WO2010118744A1

WO2010118744A1 - Insulating high strength concrete material

Info

Publication number: WO2010118744A1
Application number: PCT/DK2009/050090
Authority: WO
Inventors: Kim Jørgen Schultz KIRKEGAARD
Original assignee: K-Consult
Priority date: 2009-04-17
Filing date: 2009-04-17
Publication date: 2010-10-21

Abstract

The invention relates to a high strength concrete, preferably an ultra high strength concrete having insulating properties. The insulating properties may be obtained by the inclusion of supplementary bodies made of an inorganic material such as glass-spheres, expanded clay aggregate such as Leca®, nano-tubes and other inorganic materials, or by the inclusion of supplementary bodies made of a polymeric material such as expandable polystyrene (EPS), polyurethane (PUR), foamed polypropylene (PP) or other foamed insulation material.

Description

INSULATING HIGH STRENGTH CONCRETE MATERIAL

The present invention relates to high strength concrete materials.

BACKGROUND OF THE INVENTION

WO2004/022503 discloses concrete containing polyurethane is provided and construction elements comprising such concrete. Methods for the preparation of polyurethane for inclusion in such concrete and for the formation of construction elements comprising such concrete are also provided. The strength and insulating properties of the concrete is not disclosed.

US 5,422,051 discloses cementitious concrete made from recycled plastics, Portland cement, and sand/gravel fillers performs to standards of concretes made without plastics. Heterogeneous plastic materials may be used in this concrete, removing the previously time and resource intensive step of sorting and melting down constituent plastics from each other in the waste stream. No insulating properties are disclosed.

WO96/30315 discloses insulating mortar which displays very good heat-insulating properties. It contains at least 70 vol. %, preferably at least 80 vol. %, in particular at least 85 vol. %, recycled, comminuted hard polyurethane, the remainder consisting of cement and optionally additives as well as water for setting purposes. No strength properties are mentioned.

SUMMARY OF THE INVENTION

The significance of this invention is the blend of high strength concrete materials such as the materials manufactured by the company Densit ApS of Denmark with various types of insulating materials that demonstrate similar or improved material properties compared to typical concrete blends. In this respect, the concrete formulation is described as a cement-based material comprising a coherent matrix, the matrix comprising

A) homogeneously arranged inorganic solid particles of a size of from about 50 A to about 0.5 μ, or a coherent structure formed from such homogeneously arranged particles, and

B) densely packed solid particles having a size of the order of 0.5 - 100 μ and being at least one order of magnitude larger than the respective particles stated under A), or a coherent structure formed from such densely packed particles, the particles A or the coherent structure formed there-from being homogeneously distributed in the void volume between the particles B, and optionally

C) additional bodies which have at least one dimension which is at least one order of magnitude larger than the particles A.

The typical high strength concrete materials such as materials from Densit ApS can be formulated with a number of different additives in order to achieve significant strength improvements over traditional concrete formulations. By adding insulating materials to high strength concrete materials such as Densit® ultra high strength concrete materials significant insulating properties can be achieved and still achieve mechanical properties similar to typical concrete formulations, however with significant insulating properties as well as weight and price reductions

High strength concrete materials such as Densit® ultra high strength concrete materials are mostly used for applications related to floor, pavement as well as offshore applications where extreme strength and mechanical properties out perform the usual use of concrete formulations. Due to these properties materials such as Densit® ultra high strength concrete materials have gained a significant marketplace with-in its typical applications.

The material according to the invention opens a whole new range of products and applications where the material blended with different insulating materials can be applied to present concrete applications without significant changes of the present concrete properties and added insulation properties. The material according to the invention has several application platforms where significant achievements can be reached. The achievements are all related to the combination of insulation performance along with structural and physical strength of the material. The following platforms are:

