An eco-friendly coir pith based cement composite and method of preparation thereof

Abstract

Present invention discloses about a formulation and natural method of treating of coir pith for coir pith based cementitious products. The waste grade coir pith is subjected to a controlled retting process for a duration of one month by immersing it in gently flowing water, with the temperature maintained between 23-35 degrees Celsius. Then treated coir pith is meticulously combined with Portland cement at a specific weight ratio, utilizing water as a binding agent, and placed within mould or die to attain the desired structural form. After a suitable duration of curing and drying, the product becomes ready for utilization specially for wood substitute. The application of additional pressure on the molds during formation can lead to heightened structural integrity and strength. Amount of raw materials in the proposed formulation are 10% -30% of treated coir pith, and 90% - 70% ordinary Portland cement, water and suitable additives.

Description

[0001] Description

[0002] Title of the invention

[0003] An eco-friendly coir pith based cement composite and method of preparation thereof

[0004] Technical Field

[0005] The invention relates to eco-friendly treatment method of coir pith for cement based products, especially invention relates treated waste grade coir pith preparation method for non-structural cement products.

[0006] Background art

[0007] Coconut coir pith (also known as coco peat, coir waste or coir dust) is short spongy fibers. In the extraction of coir fiber from the coconut husk and in the production of finished materials from the extracted fiber, a large amount of coir pith is produced. Coconut coir pith is described as that brown, spongy particle of low weight, which falls out when the fiber is shredded from the husk. The coir pith is about 70% of the weight of the coconut husk. It is rich in lignin and tannin and reported to be composed of cellulose, pentosan, furfural, and lignin. Whilst a great deal has already been learned about the solid parts of the coconut, coir pith has, up to now, the least use and is still considered waste and nuisance for which no important industrial uses have been developed, and they are normally incinerated or dumped without control. It is known to have no commercial importance except, may be, in applications where coirpith is used in a very limited amount. However, in an effort to find an immediate solution to the perennial problem of coir pith disposal, several product development activities were undertaken that may bring about large scale utilization of this waste material. As a major application, coir pith is used in the tropics as a locally available material for preparing soilless growing media for containerized crop production. During the past few years has this material become commercially popular and it is now being successfully used in different parts of the world as an environmentally sound peat substitute for container-grown ornamental plants. Additionally, coir pith is used as a soil conditioner. In the traditional process of coir fiber extraction, the husks are separated from the coconuts and soaked in lagoons or brackish waters for up to 10 months. While submerged, the husks undergo anaerobic fermentation, which causes them to soften and separate. Separated soften material facilitate grinding. After grinding of the husk, the long fibers are removed and used for various industrial purposes, such as rope and mat making. The remaining material, composed of pith tissue and short and medium length fibers, is commonly referred to as waste-grade coir. The waste grade coir may be screened to remove part or most of the fiber, and the remaining product is referred to as coir pith. Coir pith is predominantly composed of essential elements such as lignin, cellulose, hemicelluloses, and extractives like pectins and tannins. These components are rich in functional groups such as carboxyl, hydroxyl, and ether, imparting coir pith with valuable adsorption and ion exchange capabilities. The lignocellulose nature of coir pith is evidenced by its composition, including approximately 2-3% of short fibers and cork. Notably, coir pith boasts a substantial 31% lignin content and 27% cellulose content. Detailed chemical analysis reveals its constituent makeup as follows: Carbon 40.8%, Hydrogen 3.5%, Oxygen 40.3%, Nitrogen 0.2%, Sulfur 0.1%, and Ash 15.1% by weight (Narayana et al., 2010). The coir pith's higher lignin content contributes to its remarkable resistance to biological degradation. Displaying a typical density of 0.2 g cm-3, coir pith is amenable to substantial compression, reducing its volume by a factor of 8 to 10. This feature facilitates the creation of coir bricks, enhancing transportability and enabling efficient exportation.

