamed concrete which has relatively higher compressive strength than those using synthetic foam agents (e.g. SA-1 ).
Noraite foams however requires mixers which are dedicated specially to mixing foamed concrete such as spiral mixers & pan mixers.
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Agvantages
  1. Foamed Concrete (FC) blocks are lightweight and  can be easily produced according to different densities wherever it  is needed  ( factory or on- site ) therefore saving in transportation cost. Is a cement based product and compatible with jointing mortar / plastering other parts of the concrete structure.
  2. Due to its cellular structure, FC blocks has good heat insulation and high fire resistance. Buildings with FC blocks are much cooler compared to normal bricks.
  3. FC blocks also has a lower water absorbtion compared to other types of lightweight blocks , uses less plaster and can be used for external walls.
  4.  Sound insulation and absorbtion is good for FC Blocks especially if the are used as internal walls / partitions.
  5. FC blocks are light and just the right size so that construction and building rates are much faster. It is also more rigid and robust compared to other types of  lightweight blocks and suitable for high rise buildings.
  6. Less plastering and jointing mortar is used during construction ( since blocks are smoother & bigger than normal bricks ) providing a smoother wall finish at reasonable cost.



Foam concrete technology was developed in HBP - USM  as early as 1987. We have developed the technology to make foam generators, foaming chemicals, mixers, mix design & methods of producing good quality foamed concrete.
Our product range is mainly for small and medium scale production of foamed concrete although we do carry equipment for larger scale production.We have supplied equipment and know-how locally  and also to various other countries around the world. 
Below are photos and some description on the research and development made on foamed (cellular) lightweight concrete and related areas at the School of Housing , Building and Planning,  Universiti Sains Malaysia.
General Description
Foamed (or cellular) concrete is made from mixing preformed stable foam to a slurry of cement , sand & water. This action incorporates small enclosed air bubbles within the mortar thereby making the concrete lighter ( of lower density ). Foamed (cellular) concrete may have densities from as low 500 kg/m3 to 1800kg/m3 and strength from less than 1 N/mm2 to 25 N/mm2. It has a wide range of applications and some of them include wall blocks , wall panels , floor & roof screeds , trench reinstatement ,road foundations, bridge abutments and void filling.
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Photo at left shows the stable foam produced at HBP for making cellular concrete. The foam is one of the most important ingredients ("aggregate") in the making of this concrete. It must be stable and last through the initial stages of mixing the concrete. There are many types of foams (some proprietary) but protein foams are now being used more often in the production of foamed (cellular) concrete.
  Stable foam is the key ingredient in the production of foamed  concrete. This foam is made by a simple foaming generator  where air, water &foaming chemicals are mixed and stable foam is formed. This foam can be derived from either protein or synthetic chemicals. It consists basically of 95 % air and is very stable to enable it to last through the stages of mixing with the mortar slurry.
 The amount of foam expanded can affect the cost of the concrete being produced.  Generally , it takes about 400-500 liters of preformed foam to make 1m3 of foamed (cellular) concrete ( with a density range of 900 - 1300kg/m3).
Foaming Generator is used to generate stable foam for mixing with the sand & cement slurry to make cellular concrete. There various sizes of foam generators depending on the volume of foam concrete that is needed to be mixed. Foam chemicals also play an important role. Some foam chemicals do not produce the desired expansion of foam and are not stable in the concrete mix.
panelscast1.JPG (688812 bytes)                              
Timber forms  used to cast small panels of lightweight foamed (cellular) concrete for a bungalow project in Penang.On the right are blocks cast in steel molds. Although this may be slower, the surfaces are much better than normal bricks
One of the characteristics of foamed (cellular) concrete is its ability to flow and would require forms made of timber or steel to cast the required unit (e.g. block or panel). For void filling or trench reinstatement , the flowing characteristic of cellular concrete is important because no compaction involved (non-compacting concrete) after the concrete is poured.
                           
