WO2009007994A2

WO2009007994A2 - Composition of materials for production of fly ash, pre polymerized resin composite

Info

Publication number: WO2009007994A2
Application number: PCT/IN2008/000264
Authority: WO
Inventors: Shilpa Pradeep Joshi; Pradeep Vasant Joshi
Original assignee: Shilpa Pradeep Joshi; Pradeep Vasant Joshi
Priority date: 2007-04-27
Filing date: 2008-04-25
Publication date: 2009-01-15
Also published as: WO2009007994A3

Abstract

The present invention relates to a composition of the material for the production of fly ash pre polymerised resin composites. More particularly the invention relates to polymeric binding compositions and particularly to coating compositions useful as an adhesive for clay bricks, Fly ash bricks, aerated concrete blocks, cement blocks etc., used as building blocks for civil construction activities, as plaster /render for building surfaces, as a crack filler, as a repair plaster, as a fire and heat resistant plaster/ mastic etc. The product is designed to be used in building / construction industry as a self-curing, crack resistant, eco friendly, ready to use composite useful as a brick / block laying adhesive, render/plaster, crack filler, repair plaster, etc. The composition composed of ultra fine pulverized fly ash, a low viscosity Poly vinyl acetate (VAM), styrene acrylic, pure acrylic, CNSL (cashew nut shell liquid), Silicon, Shellac type emulsion polymer as a binder and water. The composition also preferably contains one or more of a dispersant, a de foamer, a plasticizer, a thickener, a drying agent, preservative, a fungicide, silica or quartz fillers of different mesh and an ingredient to control the pH of the composition.

Description

"COMPOSITION OF MATERIALS FOR PRODUCTION OF FLY ASH, PRE POLYMERIZED RESIN COMPOSITE"

FIELD OF THE INVENTION The present invention relates to a composition of the material for the production of fly ash pre polymerised resin composites more particularly the invention relates to polymeric binding compositions useful in civil engineering.

BACKGROUND OF THE INVENTION The bonding mortar typically contains Portland cement, sand /silica and water as main ingredients, where Portland cement and silica of specific grade are mixed in a ratio of 1 :4 or 1: 5 and sufficient quantity of water is added for workability. Often additives such as fibres, re-dispersible polymers and waterproofing compounds etc., are added to enhance the resistance to water, and resistance to cracking etc. The purpose of the mortar made thereof is to hold the bricks/ blocks together and to bind them to each other, and the strength of the bond is supposed to be more than the strength of the brick / block. Curing with potable water for 7 days minimum is essential to complete the hydration process within the mortar and attain the optimum strength of the mortar bond.

Inadequate curing adversely affects the hydration process and the strength gaining of cement in the composite. Upon drying there is shrinkage in the bonding material, leading to minute gaps, loosening out and de-bonding the substrates held together, The material also gets brittle upon hard drying. Curing in hard water also affects the properties due to presence of contaminations. The most common present practice of mortaring in masonry work is 'on site mixing' of cement, sand and water in the defined ratio. The applicator mixes the raw materials with the water available on site. Other commonly used mortar has been Portland cements plus lime but outdated technology. Both these materials are applied with trowels (naila) between the brick surfaces, to bind .All the mortaring materials are Portland cement based, with additives of varied nature to improvise different properties such as crack reduction, strength, ease in application, weathering etc. The Portland cement-based mortar needs post watering for curing. Post curing of mortar is affected by sprinkling of water thereby causing expansion of cement particles (hydration) thus forming a compact structure. Curing of cement has to be a normal ambient 20-30 C in humid atmosphere. At low temperature the rate of curing is affected negatively. Cement based products are pre-designed for short pot life and difficult for handling. In case of slow working the cement -sand mixture gets hydrolysed and get thicker thus affecting adhesion and curing rate. During application the mason has to apply the cement based mortar with effort (a fatigue creating job). During application half of cement based products fall on the ground and reused in fresh mixture thus affecting the quality of plastering. In general, application the rate of wastage may run to 10-15 % mass basis. Similar method is used for rendering the surfaces constructed with bricks/ blocks etc. The proportion of cement: sand is standardised as 1 : 4 to 1 :6 with water suitably mixed. The quality and gradation of particles of the silica used play a crucial role in the final properties and performance of the plastered surfaces. The plasters are made on site as per specified proportions and used immediately due to pot life limitations. The application needs post water curing to avoid cracking on surfaces. The water used for mixing the Portland cement and sand is used for formation of CSH by combination of water and CaO and sulphates present in the Portland cement, which attains its 60% of total strength in 28 days. Loss of water from the product during this time, leads to inadequate strength to the plaster. The heat of hydration produced during this process is high. Inadequate curing thereby leads to cracking on surfaces. There is no readily available material for repairing the damaged surfaces of plaster specially found in old constructions. The regular Portland cement plaster is prepared and additives such as plasticizers and water proofing chemicals are added to the product. However the materials are basically in dry powder form and mixed with water on site. The bonding between the existing surfaces and the old surfaces is not always good and the patches seem to appear after the repair work. Some times de- bonding is also observed. The repairs as such tend to show patch works and not a homogenous surface. The pot life of the repair mix is also limited.