[0008] Apart from its direct use as soilless media, coir pith is subjected to treatment to modify its chemical and physical properties for utilization as raw materials or filler material. An illustrative example involves chemically treating coir pith to enhance its durability within cementitious matrices and mitigate adverse impacts on cement hydration. Narendar et al. (2013) provide a comprehensive overview of treatment methods, including: Sodium hydroxide (NaOH) treatment: Coir pith is exposed to NaOH at room temperature for 1 hour, followed by a 2-hour drying period at 70°C; Dicumyl peroxide (DCP) treatment: Coir pith undergoes a 30-minute treatment with DCP in acetone at 30°C; Sodium hypochlorite (5% NaOCI) treatment: Coir pith is treated with a 5% NaOCI solution at 30°C for 4 hours; Acrylic acid treatment: Coir pith is exposed to a 1% acrylic acid solution at 70°C for 1 hour; Acetic acid treatment: Coir pith is treated with a solution containing a 10:1 ratio of acetic acid and acetic anhydride at 30°C for 1 hour; and Sulfuric acid treatment: Coir pith is subjected to a treatment with 64% weight of H2SO4 at 45°C for 180 minutes. These treatments contribute to the transformation of coir pith's properties, rendering it more suitable for specific applications, particularly in cementitious contexts. CN105948594 (A) also presents a technique for making robust, crackresistant cement mortar with higher strength using adapted coir fiber. The procedure initiated by cleansing the coir fiber, submerging it in a blend of KOH solution and H2O2, and subjecting it to heat treatment. Subsequent to this treatment, the coir fiber is meticulously rinsed, dried, and sheared, leading to the creation of the altered coir fiber. Dana et al. (2015) have also presented the utilization of coir pith as an additive within cementitious blends. The article highlights that concrete compositions containing 5% (by mass of cement) of coir pith exhibit favorable physical properties, rendering them suitable for structural applications. However, an increase to 10% coir pith content leads to a notable escalation in total porosity, subsequently causing a more rapid decline in material qualities, a deterioration that exceeds acceptable limits.

[0009] In their exploration of treatment methods, the study found that utilizing NaOH as a chemical agent for acetylation yielded comparatively more favorable results. Nevertheless, it is acknowledged that chemical-based treatment procedures present significant challenges and risks. They necessitate specialized equipment, skilled personnel, and in-depth expertise, thus incurring substantial expenses in terms of both capital and operational costs relative to the final product's value. Moreover, there are environmental implications throughout the manufacturing and usage phases. Given these considerations, it is common practice to prioritize chemical-free methodologies in pursuit of more cost-effective and environmentally sound alternatives. The RU2235082C1 patent introduces a novel approach for formulating reinforced foam concrete utilizing treated coir fiber (Not coir pith) as a foundational component. This lightweight concrete foam finds frequent application in insulating sandwich panels. To achieve optimal distribution within cement mortar, the chosen coir fiber possesses a length ranging from 5 to 30 cm and a diameter of 0.20 to 0.25 mm, endowing it with the necessary elasticity. Given the inherent instability of the elongated fibers, the inventors systematically reduced them into lengths of 1 to 10 mm and subjected them to a 24-hour water immersion to enhance their wetting properties. The concrete foam formulation process involves combining the treated coir fiber with sand featuring grain sizes between 0.1 and 0.5 mm. This mixture is augmented by the inclusion of a compatible foaming agent, ideally sourced from a range of cationic surfactants, presented in the form of 30 to 33 percent aqueous solutions.