Picture above is foamed (cellular) concrete being poured to make blocks in steel molds
Larger panels can also be cast out of foamed (cellular) concrete but may need slight mesh reinforcement  to prevent shrinkage cracking and provide some strength during lifting. Although its weight is reduced , the large pre-cast panels still cannot be handled by one person and will require a light lifting device.
Foamed concrete can also be used as insulation screed on flat roofs. The insulation provided by this material is much better than normal mortar screeds and you also get a reduction in weight imposed on the roof structure. A density from 900 to 1200 kg/m3 can be used on roof tops for effective insulation.
Mixing just cement + water and foam will give you cellular cement. Cellular cement can have lower densities (400 - 700 kg/m3) but their strength is lower than foamed (cellular) concrete and can only be used for insulation (e.g. roof screeds) or void filling applications.
Stable foam can be incorporated easily into concrete masonry to improve its workability and handling. In addition to this one would also get masonry which is more fire resistant and better thermal characteristics.
Foamed (cellular) concrete is considered an environment  friendly material since it only uses sand & cement (no large aggregates) and 1m3 of raw materials can give nearly 2 m3 of concrete . This makes it a potential material in housing construction because houses can be built more quickly and cheaply with such lightweight material .   
Research on foamed or cellular concrete at HBP has been going on since 1987 and we have mixed various types of foam concrete including those with fibers, fly ash, rice husk ash, accelerators and plasticizers. We also have developed the technology to pour foam concrete into deep forms (e.g. cast-insitu walls) which is a normally difficult procedure.  
Part of our research activity also involves testing chemical foaming agents and experimenting on high strength foam concrete. We have developed and tested formulas which will allow the casting of structural beams and columns ( see main page) made of lightweight foam concrete. We are also strongly pioneering in this country, the use of foam concrete in geotechnical applications and utility trenches (Trench Reinstatement).   
      Most importantly we have managed to develop the technology for producing foam concrete tailored for small & medium scale production. One of our most prominent item is the Portable Foam Generator ( Portafoam TM for small to medium scale production of foam concrete which is portable and cost effective . Portafoam will allow  the normal builder to enjoy the benefits of making foam concrete as they wish without any hindrance from requirements such as exorbitant equipment costs or licensing.
 Producing foamed concrete does not require expensive & complex equipment and is a fairly easy process with a low initial capitaloutlay. More people are discovering the benefits of this innovative material and its many areas of usage within the building industry.



As many of us are aware , utility companies always dig our roads to install their pipes & cables for the purpose of providing services such as electricity and water.
Well after digging , these trenches have to be closed properly  for the comfort and safety of road users. In the event that these trenches are not reinstated properly , settlement of parts of the road can happen and this would eventually lead to accidents .
The standard procedure of trench reinstatement is to bury the pipes/cables underneath a layer of sand and subsequently the road proper (base & wearing course).
With the help of a local utility company here , we were given permission to try out foamed concrete in replacing the layer of sand above the cable. The total depth of the trench including the road base & surfacing is about 1m. Since this is a federal road , the depth of base course ( crusher run ) is 12" and surfacing is 4". There is a sand layer/ bedding of about 3" below cable and another 3" above it. A pvc plate is placed on top of this layer as a bond breaker between the concrete & cable.
This leaves us about 17" of foamed concrete to be filled. The width of the trench is about 16". The length of fill is 3m of full replacement (17") and another 3m of partial replacement(8") using foamed concrete.
Foaming Agents
The type of foaming agent used is  called FF - Foam . FF-Foam is one of the best synthetic foaming chemicals that we have tested. It has a rich creamy texture with fine sized bubbles. It is very stable and is sutable for using with ready-mixed concrete trucks.
Foaming Machine
The foaming machine was of the high capacity capacity type capable of producing about 5000 liters of foam in a single fill. This foaming machine is suitable for large scale production of foamed concrete on site and also in a factory. The amount of foamed cocnrete obtained during the trial mix was about 4 cubic meter. The foaming machine was transported to the ready mixed plant where the batching of raw materials was made.
Raw Materials
A mixture of fine sand & cement was first mixed dry in the ratio of 1(cement) : 1.5 part sand . A rich mix was chosen because of the early strength that was needed and the importance of protection of the power cables from moisture . Water was slowly added to this until a ratio of about 0.45 (w/c water: cement) to form a slurry of mortar. The stable foam was added to the slurry until a wet density of 1300 kg/m3 was reached.
Results - level measurements have shown that there have been no noticeable settlements on the roadside where the foam concrete is poured.