1. Insulation of offshore pipelines in order to ensure flow assurance

2. Insulation of onshore pipelines in order to ensure terrorism protection

3. Insulation of pipes in general

4. Structural and insulation flooring and wall applications 5. High strength lightweight structural elements

6. Fire protection

7. Meltdown protection on structural metal elements

The basis of all the applications are the formulation of high strength concrete such as the materials provided by the company Densit ApS of Denmark and blended with the insulating materia!. The significance of insulating material is the size and insulation capability when the materials are imbedded into the high strength concrete material. The more of the insulating material, the less weight and the more the overall insulation capability of the total matrix can be achieved, as well as a reduction of the physical properties, especially the strength, however still comparable with concrete formulations. Another important feature is the possibility to adjust the density of the high strength concrete with insulating material to exactly to the needed in relation to the other desired properties

Concrete matrices with added insulating materials are not typical seen applicable in the market due to lack of comparable performance related to other insulation concepts, like foamed polyurethane (PUR) for district heating pipes, mineral wool for building applications and industrial insulation concepts.

Recently protein foaming materials have been added to concrete formulations achieving insulation properties, however these materials typical applies to concrete. These protein materials are not applicable to high strength concrete materials such as Densit® ultra high strength concrete materials, due to non compatible blending between the different additives from these protein materials and the additives used for the high strength concrete materials such as Densit® ultra high strength concrete materials, and thereby not improving the mechanical properties. Concrete blended with these protein materials, even though some insulation properties is achieved, does not at the same time having significant structural properties related to the different applications identified above.

The major advantage of the present invention is the fact that two different types of bonding, determined by the nature of the insulating material, is clearly seen effective between the added insulating materials and the high strength concrete materials such as the Densit® ultra high strength concrete materials.

The effect of this being insulating materials made from materials comparable to concrete (like minerals) and insulating materials made from polymeric materials as group.

Choosing insulating materials comparable to concrete and high strength concrete materials such as Densit® ultra high strength concrete materials will have the ability to interface on a molecular basic and therefore the insulating material it self makes a contribution to the achievable strength that thereby forms a strong matrix that outperforms typical concrete blends and further have substantial improved insulation properties. Typical materials could be glass-spheres, Leca®, nano-tubes and other inorganic materials

The significance of the bonding of the other "type" of insulating materials, based on polymeric materials, are more related to the in capsulation of the insulating particle into the high strength concrete material such as the Densit® ultra high strength concrete materials, where the insulating material itself does not make a contribution of strength, however being blended with the right particle size and volume the high strength concrete materials such as Densit® ultra high strength concrete materials can be engineered and tailored to the specific application mentioned earlier. Typical polymeric materials could be EPS, PUR, foamed PP or other foamed insulating material.

Another significant advantage is the fact that even if highly combustible insulating materials, are embedded into the high strength concrete material such as the Densit® ultra high strength concrete materials, the blend performs with the highest fire ratings possible, due to the encapsulation of the non-flammable or flammable insulating material into the non-flammable high strength concrete material such as the Densit® ultra high strength concrete materials. This allows the composition according to the invention to be applied or sprayed onto surfaces that needs to retain an inflammable and at the same time, due to its insulating properties, delays melting of possibly metallic structural elements to which the composition according to the invention is applied and thereby the metal structural elements can retrieve its physical properties for a longer period of time.

A major advantage is also present for the composition according to the invention, when applied to sub-sea-level pipelines. Insulation of pipelines can be provided for one or more different reasons:

1) Insulation of offshore pipelines in order to ensure a certain flow rate 2) Insulation of onshore pipelines in order to ensure terrorism protection 3) Insulation of pipelines in general, e.g. for ensuring a certain temperature.

The significance of offshore pipelines is the nature of the fluid that is to flow inside the pipeline. Waxing and other fluid components need to remain above a certain temperature throughout the length of the pipeline to prevent clocking of the pipeline. The essential parameters for offshore pipelines are governed by the needed insulation in order to assure that the fluid being carried, maintains its properties until further processing is feasible. At the same time the size of the pipe diameter and the water depth determines the weight of the coating necessary in order to maintain the necessary buoyancy and weight that will keep the pipeline in position on the bottom of the sea. Three insulation concepts are typical used for the present offshore pipelines:

1) Pipe in pipe for laying at depths more than 200 meters 2) Single pipe for laying at depths more than meter 200 meters 3) Single pipe for laying at depths less than 200 meters