[0010] Considering the cost and environmental concerns associated with sand as an additive, scholars are dedicating their efforts to explore alternatives for sand-free cementitious products. A pragmatic avenue for investigating the creation of sand-free cementitious coir products involves adopting the conventional retting process for coir fiber. This process entails transforming coconut husks into fiber through a soaking period of 6 to 10 months, yielding a distinctive high quality fiber. This approach aligns with the findings of Dhandhania et al. (2014), who also endorse the utilization of this method. In the retting process described by Dhandhania, coir pith, often considered waste, is discarded, thereby removing some impurities from the coconut husk. However, despite the success in obtaining high-quality fiber through this traditional route, a notable downside persists in the form of significant environmental waste generated. Technical Problem: The existing body of knowledge encompasses the introduction of coir fiber into cementitious mixtures, with various innovative methods and techniques documented worldwide. Coir fibers play a distinct role within cementitious materials, posing a unique challenge. The objective at hand is to devise an optimal procedure for producing a cementitious product with a substantial coir pith content (~30%) that is devoid of sand, devoid of chemical treatments, and ecologically sound. While references such as RU2235082C1, Dhana et al., and Dhandhania et al. have provided insights, they fall short of offering a comprehensive solution for this specific context. RU2235082C1 delineates a composition for forming concrete that incorporates merely 3% coir fiber through rapid retting. On the other hand, Dhandhania et al. thoroughly explores the conventional extended coir fiber retting process, albeit viewing coir pith as waste. Dhana et al., in their study of cementitious composites, discloses the utilization of raw coir pith up to 5% and chemically treated coir pith up to 10%. The challenge emerges as the current author seeks to formulate a strategy for achieving sand-free bricks with coir pith exceeding 30%, a task unaddressed by the aforementioned sources. A notable limitation arises from the modest thermal stability of these fibers, influenced by the degradation behavior intrinsic to cellulose-based fibers, shaped by their chemical structure. Alkaline treatment, aimed at enhancing fiber-matrix adhesion, has been hindered by resultant fiber strength reduction. The findings by Dana et al. indicate that 20% alkaline-treated coir fibers exhibit maximal shrinkage and weight loss. This phenomenon can be attributed to the substantial water absorption by high NaOH concentrations, causing fiber swelling. Subsequent elimination of water leads to structural shrinkage and weight loss. Research substantiates that chemical treatment is an unsuitable method for coir pith mixed cement composites. Furthermore, considering the physical and morphological attributes, coir pith is more susceptible to detrimental effects from alkaline treatment compared to coir fiber. Hence, prevalent treatment methods could potentially give rise to long-term functional concerns in coir pith / cement-based structures. This underscores the critical importance of identifying an appropriate treatment approach for coir pith in cement-based products before embarking on the development of non- structural items relying on coir pith mixed cement composites.

[0011] Technical Solution: The present invention introduces an economically efficient approach to cementitious product creation through the formulation of waste grade coir pith. This coir pith encompasses coir dust along with short and medium-sized coir fiber dust. Within the coir industry, post-husk grinding, coir pith accounts for about 70% of the coconut husk's weight, leaving behind substantial quantities of waste grade coir. This method capitalizes on the utilization of waste grade coir pith for non-structural cement composites, including applications like wood substitutes; interlock paving blocks, partition blocks, roofing and ceiling product range, fences, and building blocks.

[0012] The present invention discloses a novel application wherein treated coir pith is being embraced as a viable alternative to conventional sand usage. The findings elucidate that treated coir pith demonstrating it's potential to serve as a partial replacement for river sand. The utilization of treated coir pith within cementitious formulations prompts an exploration into prevalent chemical treatment techniques and their effects on the resultant cementitious structures. Notably, chemical treatment induces alterations in the surface morphology of coconut fiber, rendering it rougher in texture, albeit accompanied by a marginal reduction in mechanical strength.

[0013] While the incorporation of natural fibers into cement-based products is a known technique, conventional approaches entail using these natural fibers either in their raw state or chemically treated. However, both methodologies carry inherent limitations. The present invention offers an innovative, natural method to treat coir pith specifically tailored for sand-less non-structural cement-based products. In this approach, coir pith is integrated in the range of 10%-30% of the cement portion by weight. An increase in the proportion of waste grade coir is found to inversely impact the strength and durability of the resulting product. Coir pith uniquely contributes to reduced density and enhanced post-cracking behavior within the composites, making them suitable for crafting lightweight, non-structural building materials with commendable compressive strength and low bulk density. The inclusion of short and mediumsized coir fibers in coir pith amplifies the strength and durability of the resulting cement-based product.

[0014] The inherent lignin-rich composition of coir pith renders it resistant to biological degradation. Lignin serves as a multifunctional component, acting as a binder, filler, phenolic resin ingredient, and adhesive. The prolific utilization of this lignocellulosic waste material owes to its remarkable water absorption and retention properties. During the treatment process, the lignocellulosic bond within coir pith is disrupted, transforming it into adhesive dust. Furthermore, coir pith exhibits a remarkable water absorption capacity, further augmenting the strength and durability of coir pith-based cement products. The drying process reduces the propensity for cracking, making coir pith and cement composites ideal for moldable items. Enhanced strength can be attained by applying pressure during molding.