.DECORATIVE LIGTWEIGHT  FOAMED CONCRETE

  
DECORATIVE FOR AN AIRPORT PROJECT IN MALAYSIA
TECHNOLOGY FROM PORTAFOAM SYSTEMS


DRN RESOURCES  
"BUILDING SYSTEMS SPECIALISTS" 
                  
         “Technology for Lightweight Concrete , Foamed Concrete, Cellular Concrete

                                 Portafoam  ® Foam Generators and Mixers

                         Noraite ®  Foaming  Agents  and Additives



We are a Malaysian company specialized in providing  technology for the production of foamed concrete which includes equipment, chemicals and training.

We  also provide total solutions in building technology using lightweight foamed concrete

We have been in operation for more than 11 years and our achievements include the setting of 10 foamed concrete plants in Malaysia alone and have been involved in cast in-situ and geotechnical works using foamed concrete.

Besides this we have also supplied numerous companies abroad for production of foamed concrete.

Our Services :


Below are some of our latest projects ; 


     
United Engineers Malaysia headquarters building ( Floor Screeding ) 


250 Units Cast Insitu Portafoam Concrete Low Cost Housing 
for Trengganu (Malaysia) State Government Project

One of our 10 block plants in Malaysia using our technology, belonging to a state development corporation.


PORTAFOAM LIGHTCRETE

PORTAFOAM-LIGHTCRETE BUILDING SYSTEMS & APPLICATIONS


  
Important Notice

This is to inform readers that our previous website www.portafoam.com is under maintenance.

PORTAFOAM LIGHTCRETE

 Foamed (or cellular) concrete is a type of lightweight concrete made from mixing preformed stable foam into a slurry of cement, sand and water. The stable foam is simply made by mixing air and foaming chemicals in a foam generator.
Foam generators :
PM-1 .......... 150 lit / min foam
PM-2 ..........   250 lit/min foam
Best used with Noraite PA-1 foaming agent



THE PORTAFOAM BUILDING SYSTEM USES ELEMENTS OF LIGHTWEIGHT CELLULAR CONCRETE FOR AN INDUSTRALISED APPROACH IN BUILDING





PORTAFOAM LIGHTCRETE

 Foamed (or cellular) concrete is a type of lightweight concrete made from mixing preformed stable foam into a slurry of cement, sand and water. The stable foam is simply made by mixing air and foaming chemicals in a foam generator.
Foam generators :
PM-1 .......... 150 lit / min foam
PM-2 ..........   250 lit/min foam

Best used with Noraite PA-1 foaming agent
Contact:      sarahn@streamyx.com for production line





Foamed Concrete for Floor Topping.

Foamed (or cellular) concrete is a type of lightweight concrete made from mixing preformed stable foam into slurry of cement, fine sand and water.

The preformed stable foam is simply made by mixing air and foaming chemicals in a foam generator.

The hardened material consists of small enclosed air bubbles thereby resulting in a lightweight stable cellular material with densities ranging from as low as 500 kg/m3 to 1600 kg/m3.

Because of its varied density, foamed concrete has a wide range of applications ranging from wall blocks and panels, architectural decorative components, landscaping components, insulating roof screeds, trench and reinstatement, road foundations, and void filling.

One of the most popular use of foamed concrete in building construction is as floor topping on structural slabs. Due to its low density and cellular structure, foamed concrete has very good thermal insulation and fire protection qualities and reduces the overall weight of the floor. A 1000 kg/m3 foamed concrete may have more than 50% air content lowering its thermal conductivity thus reducing heat transmission significantly through the floor. Foamed concrete has lower thermal conductivity than normal concrete and makes it an ideal insulating material.

General thermal conductivity of cellular concrete compared to normal concrete

Bulk density ( kg/m3)
Thermal conductivity ( W / m deg C )
1,000
0.30
1,100
0.34
1,200
0.38
2,400 ( normal concrete )
1.83

The table above shows that thermal conductivity of cellular concrete at 1,000 kg/m3  is only 18% that of normal concrete.



In addition foamed concrete is basically an inert non-combustible material unlike many other types of insulation which may degrade over time or burn toxic fumes in case of fire.