The cracks seen on wall facades, external or internal are a big issue in the construction industry. These cracks arise due to several reasons some of which are uncontrolled such as uneven settlement of masses, while few others arise out of common construction practises, such as inadequate curing, the quality of raw materials in composite mix, application process, time gap between construction of the two surfaces, and so on. These cracks need to be filled with suitable material, which binds the two edges of the crack, and prevent the ingress of water, which ultimately leads moisture in wall, fungal development and damage to the structure therein. The most common practice of filing these cracks is by mixing Portland cement, with fine graded silica, plasticizers, waterproofing chemicals/construction chemicals and water. These ingredients are suitably mixed on site, before application and used immediately due to short pot life. Curing of surface after application is essential to ensure bonding. There is often a tendency of shrinkage, which loosens out the material, leading 80 to expansion of cracks.

The new invented product is designed to overcome all these issues caused due to presence of Portland cement, by suitably varying the various ingredients, and/ or their proportions in the composite.

85 PRIOR ARTS

The use of Fly ash and polymer emulsion is quite old. There are references made to such combinations. The invention of Cold waterless setting mortar relates to the use of fly ash, containing controlled amounts of fly ash along with few other types of filler natural or to provide requited formulations.

90 Micheal L Yap in American Patent has suggested fly ash, which is to be. mixed with coal tar emulsion for sealing driveways. US Patent 4229329 records the use of fly ash along with other inorganic fillers and glass powder in emulsions for application as Fire retardant coatings and use has been suggested in high- rise buildings. As per this patent the fire retardant coating composition useful as

95 paint or as mastic is composed of ultra fine pulverised fly ash, a low viscosity Vinyl acrylic type emulsion polymer as binder in water. The composition suggests use of 24 % Fly ash and 24-50 % Emulsion as paint coating having good flexibility. .

Manjit Singh and Mridul Garg have studied Flyash as reactive pozzolonic 100 materials. The name pozzlana is derived from Latin pulvis puteolanus and refers to pyroclastic deposits erupted by Campi Flegrei volcanic field. Long back in ancient time it was discovered that these pozzolonic deposits with lime produced exceptional cement. Pozzolonic materials by themselves are not cement, but contain reactive silica, 105 which reacts with lime to setting hard cement in time. Artificial pozzlana are made from fly ash produced by coal burning power plants all over the world. They have suggested use of such materials for sandwich composite designs combining high tensile strength skins with lightweight, rigid core. US Patent 7255738 B2 suggests use of lightweight cementitiuous materials for 110 composite boards and partitions such as insulating panels.

Mason bond based on use of Polyurethane has also been claimed on similar basis for use as adhesive for building blocks in US of America. However the use of fly ash is not indicated in the data available about the product.

115 OBJECT OF THE INVENTION

The newly invented Eco Friendly Composition of fly ash, pre polymerized resin composite without Portland cement offers solution on various problems arising during and after mortaring and plastering of the walls. The product is designed to offer total replacement to conventional Portland cement based mortars and

120 plasters, and is useful for crack filling as well as repairing damaged plastered surfaces.