[0015] The method for preparing treated coir pith-based cement products involves several steps: Coir pith undergoes controlled retting for a duration of one month by immersing it in gently flowing water, with the temperature maintained between 23-35 degrees Celsius; blending coir pith with Portland cement and suitable additives in the correct ratio; molding the mixture, optionally with pressure applied on the mold; and allowing the cement-coir pith mixture to solidify. In this process, following the retting period, the coir pith undergoes a transformation in surface appearance, evolving into an adhesive dust with a discernible texture. This adhesive dust aids in bonding cementitious mixtures, requiring more water than conventional blends. Common cement mix additives can be incorporated. The optimal formulation for treated coir pith-based cement products encompasses a range of at least 10%-30% treated coir pith, 70%-90% ordinary Portland cement by weight, suitable additives, and sufficient water. Enhanced strength is achievable with a formulation comprising 20% treated waste grade coir pith, 80% ordinary Portland cement, appropriate additives, and adequate water. The same formulation, adapted as 20% treated coir pith, 80% ordinary Portland cement, 0% additives by weight, and ample water, is well-suited for interlock paving blocks.

[0016] Brief description of drawings

[0017] Figure 1 shows present product in the ceiling applications.

[0018] Figure 2 shows a present product at the architectural wall applications.

[0019] Advantageous effects

[0020] Availability; Coir dust is primarily produced in Sri Lanka, India, the Philippines, Indonesia, Mexico, Costa Rica, and Guyana. The Philippines reportedly is one of the largest producers of coconuts with >427 million trees. Sri Lanka produces =350,000 to 500,000 tons of new coir dust annually. Sri Lanka, with a coconut crop of over 3 billion nuts per year, has been engaged in the production of coir fiber and a wide range of coir fiber products.

[0021] Eliminating health hazard related with artificial fibers and chemical treating of natural fibers; This invention eliminates health hazard related with the existing artificial fibers. It also introduces natural fiber product with 100% natural treatment method. Existing chemical treatment methods for natural fibers can changed the surface morphology of coconut fiber to become rougher though its mechanical strength decreases slightly. These chemical treating methods have the major drawbacks of the limited thermal stability of these fibers, where this degradation behavior of cellulose-based fiber is greatly influenced by its chemical structure then finally strength of the end product. Solve a environmental burning problem; Coir waste is a biomass residue generating during the coir extraction of coir fiber from coconut husk. This coir waste has been disposal by the burning. This burning has resulted in various environmental problems. Coir pith is defined as an agrowaste produced during coir fiber extraction, constituting about 70% of coconut husk. This huge environmental impact can be eliminated with a value added product.

[0022] No additional unit operations for coir pith; Coir pith is retted in natural controlled conditions and there is no any unit operations added as retted coir pith is directly added to the portland cement mix. All coir dust and short and medium scale fibers are directly added to the cement mix.

[0023] Elimination of sand requirement for cement base coir pith products; The current demand for sand for building construction within the country is approximately 7- 7.5 million cubic meters per year in Sri Lanka. The Nilwala and Ginganga rivers are the main rivers in southern Sri Lanka that are suffering from both illegal and excessive sand mining. Present technology eliminated requirement of sand for cement base nonstructural material which saves environment.

[0024] Coir pith has special characteristics which suits for cementitious composites; Main characteristics of coir pith are its hydrophilic nature, absence of pathogens and renewability with no ecological drawbacks to its use due to its slow natural decomposition rate. Additionally, chemical composition of coir waste gives good water retention with slow degradation. Coir pith consists primarily of lignin cellulose, hemicelluloses and extractives, such as pectins and tannins, and the weight % content of lignin is high. These constituents primarily contain carboxyl, hydroxyl and ether groups, which makes coir pith a useful adsorbent or a natural ion exchange. Generally, the density of coir pith is typically 0.2gcm-3 .It contains higher proportions of cellulose besides potash and lignin and it has excellent moisture retaining capacity with slow in decomposition. It decomposes very slowly in the soil as its pentosan-lignin ratio is below 0.5 and because of the chemical and structural complexity of its I igni n-cel I u lose complex. coir pith based cementitious composites has specific characteristics for unique applications;