Another advantage of using foamed (or cellular) concrete as floor or roof insulation topping is the ease at which the material can be laid. This is because of its high flow characteristics which require no compaction since the material is self leveling. This also means that the material can be carried and laid to any floor by light lifting equipment or pumped into place.

Due to the fact that thermal insulation is related to moisture content, it is better if the top of the placed ( or hardened) foam concrete is surface protected by a light expandable screed. This will ensure adequate protection not only to the underlying slab but also to the insulating layer of foamed concrete.



Text Box: Foamed concrete (Portafoam System) easily placed on a concrete floor slab for insulation and raising the floor level (Project: Kuching International Airport – Sarawak ).  



Foamed concrete can also be mixed with other suitable waterproofing agents to make it more impervious. In addition a layer of waterproof membrane in the form of a polymer modified mortar can also be applied on the finished foam concrete surface as protection. Foamed concrete can also be used in combination with polystyrene slabs where additional thermal insulation is required in very hot weather.



Text Box: Hardened foamed concrete insulation layer can be subjected to light traffic after 24hrs  ( image -foreground ). Any   further protective layer / coating or screed can be carried out within 20 hrs Compressive strength of  foamed concrete reaches 70% in just 7 days and increases in strength up to 91 days.


Foamed concrete is a economical and versatile insulation material to work with and can be produced and placed easily on any substrate including concrete slabs. It is the insulation material of the future for innovative contractors and builders.


Specifications for Insulation :

Density range : 500 – 1200 kg/m3   

Strength @ 28 days – 0.5 – 3.5  N/mm2 

Placement – by gravity or pump onto substrate.

Notes :  A layer of waterproofing membrane can be laid first before foamed concrete is being poured if the substrate is to kept dry. Another layer of screed compatible with foamed concrete or a flexible coating can be applied to the top of the foamed concrete after it has hardened.Otherwise tiles can be laid direct.





BASIC TRAINING


Training And Technology Assistance For The Production Of Foamed Concrete Basic Training Content :


1. Portafoam components and concept of Portafoam technology.
2. Basic Connections, Controls & Setting up Portafoam machine
3. Foam Properties & Adjustments
4. Foam Generation (Filling & operation, Cleaning & Shutting Down
5. Flow Rates & Quality of foam ( foam stability ).
6. Overcoming malfunctions of foaming system.
7. Basic properties of raw materials for foam concrete. 8. Mix design of foam concrete (normal mix) using USM empirical method.
9. Quality Control (water content, foam flow and density, wet & dry density )
10. Placing and Curing of foam concrete .


A Basic Training Manual shall be provided.
Duration 1-1/2 day at UNIVERSITI SAINS MALAYSIA , Penang.
Cost : upon inquiry
CONTACT -sarahn@stremyx.com or dr.norizal@drn.com.my 


Advanced  Training


PART II ( Advanced Production of Foamed Concrete )

1. Properties of raw materials and other additives for lightweight foam concrete blocks.
 2. Detailed mix design, proportioning and trial mixing ( mix optimization, alternative material ratios using locally available materials) for foamed concrete block production.
3. Using Excel Program for mix design and optimization of foamed concrete mix
 4. Batching methods, procedures and timing of mix for block production.
5. Chemical premix dosing system and procedures.
6. Mixer components, Mixing procedures and timing of mix for dedicated mixers (LN Series ).
 7. General large volume mixing and Quality Control procedures (eg. batching, w/c ratio, control of density, mixing time, air supply and foam quantity).
8. Foaming procedures and timing for large volume mix ( using PM2 Advanced system with auto chemical dosing )
 9. Placement of foamed concrete for block making
10. Mold Systems, De molding and preparation and layout of molds for block making.
11. Sequence and timing of placement for block making.
12. Curing method and regimes for specific product.
13. Lifting, placing and packing of dry components
14. Method of fixing and finishing to foam concrete blocks ( coatings, jointing mortars & plasters) for specific product. 15. Testing of dry components ( cube tests and in-situ test )
16. Other ancillary equipment needed for foam concrete production such as rails, forklifts, loaders or pumps if needed. Advice on land area, curing regimes and cost saving aspects of making foamed concrete.
 17. Coating / Finishing systems for foamed concrete
18. Jointing Mortars & Methods
19. Consultancy on other tests such as fire and sound insulation / or for approval by local authorities 





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