Other parameters are the feasible laying method of the pipes and which is determined by the total weight and the outer diameters of the pipeline, as well as the type of insulation method used for the pipeline. Usually the deeper the pipeline has to be laid, the higher the outer pressure, and several parameters have to incorporated into the total evaluation of the best fit for the complete installation of the pipeline. The feasibility study including price issues are deeply depending on the laying method. Four typical laying methods are identified as:

1) J-lay

The principle of the laying method applies to deep sea pipelines laid on water depths deeper than typical 500-1500 meters with a laying speed of 1 to 3 km/day

2) S-lay

The principle of the laying method applies typical to pipelines laid down to 0-1500 meter with a laying speed between 5 and 7 km/day depending on which of the 3 insulation concepts being used

3) Reeling

The principle of the laying method applies to pipelines laid on all water depths, however not all types of insulation concepts are that well suited for this method, as the strength of the insulation determines the suitability

4) Towing

The principle of the laying method is applied after the pipeline have been welded and joined on shore, the pipeline is towed to the site and lowered to its potion on the sea.

Single pipes are described as pre-insulated pipes for district heating, comprising of a medium conveying pipe, an insulating material surrounding at least a part of the length of the medium conveying pipe and a jacket pipe at least partly surrounding the insulating material. In the alternative, the single pipe may be provided with an insulating material surrounding at least a part of the length of the medium conveying pipe, but without a jacket pipe surrounding the insulating material.

Such pre-insulated pipes are mostly used for any media at a temperature between -200⁰C and +315°C in order to provide insulation of different media when applied on-shore. However for e.g. for single-user offshore pipelines in order to ensure flow assurance the media temperature is usually restricted to an application temperature between -48°C and +160⁰C depending on the water depth and the required insulation thickness .

During the years much effort has been done in designing new pre-insulated pipes having increased initial as well as long term insulation properties, and at the same time keeping the production, laying and material costs at a low level in order to provide the lowest possible operating costs for the owner of the flow line system.

Therefore an object of the present invention may also be to provide a pre- insulated pipe of the kind mentioned above, simplified by having sufficient insulation properties and at the same time having the sufficient weight to perform as a weight coating.

With the present invention, a one layer solution not only provides an impermeable insulation coating it also provides simplified joint solutions as well as insulation properties independent of the water depth as the impact from the outer pressure is related to the high strength concrete material such as Densit® ultra high strength concrete materials and not the polymeric matrix usually being the designing parameter for pre-insulated pipes according to the described single pipe system. As no temperature dependant shrinkage occurs to the insulation concept according to the invention long term insulation properties are thereby maintained as no creep and hysteresis phenomenon occurs.

The object is obtained by the pre-insulated pipe, where the pipe is characterized in that it comprises a layer of polymeric material blended with high strength concrete material such as Densit® ultra high strength concrete materials, at least partly surrounding the flow line being permeable to water or water vapour, and having significantly better barrier properties than PE, for resistance against diffusion of oxygen and carbon dioxide.

When producing district heating pipes it is very common to use foaming agents such as cyclopentane for producing of polymeric foam from e.g. polyurethane and styrene foam. In the finished foam the cell gas composition will contain a significant amount of carbon dioxide and pentane, where the carbon dioxide is primarily generated during the foaming reaction process.

By the present invention it is thereby obtained that water vapour is not allowed to penetrate into the insulating material, as well as the high strength concrete material such as Densit® ultra high strength concrete materials will prevent that carbon dioxide or other cell gas compositions will exchange with the ambient oxygen to build up in the insulating material.

The effect of the present invention will be significantly advantageous if the layer of polymeric material or mineral insulating material has a resistance against diffusion of oxygen and carbon dioxide being better than perhaps 5 times and preferably 10 times the same resistance for a similar layer of concrete comparable with the water vapour resistance of PE, being measured according to any accepted test methods such as ASTM F-1249-90 : 38⁰C, 90%RF, ASTM D-3985-81, 23°C, 0%RF and DIN 53380 part 1 1982, 23°C, 0%RF.