[0025] Using lignocelluloses fibers has advantages, such as their low specific mass, softness, reduced abrasiveness, non-toxicity, biodegradability, low cost and energy consumption in production, low thermal conductivity and good thermal and acoustic insulation. Additionally, these products are stronger than cellulose based product and will be cheaper in production compared to competitive products. Those are termite free, fireproof light weight Products can be easily manufactured and installed. Moreover, conventional cement products are characterized by a brittle behavior, with low tensile strength. Hence, fibers and coir pith incorporated into cement matrix is likely to overcome this weakness, producing materials with increased tensile strength, ductility, therefore, improved durability (cracks limitation). Natural coir pith reinforcement has good effects on fracture toughness behavior, durability, environmental-induced damage and aging.

[0026] Mode for invention; the purpose of the present invention is to overcome the defects of the prior art and provide a novel waste grade coir based cement products. The technical scheme of the present invention is, it is composed of the following ingredients according to their proportions (by weight percentage): 10 % -30% of treated waste grade coir, and 90% - 70% ordinary Portland cement and water put it in mold or die to take the desired shape. Other cement base conventional additives can be added according to the end product requirement.

[0027] Example 1 explains the practical procedure to develop a batch of waste grade coir pith based cement paving block / partition block as follows;

[0028] • Coir pith is collected from coir production sites.

[0029] • Coir pith is treated with controlled retting for a duration of one month by immersing it in gently flowing water, with the temperature maintained between 23-35 degrees Celsius. After this period, coir pith completely changes its original structure and surface properties and it feels like a bonding powder. This is totally different than chemical treating surface structure.

[0030] • After that period, the coir pith and Portland cement are measured by their weight percentage.

[0031] • Then cement and waste coir pith mix well by adding water and put it in mold or die to take the desired shape.

[0032] • After adequate time cure and dry it and ready to use. For higher strength can be achieved by applying pressure on the mould

[0033] The present invention is introduced as sand less, coir pith based light weight cement product by solving an environmental burning problem. Percentage of Cement / Percentage of Fiber and any chemical / and the pressure on the mold can be varied according the application of the final product. Main possible applications are paving tiles, cement block, pots and other architectural decorative items and any wood application where load bearing nature of the wood is not significant. For instance, grills, fences, door frames, window frames can be made in this innovative technology. Moreover, with the lightness and water-resistant nature of the product can be used as a roofing solutions such as roofing tiles and roofing sheets. As the coir pith mixed in a powder like structure, same formulae can be used for modern 3D printing technology.

[0034] End property of the products made with this innovative technology can be varied by the production method. If the product is used as the paving block, cement block process can be done with the compression molding method. If the end product is made without a compression molding, it has higher percentage of compressibility as 40%. This kind of products has higher ability to absorb external energy such as shock, compression energy without having complete structural failure. Additionally, this product has high flexure and product is not a brittle.

[0035] With the purpose of investigating the compressive strength test result for novel cement coir pith paving blocks, experimental results on cement: coir pith ratio of 70:30 was obtained after 28 days of manufacturing. Said samples were manufactured in a general mixing and molding method without having compression molding. The density of the sample was average 1373kg / m3. Rumbayan et al. ,2020 summarizes that the cement, coir base paving block density in the range of 1230-1536 kg / m3which fit into the category of lightweight blocks. Present invention well fit with the said density range and it also suitable for light weight category. Similarly, the compressive strength results varied in the range of 16 to 36 MPa which is well above the general concrete / coir mixed concrete paving block which is 6MPa. Samples were tested against the test of "Specification for Concrete Paving Blocks", SLS 1425 - PART 1 : 2011. The best observation during the compression test was the when do the compression test for the general cement block, it blasts once at the breaking point and it is not blast for the present innovative paving block. It changes its shape and structure and reduces thickness after cracking its surface. Average thickness % change varies in the range of 12% to 36%. This observation showed the ability to absorb energy in to the structure without having major failure.

