Improving the performance of asphalt and cement based composites by utilising waste GRP powder as filler material

Abstract

The invention relates to the use of glass fibre reinforced (GRP) composite pipe waste as filler material in both asphalt concrete and cement based composites. Significant ecological and product performance benefits are provided by using the material produced during the cutting and production processes of GRP pipes in mixtures as filler material by wet or drying and sieving through sieves of desired sizes.

Description

[0001] IMPROVING THE PERFORMANCE OF ASPHALT AND CEMENT BASED COMPOSITES BY UTILISING WASTE GRP POWDER AS FILLER MATERIAL

[0002] Technical Field

[0003] The present invention relates to the improvement of the performance of asphalt and cement based composites by the addition of waste glass fibre reinforced polymer (GRP) powder to asphalt and cement based composites, in particular by the use of waste GRP powder as filler material.

[0004] Prior Art

[0005] Due to their high corrosion, heat resistance and high strength properties, GRP pipes, which are widely preferred for underwater and underground transport of liquid materials such as natural gas, petroleum, thermal water, wastewater, and even drinking water, generate a large amount of waste material during cutting for production and joining processes.

[0006] Bitumen is an organic, highly viscous, non-volatile, sticky and waterproof material. Bitumen, which is derived from crude oil or used in natural asphalt concrete, is a petrochemical product and its optimum use comes to the fore due to economic concerns. The presence of a filler is essential to ensure adequate stability during transport and placement of asphalt concrete and to prevent drainage of the binder. Similarly, self-compacting concretes and ultra-high performance concretes, which have been introduced into our lives in the last 20 years with their super features such as high strength and durability, are characterised by a high mortar phase. The performance of the mortar phase in these composites positively affects the physical, mechanical and durability performance as well as the rheological properties of the composite. For this reason, it is preferred to use powdered filler materials below 1 mm (mostly below 600 microns or 125 microns) in the mixtures. In this direction, it is a popular method to obtain filler materials that have waste potential and contribute to the expected performance of the related composites, especially from waste materials. In this direction, pozzolanic and mineral additives such as fly ash, blast furnace slag, silica fume, recycled concrete aggregate, brick powder, waste marble powder, waste ceramic powder, etc. are widely used. However, significant environmental impacts may occur during the production of these admixtures. In the document titled “CTP Boru Uretim Atigi Ilaveli PVC Matriksli Kompozit Malzemelerin Mekanik Ozelliklerinin Incelenmesi” [AKINCI, A., OZUYAGLI, A., MEHMET ALiOGLU, C., & OZSOY, M. (2016). Gazi Universitesi Miihendislik Mimarlik Fakiiltesi Dergisi, 31(2)], industrial waste generated during wet cutting is used in the production of glass fibre reinforced polyester pipes. The waste contains silicon dioxide (SiCh), glass fibre and polyester resin. The waste, which came out of the filter press in the form of slurry, was taken from the factory and after drying, grinding and sieving processes were applied and brought into powder form. The samples were produced in the form of profiles by extrusion method by mixing PVC, GRP waste powder and process auxiliary materials in a mixer. The waste powder was used as filler material for PVC at a ratio of 5- 70% by weight. Higher stiffness, flexural strength and tensile strength values were obtained by using GRP waste powder filler instead of calcium carbonate filler traditionally used in PVC production.

[0007] The document numbered CN108585622A discloses a method of preparing asphalt road surface material modified with waste glass fibre reinforced plastic. The method of preparing the waste glass fibre reinforced plastic modified asphalt road surface material comprises placing the preheated matrix asphalt and the preheated waste glass fibre reinforced plastic powder into a heated first mixer for mixing to obtain glass fibre reinforced plastic modified asphalt, the process steps of adding preheated and evenly mixed aggregates and preheated glass fibre reinforced plastic modified asphalt to a second mixer for mixing, adding preheated waste glass fibre reinforced plastic powder and preheated mineral powder to the second mixer for mixing to obtain waste glass fibre reinforced plastic modified asphalt road surface material.

[0008] It is stated in said document that the asphalt road surface material modified with waste glass fibre reinforced plastic and the method of preparation of the asphalt road surface material modified with waste glass fibre reinforced plastic enable the reuse of waste glass fibre reinforced plastics, thereby saving resources and reusing solid waste. Waste glass fibre reinforced plastic powder consists of a thermoset epoxy resin and glass fibre. It is stated that said plastic powder consisting of epoxy resin and glass fibre is 6% and 3% in the third and fourth samples, respectively.

[0009] The document numbered CN104861676A relates to an asphalt mix additive based on waste super polymer, the method of preparation and application thereof. The additive comprises 30-60 parts waste / reclaimed polyethylene particles, 20-50 parts waste tyre rubber powder, 10-20 parts SBS, 5-15 parts fibre and 0,5-1, 5 parts carbon black. The fibre and carbon black form a filler. The fibre is selected from basalt fibre, polymer fibre and lignin fibre.