It is applicable directly on conventional brick walls, concrete blocks, Flyash bricks, concrete materials, stone, Ply boards, Asbestos cement sheets etc. The product is completely Portland cement free and designed as based on

125 waste recycled products such as Flyash, polymer binder of the type - Pure Acrylic, Styrene Acrylic, Poly Vinyl Acetate, or Chloride, Poly urethane, CNSL, Shellac, Silicon emulsion, Tar etc and other fillers such as stone/silica fillers, bio products like fibres. On application it needs NO POST CURING with precious water. It is designed

130 to save time in application and post treatment, as well as saves manual labour.

It is a ready to use material and the quality is controlled at manufacturing factory end. It is an eco-, user- and bio- friendly material. The product is easy to apply with the help of a metallic or plastic trowel and does not require any muscle power to throw the material on wall bricks and generating any wastage.

135 The flow of the product can be adjusted to make it suitable for pumping, squeezing etc

SUMMARY OF THE INVENTION

140 The present invention relates to a composition of the material for the production . of fly ash pre polymerised resin composites more particularly the invention relates to polymeric binding compositions and particularly to coating compositions useful as an adhesive for clay bricks, Fly ash bricks, aerated concrete blocks, cement blocks etc., used as building blocks for civil

145 construction activities, as plaster /render for building surfaces, as a crack filler, as a repair plaster, as a fire and heat resistant plaster/ mastic etc. The product is designed to be used in building / construction industry as a self-curing, crack resistant, eco friendly, ready to use composite useful as a brick / block laying adhesive, render/plaster, crack filler, repair plaster, etc.

150 The present invention contributes materially to the solution of both of the foregoing problems. In accordance with the invention an effective binding cement composition is composed basically of fly ash, a vinyl, styrene, acrylic CNSL, Shellac type polymer emulsion binder and water. The Binding composition in accordance with the invention is useful as a mortar which can be 155 applied to bricks, fly ash building/ blocks to provide a adhesive building mortar layer, as a plaster/render, crack filler and repair mortar/plaster etc. The invention thus contributes to Building industry and also contributes to improvement of the ecology by providing a valuable outlet and use for waste fly ash, as well as by saving the water requirement. This relieves the problem of

160 disposing the fly ash as a waste material.

The adhesive binding mortar composition in accordance with the present invention consists basically of ultra fine pulverized fly ash, a heat resistant synthetic latex binder and sufficient water for rendering the composition sufficiently thick for application to a brick's surface as a thick mortar layer or

165 coating, for example by trowelling. The composition can also be mixed with fibrous or other filler for enhancing properties such as crackles ness, strength, water resistance, heat and fire resistance etc.

The fly ash is of the kind recovered from flue gases in the combustion of coal and is preferably of a fineness to pass through a 180-mesh screen. If the fly

170 ash as recovered from the flue gas contains larger particles, these are screened out or the fly ash is pulverized, for example in a ball mill, to reduce the particle size. If the fly ash recovered from the flue gas contains combustible particles, for example unburned carbon, they are burned out or otherwise removed. The ultra fine fly ash is the basic component of the composition and

175 preferably comprises 7% - 80 % of the composition by weight. In some cases it has been found desirable to include in addition to the fly ash lightweight inert inorganic material such as calcite, marble, calcium carbonate, silica, china clay in the form of fine powder. Mixing fly ash of various grades in terms of its particle sizes is beneficial as it supports the faster drying, increases water

180 resistance due to close packing of particles, increases the mechanical strength, shear strength, etc. Bottom ash, fumed silica, rice husk etc can optionally be good replacements partially or fully or in combination.

The C type Fly Ash consists of higher percentage of CaO when compared to the F type of Fly Ash, which gives better pozzolonic properties to the C type;

185 when compared to the F type. However the CaO present in the F type Flyash, in the presence of moisture hydrates to form CSH, which adds to the strength of the composite. The combination of Fly ash and water does not posses enough strength on its own to fulfil the expectations of the mortar. However, the hydration of fly ash and the reactive silica present adds to the strength together

190 with the binder used.