With the present invention, a one layer solution not only provides an impermeable insulation coating, it also provides simplified joint solutions as well as insulation properties independent of the water depth as the impact from the outer pressure is related to the high strength concrete material such as Densit® ultra high strength concrete materials. The nature of the mineral material such as ceramic spheres, glass bubbles, Leca or other spheres improves the mechanical stability and strength of the high strength concrete materia! such as Densit® ultra high strength concrete materials.

The crushing strength of such Densit® ultra high strength concrete blends easily reaches a level of 20 to 50 MPa depending of the blend which enhances the application parameters for deep-sea pipe laying enabling the tailored insulation blend of which the polymeric matrix usually being the designing parameter for the strength, the weight and/or the insulating properties. Similar application parameters is just as valid as for blend not only comply with the required insulation, but also tailored to have the right density to accommodate necessary weight coating. High strength concrete material blends such as Densit® ultra high strength concrete materials blend with polymeric insulating materials offers similar properties.

These features are obtained by the pre-insulated pipe according to the invention, where the pipe is characterized as a layer of material according to claim 1 at least partly surrounding the coating of the flow-line, having the suitable bonding strength to the typical FBE (Fusion Bonded Epoxy) or other coating material enabling the complete insulation structure to be integrated with the pipeline material. Further the insulating material according to the invention, provide a layer of material being permeable to water or water vapour, and having significantly better barrier properties than PE, for resistance against diffusion of oxygen and carbon dioxide.

The invention may be tailored with respect to different blend criteria of the needed application parameters of which the single insulation layer is applied.

These criteria would or could be:

1. Insulation capability related to needed strength 2. Needed insulation related to the needed weight

3. Needed strength related to applicable water depth

4. Needed flexibility during pipe laying related to the above parameters

All the above criteria should or could, but need not, also be related to price.

Another effect of the invention is that the sensitivity to cracks is very low in the outer insulation layer during bending the flow line during pipe lay, and does not cause any hazard to the insulation as the insulating material is embedded in the high strength concrete material such as Densit® ultra high strength concrete materials and is thereby unaffected by the water filled environment created during cracking condition. When the pipe is straightening out on the bottom of the sea the magnitude of the cracks is insignificant as the cracks are expected to close when the pipeline is straighten out.

Claims

1. A cement-based material comprising a coherent matrix, the matrix comprising

B) densely packed solid particles having a size of the order of 0.5 - 100 μ and being at least one order of magnitude larger than the respective particles stated under A), - or a coherent structure formed from such densely packed particles, the particles A or the coherent structure formed there-from being homogeneously distributed in the void volume between the particles B,

C) additional bodies which have at least one dimension which is at least one order of magnitude larger than the particles A, D) supplementary bodies having insulating properties which is at least one order of magnitude greater than the particles C.

2. A material according to claim 1, where said supplementary bodies having an outer diameter less than 3 mm, preferably less than 100 microns and a surface area of less than 10,000 m²/kg, possibly less than 7,000 m²/kg, preferably less than 3,000 m²/kg.

3. A material according to claim 1 or claim 2, said material having an insulation capability being less than 400 rmW/mK (0-100⁰C) preferably less than 200mW/mK (50°C)

4. A material according to any of the preceding claims, said material having a crushing strength of minimum 1.5 MPa.

5. A material according to any of the preceding claims, said material being mixed with polymeric materials, having an outer diameter less than 6 mm material, preferably less than 1,5 mm and a surface area of less than 100 m²/kg.

6. A material according to claim 5, said material having an insulation capability being less than 150 mW/mK (0-100⁰C) preferably less than 75mW/mK (50⁰C).

7. A material according to claim 5 or claim 6, said material having a crushing strength of minimum 0.05 MPa.

8. A material according to any of the preceding claims, where the supplementary bodies are solid structures or are voids within the material.

9. A material according to any of the preceding claims, where the supplementary bodies D) are coherent with at least one of the particles A), B) or C) of the concrete material by physical bonding and/or by chemical bonding,

10. A material according to any of the preceding claims, where the supplementary bodies are made of an inorganic material such as glass-spheres, expanded clay aggregate such as Leca®, nano-tubes and other inorganic materials, or where the supplementary bodies are made of a polymeric material such as expandable polystyrene (EPS), polyurethane (PUR), foamed polypropylene (PP) or other foamed insulation material.