[0010] Objects and Brief Description of the Invention

[0011] The object of the present invention is to provide a composite composition for microcrack bridging and ductility enhancement in cementitious composites such as asphalt concrete, self-compacting concrete and ultra-high performance concrete.

[0012] Another object of the present invention is to realise a composite composition which allows the use of waste GRPs as filler material in composites.

[0013] The powders from waste GRP pipes utilised within the scope of the invention can be used as fine-grained powder materials to improve the economic, ecological, physical, mechanical and durability properties of composites. These powders have advantages such as micro-crack bridging and ductility, which are desirable properties of cement-based composites such as asphalt concrete, self-compacting concrete and ultra-high performance concrete, due to the micro-milled glass fibre in their content. In the invention, waste GRP powders can be used as filler material in self-compacting concrete and ultra-high performance concrete at a maximum rate of 15% and 25% by weight, respectively, and in asphalt concrete at a maximum rate of 5-30% by weight, and composite products with the required performances can be obtained. In order to contribute to the recycling of these wastes, by providing the opportunity to use them as performance-improving filler material in new composites with high added value, it will be ensured that the idle waste GRP powders will be regained to the economy and gain commercial value.

[0014] Detailed Description of the Invention

[0015] The composite realised to achieve the objects of the present invention is described by the attached figures.

[0016] Figure 1 Density plot of a fresh mortar containing cement doped with waste GRP powder according to the invention before curing.

[0017] Figure 2 Spread diameter plot of a fresh mortar containing cement doped with waste GRP powder according to the invention before curing. Figure 3 Porosity plot of a mortar containing cement doped with waste GRP powder according to the invention after curing.

[0018] Figure 4 Compressive strength plot of a mortar containing cement doped with waste GRP powder according to the invention after curing.

[0019] The inventive composite essentially comprises waste GRP powders, at least one binder and at least one aggregate. Within the scope of the invention, waste GRP powders with dimensions below 1 mm, preferably below 600 pm, in particular below 125 pm, are used.

[0020] A self-consolidating concrete according to the invention comprises cement, aggregate and other additives as binder and up to 15% by weight of waste GRP powder.

[0021] An ultra high performance concrete according to the invention, comprising cement, aggregate and other additives as binder and up to 25% by weight of waste GRP powder.

[0022] An asphalt concrete according to the invention comprises asphalt (bitumen) as binder, aggregate and other additives, as well as 5-30% by weight of waste GRP powder.

[0023] The composite according to the invention, essentially produced with the process steps, grinding GRP pipe waste into powder, sieving of waste GRP powder, mixing of sieved waste GRP powder with binder and aggregate, solidification of the mixture.

[0024] Solidification of the mixture can be carried out by curing in applications where the binder is cement and by cooling in applications where the binder is asphalt.

[0025] In this invention, GRP pipe waste is powdered and used as filler material in both asphalt concretes and cement based composites. The positive effects of waste GRP powder used as filler material on the rheological, physical, mechanical and durability properties of the composites were determined and contribution was made to the evaluation of waste GRP powder, which is an industrial waste, as a composite filler material with high added value. In asphalt and cement based conventional composites, natural resources such as stone dust, natural pozzolan dust, etc. are used from time to time in order to meet the powder material requirement, and this situation causes negativities such as ineffective management of natural resources in terms of environmental impacts. Aggregate and especially fine-grained materials used as filler materials are important for the physical and mechanical properties of asphalt concrete. The correct selection and optimum use of the filler material can contribute to the optimum use of bitumen used in asphalt concrete and contribute to the minimum use of bitumen, which is a petrochemical product, and both environmental and economic contributions are obtained. The use of filler material in high performance concrete production and self-compacting concretes, which have become widespread in recent years, contributes positively to both rheological and long-term mechanical strength, durability and performance properties of these composites. The use of the material produced during the cutting and production processes of GRP pipes in mixtures as filler material by wet or dried and sieved through sieves (<125 pm) offers significant contributions in terms of both ecological and product performance.

Claims

CLAIMS1. A composite comprising at least one binder and at least one aggregate and characterised by further comprising waste GRP (glass fibre reinforced polymer) powders.

2. A composite according to claim 1, which comprises cement as binder and is a selfcompacting concrete characterised by comprising at most 15% by weight of waste GRP powder.

3. A composite according to claim 1, which comprises cement as binder and is an ultra- high performance concrete, characterised by comprising at most 25% by weight of waste GRP powder.

4. A composite according to claim 1, which comprises asphalt (bitumen) as binder and is an asphalt concrete characterised by comprising 5-30% by weight of waste GRP powder.

5. A composite according to claim 1, characterised by comprising waste GRP powders having dimensions less than 1 mm.

6. A composite according to claim 5, characterised by comprising waste GRP powders having dimensions less than 600 pm.

7. A composite according to claim 6, characterised by comprising waste GRP powders having dimensions less than 125 pm.

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