BREIF DESCRIPTION OF THE INVENTION

The present invention relates to a composition of the material for the production of fly ash pre polymerised resin composites more particularly the invention

195 relates to polymeric binding compositions and particularly to coating compositions useful as an adhesive for clay bricks, Fly ash bricks, aerated concrete blocks, cement blocks etc., used as building blocks for civil construction activities, as plaster /render for building surfaces, as a crack filler, as a repair plaster, as a fire and heat resistant plaster/ mastic etc. The product

200 is designed to be used in building / construction industry as a self-curing, crack resistant, eco friendly, ready to use composite useful as a brick / block laying adhesive, render/plaster, crack filler, repair plaster, etc. The term Polymer emulsion defines trade available water based colloidal dispersions manufactured by polymerisation process of either acrylic or

205 polystyrene polymers. Polymer emulsions can enhance the applicability and flow properties and strength of such products. The binder used is a low viscosity vinyl acrylic type emulsion polymer having the properties of being stable and compatible with other components and of forming a film which is tough and flexible and resistant to cracking and which

210 has outstanding permanence, durability, adhesion and binding capacity. The binder is totally water thin able and stable at all normal conditions of storage and usage. The amount of binder used is 1 - 40% (solid content)of the composition by weight. Proportions have varied as per the purpose of the product and its desired properties ad performance. A binder that has been

215 found satisfactory is 261 , 500, 2438, which are 100% acrylic emulsion polymer produced by Rohm & Haas Co. It is designed to give excellent outdoor durability and excellent adhesion under damp or dry conditions. Moreover, mortar compositions made with these polymer emulsions are easily applied and dry rapidly to produce films with extended flexibility and excellent resistance to

220 blistering, grain cracking and flaking. Use of 398 which is a styrene Acrylic emulsion also gives satisfactory results as the mortar is not subjected to out door weathering, It gives satisfactory strength and other properties.

For the composite usable as Plaster, it is advisable to use Pure Acrylic resin 225 Emulsion as binder to enhance the sustaining to weathering.

The fly ash is of the kind recovered from flue gases in the combustion of coal and is preferably of a fineness to pass through a 180-mesh screen. If the fly ash as recovered from the flue gas contains larger particles, these are screened out or the fly ash is pulverized, for example in a ball mill, to reduce 230 the particle size. If the fly ash recovered from the flue gas contains combustible particles, for example unburned carbon, they are burned out or otherwise removed. The ultra fine fly ash is the basic component of the composition and preferably comprises 7- 80 % of the composition by weight. In some cases it has been found desirable to include in addition to the fly ash lightweight inert

235 inorganic material such as calcite, marble, calcium carbonate, silica, china clay in the form of fine powder. Mixing fly ash of various grades in terms of its particle sizes is beneficial as it supports the faster drying, increases water resistance due to close packing of particles, increases the mechanical strength, shear strength, etc.

240 The C type Fly Ash consists of higher percentage of CaO when compared to the F type of Fly Ash, which gives better pozzolonic properties to the C type, when compared to the F type. However the CaO present in the F type Flyash, . in the presence of moisture hydrates to form CSH, which adds to the strength .-. of the composite. The combination of Fly ash and water does not posses -

245 enough strength on its own to fulfil the expectations of the mortar. However, the , hydration of fly ash and the reactive silica present adds to the strength together with the binder used.

The thinner used in the composition is water, which may constitute from (8- 55%) by weight of the composition depending on the use to which the

250 composition is to be put like burnt clay bricks of fly ash blocks and their porosity. Building blocks need more water for absorption. In addition to the basic ingredients described above, the composition preferably contains one or more of the following additives, namely inorganic pigment, a dispersant, a de foamer, a plasticizer, a thickener, a drying agent, a

255 preservative, a fungicide and an agent for controlling the pH of the composition so as to inhibit corrosion when the composition is applied to a metal surface. As the fly ash is light grey in colour, an inorganic pigment can be added when other colours are desired. A suitable pigment is titanium dioxide (TiO₂ - R900), which is a conventional white pigment and hence lightens the colour of the

260 composition. For example, the Tiθ₂ can be used in an amount of for example 1- 10% by weight of the composition. Additional or other pigments can be used when other colours are desired.