[0036] Example 2; present embodiment is well suitable for wood substitute applications. Wood substitute is presently made with cellulose fibers with the thickness range of 5mm to 40mm. The wood substitute products are manufactured in the modern factories with modern machinery of fiber mixing and cement composite preparation. These Wood substitute composite has main product formulation of 20% treated cellulose fiber and 80% of cement and other additives. Similar formulation and similar machinery can be used for the present coir pith as a replacement material for 20% of chemically treated cellulose fiber with same amount of current treated coir pith. Based on the results, it can therefore be suggested that the development of coir pith-cement blocks is feasible for non-structural, non-load bearing, and lightweight construction material.

[0037] Example 3; the current embodiment finds its purpose in applications involving wall partitioning. Specifically crafted for manual handling, the partition wall panel measures dimensions of 8 feet in length, 1 foot in width, and a thickness of 4 inches, resulting in a weight of 30 kilograms. To strengthen the panel, a galvanized net with a 1-inch by 1-inch mesh is incorporated, enhancing its structural integrity. Additionally, grooves are skillfully integrated along the panel's edges to facilitate a secure interlocking of individual panels. This innovation is exceptionally well-suited for employment within modular housing setups.

[0038] Example 4; the current embodiment offers specific application of the current invention in outdoor water exposing applications. Special additives or admixtures are used to enhance the performance and durability of the coir pith based cement product. These chemicals help improve the resistance of the material to water ingress, corrosion, and deterioration. Cement admixtures, such as water-reducing admixtures, super plasticizers, and permeability-reducing admixtures, is added to the concrete mix to improve water resistance and durability. Additionally, corrosion Inhibitors and hydrophobic agents are added to protect embedded steel reinforcement from corrosion, which can be accelerated in a water environment. They help extend the service life of concrete structures. Moreover, Polymer additives can be used to improve the durability and flexibility of the cement product, making it more resistant to cracking and water ingress. It's important to note that the choice of cement hardening chemicals for a specific water environment will depend on the project's requirements, the type of water exposure (e.g., freshwater, seawater, chemical-laden water), and the desired performance characteristics of the coir pith based cement product.

[0039] Example 5; the present embodiment is tailored to specific applications with the slight modifications of its basic formulation. In coir pith based cementitious products; the choice and combination of additives play a crucial role in tailoring the performance and characteristics of the final composite material. Following additives are used to achieve specific characteristics as follows; Accelerators: These additives speed up the rate of cement hydration, which leads to faster setting and hardening of the mixture. Accelerators are particularly useful in situations where rapid strength development is required. Retarders: Retarders, on the other hand, slow down the setting time of cement, allowing for better workability and extended open time. They are useful when more time is needed for mixing, placing, or finishing. Dispersants: Dispersants are added to improve the workability of the mixture by reducing the tendency of particles to clump together. This can enhance the fluidity of the mixture and facilitate its placement. Extenders: Extenders are materials that are added to the mix to replace a portion of the cement. They can enhance the volume of the mixture while reducing the amount of cement needed. This can lead to cost savings and improved sustainability. Foamers: Foamers are used to introduce air or gas bubbles into the mixture, resulting in a lightweight and porous structure. This can lead to improved insulation properties and reduced overall weight. Fluid Loss Additives: These additives help control the loss of water from the mixture to the surrounding environment. They are particularly important in applications where maintaining proper moisture content is crucial for the material's performance. The ultimate goal of incorporating these additives into coir pith based cementitious products is to create a composite material that exhibits the desired mechanical strength, workability, durability, and other specific properties for the intended application. By carefully selecting and using these additives, manufacturers can tailor the properties of the final product to meet the requirements of different construction and engineering projects.

[0040] Industrial Applicability; The present invention is well suitable for any application of mouldable cement products such as statues, pots, tiles, roofing sheets, fences, door / window frames, grills, partition walls, paving blocks etc. The best applications are light weight applications and it is not recommended to load bearing applications. One of the significant applications of the present invention is in the construction industry. The recent push towards green and efficient buildings and reducing the use of concrete provide a great opportunity for use of coir pith in the building and construction industry. Directly combining the coir pith in sand less cement mixture not only improves mechanical properties but also provides corrosion resistance. Additionally, Ability of coir pith to improve thermal and acoustic insulation improves its applicability in different industries.

[0041] Coir Fiber based cement is an innovation in the Fiber cement industry. There are multiple similar products available in the market that is made of either asbestos or cellulose. Since the discovery of health hazardous nature of asbestos, cellulose is encouraged for the fiber-based cement products. Cellulose is produced out of wood pulp which requires different manufacturing process. Coir fiber-based cement is having all the benefit of cellulose fiber cement plus it is expected to be stronger than cellulose based products. Unlike cellulose which requires manufacturing process coir fiber extraction is very simple and cheap comparatively. With all this qualities, present innovation is market applicable composite.

[0042] Present invention of coir pith in cementitious composites is an alternative in nonstructural construction materials that can reduce the price, energy cost, and environmental impact. When the composite use as a wood substitute products, present composite is applicable in floor decorations, wall decorations, ceiling, eaves decorations and other multipurpose decorations (Figure 2). If it is applied on a load bearing capacities, it is recommended to use bottom reinforcement such as concrete flooring for novel wood substitute attachment.

[0043] Present cementitious composite is well suits in the cement based pavement block or partition block applications. The incorporation of such coir pith as cement based materials offers significant potential for the development of low-cost and local construction materials for affordable housing, utilization of coir pith into cementitious matrices is very suitable application for earthquake resistant construction materials. Generally, fiber reinforced cementitious composites are fascinating for Indonesia, which located in an area with risk of intense earthquakes where present invention is well suitable for that specific application. Besides, Making cementitious composites reinforced with coir pith represent one way of recycling waste that is of economic interest for developing countries. The cementitious composite is a material with exciting potential. The price of the material could be 30% cheaper than standard construction materials, and the mechanical properties of cementitious reinforced composites can equal conventional building materials.

[0044] In the field of construction materials, the industry can take part in creating and manufacturing environmentally in a friendly cementitious materials made from local environmental waste and natural raw materials. Present inventive material can lead to useful material for developing countries. Therefore, to build with cement materials reinforced with coir pith is one way to achieve sustainable development. Hence, the current inventive material is sustainable, energy efficient construction material, on alternative materials that can reduce the cost and environmental impact of building processes. Some of the examples are a wood applications, decorative applications, nonstructural applications like Grills, Fences, Door frames, Window Frames, etc., Roofing Sheets / Tiles where with the lightness and water-resistant nature of the product can be used as a roofing solution.

[0045] Additionally, Coir pith is renewable and sustainable resources. It can found in a large amount worldwide including in Sri Lanka. In addition to Sri Lanka, About 87% of coconuts lands located in the countries member of the Asian and Pacific Coconut Community (APCC). Overview of the state of the art in natural fiber cement-based composites research highlights the need to develop alternative and sustainable new materials, using local, energy-efficient, low-cost materials with low environmental impact. Hence, present invention is locally optimized material which has good end qualities.

Claims

Claims1. A method for preparation coir pith based cement composite comprising steps of:Coir pith undergoes controlled retting for a duration of one month by immersing it in gently flowing water, with the temperature maintained between 23-35 degrees Celsius; mixing 10-30% treated coir-pith with 90-70% ordinary Portland cement by weight; adding additives if require; adding adequate water; moulding of the mixture with or without applying pressure on the mould and allowing to solidification of cement coir pith mix-based structures.

2. The method for preparation coir pith based cement composite in claim 1:Wherein solidified objects are coir pith mix-based structures of paving blocks, wood substitute products, bricks, partition blocks and similar load-non bearing structures.

3. A formulation of coir pith based cement composite comprising: at least 10 % -30% of treated coir pith, 90% - 70% ordinary Portland cement by weight and suitable additives and adequate water, wherein said Coir pith undergoes controlled retting for a duration of one month by immersing it in gently flowing water, with the temperature maintained between 23-35 degrees Celsius.

4. The formulation of coir pith based cement composite of claim 1: wherein the formulation comprising 20% of treated coir pith, 80% ordinary Portland cement, conventional additives by weight and adequate water.

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