To assist in dispersing the fly ash and any pigment in the binder and the water, it is desirable to use a water-compatible dispersant such for example as

265 Sodium hexa meta Phosphate, The amount of dispersant used is preferably in the range of 0.1% to 0. 5% by weight.

In order to prevent foaming of the composition when it is being mixed, it is desirable to use a water-compatible de foamer. The amount of de foamer used may vary from 0.3 -1.5% by weight.

270 In order to increase the plasticity and flexibility of the composition, it is desirable to use a plasticizer such as Texanol produced by Eastman Chemical Products Inc. The composition of Texanol is 2,2,4-trimethyl-1 , 3 - pentanediol mono-iso- butyrate. Another suitable plasticizer is tricresyl phosphate. Depending on the application for which the composition is to be used, the amount of plasticizer

275 may vary from 0.2 - 2% by weight.

For easy application in thick film desired, a thickener such as Cello size QP15000 produced by Union Carbide Corporation can be used. Cello size is hydroxyethyl cellulose produced by reacting alkali treated cellulose with ethylene oxide under carefully controlled conditions. The amount of thickener

280 used may vary from 0.1-1.0% by weight.

It is also desirable to use a drying agent to expedite the drying of the composition. Suitable drying agents are Nalcoag 1034-A and Nalcoag 1050 both produced by Nalco Chemical Company. Nalcoag 1034-A is acidic pH aqueous colloidal silica dispersion, which is relatively non-toxic. Nalcoag 1050 285 is a colloidal dispersion of submicron size silica particles in the form of tiny spheres. Sodium silicate can also be used as a drying agent. The amount of drying agent used may vary from 0.1- 6% by weight. Drying of the mortar can also be affected by variety of range of particle size of Fly Ash. Higher range particle size reduces drying time.

290 In order to increase the shelf life of the composition it is desirable to include a preservative such as Dowicil 75 produced by the Dow Chemical Company. Dowicil 75 is 1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride to which a stabilizer (sodium bicarbonate) has been added. The amount of preservative used may vary from 0.1-1.0%.

295 In as much as the composition is water base, it is desirable to include a fungicide to inhibit the growth of any fungi in the composition. A suitable fungicide is Nopcocide N-96 produced by Diamond Shamrock Corporation. The chemical composition of Nopcocide N-96 is 2,4,5,6-tetrachloro-isophthalonitrile. The amount of fungicide used may vary from 0.1 -1.0%.

300 It has also been found desirable to include in the composition about 20-30% by weight of silica / china clay / Calcium carbonate / stone chips which act as inorganic fillers. Other fillers like coconut shell chips / crushing of various sizes further augmented this. Optionally, fillers of different mesh of sources such as silicates, quartz, stone crushing, coconut shell crushing, Polystyrene balls/

305 shavings, vermiculite / perlite, fibres etc. are useful in adding to the bulk, and increasing the workability as well as to adjust drying time. Using additives such as Wax Emulsion with silicon reinforcement supports the water resistance of the product. It has also been found desirable to include in the composition a non-ionic

310 surfactant such as lgepal CO-630 produced by GAF Corporation. The chemical composition of lgepal CO-630 is nonylphenoxypoly-(ethyleneoxy) ethanol. The amount of surfactant included in the composition may vary from about 0.2-1%. Optionally it is possible to achieve similar results by replacing water based resin system dissolved in suitable solvent such as MTO / xylene. However it

315 affects the cost of the materials. Examples include alkyd, CNSL, Coal tar etc. It is a ready- to- use material and needs no mixing on site. It is available in easy handling packing as per demand. This enables control both on quality and quantity. There is no need of water, which not only saves it but also prevents on site contamination.

320 It is completely free from conventional Portland cement and needs no curing under water or stopping the water evaporation. This saves water as well as time in construction. It is most suitable replacement to conventional mortar and plaster in today's world, which is facing cement and water shortage. The composite has excellent resistance to cracks, which arise in all mortars

325 and plasters over a period of time due to various reasons.

The product has excellent adhesion to the substrate. The product is hence lifelong use.

It is very easy to apply. It needs very less time and effort compared to conventional mortars, and plasters and similar applications as mentioned

330 above.

It is an eco-friendly product, which contains ingredients such as Fly ash, which improves the ecology.

On demolition it can be simply used for land filling and is absolutely harmless. It is possible to apply any paint / texture / coating on the mortars.

335 It has excellent resistance to water and does not permit growth any fungus or mildew growth. The application on brick lying can be mechanised by airless supply nozzle, or simply applied by squeeze mechanism. EXAMPLES

340 The following non-limiting examples are illustrative of adhesive binding mortar compositions in accordance with the invention:

EXAMPLE 1

345

EXAMPLE 2

EXAMPLE 3

350 The composite of the said invention has been tested /evaluated as following manner

EVALUATION OF COMPOSITE Evaluating Tensile bonding strength

355 Apply mortar to burnt clay bricks and attach another clay brick to the other end, Let the joint dry for 48hr. do not disturb the mortar layer, after drying duration of 48 hr; the bond can be tried for breaking by handing weight to the brick end while on while on of the two was held on the table thus forming a cantilever. Weight was hanged from the brick end in an increasing way till the joint give 360 away. It was observed that the joint survived the strength test while clay brick broke thus giving way to the joint strength.

365

Bricks / blocks

weight hung

the bottom f

380

Shear Bonding

385

In a test mastic made material was applied in4mm thick to one side of a wooden ply plate approximately 25mm wide and 75 mm long. This is covered by another ply piece of similar specification only covering the mastic portion 25 x 25 mm after the mastic had been allowed to cure for two days, the block was 390 suspended in a vertical position from a rack on a spring balance with a hook attached to the other ply piece. Continuously increasing weight is added to the hook at lower end thus making the joint break. 395

Holding Weight test -

In a test, mastic was made in a block admeasuring @5cm. X 5cm. X 6mm. and

425 allowed to cure completely. Weights of various measures were then dropped upon the hard dry cuboids, from a distance of 1 metre to see the depression made on the cube. Similar tests were conducted on the cubes of conventional mortar. Various depressions were noted as made with different weights till the cube broke.

430 435 Weight dropped from 1 m height

440

Cuboid of the material

445

Strength test -

To check the strength of the bonds in comparison with the walls built in conventional mortar the product was given to several masons, engineers, and architects and building contractors. Walls of clay bricks, concrete blocks, fly ash

450 bricks etc were built using the said adhesive material.

Upon hard drying, the walls were hammered for demolition. After long efforts walls broke with the breakage of blocks/ bricks while the bond remain intact.

Water absorption test-

455

The water test has been tested under two sets of conditions

1 - In a test, mastic was made in a block admeasuring 5cm. X 5cm. X 6 mm. and allowed to cure completely. It was then immersed in water for 2 hrs and 460 then allowed to dry naturally for 2 hrs. This was repeated in cyclic pattern. Weights of the cubes before and after immersing were noted. Also the physical conditions were observed. The difference in weights indicated the absorption and loss of water. The condition of the material indicated the effects of the process in cyclic pattern.

465 2 - In a test, mastic was applied in uniform thickness of 6 mm on a glass tile. Upon hard drying the mastic was dipped in water for 24 hr. and change in weight was noted to indicate water absorbed by the mastic. Temperature cycle test- In a test, mastic was made in a block admeasuring @5cm. X 5cm. X 6mm. and

470 allowed to cure completely. The cubes were then subjected to temperatures up to 60 ° C in a lab oven and then to temperatures as low as - 6° C Cyclic pattern was maintained to check the impact of temperature difference. Shrinkage test- In a test, mastic was applied in uniform thickness of 6 mm on a glass tile. The

475 thickness of mastic along with glass thickness was noted. The same was measured upon hard drying to check the difference in the film thickness.

Adhesion test- In a test, mastic was applied in uniform thickness of 6 mm on a glass tile. Upon

480 hard drying the mastic was checked with tape test to check its bonding to the substrate. Similar tests were conducted on various substrates. Material stability test :

The composite was kept in a open pot , and subjected to varying grades of temperature between '- 6o' to ' 60o' C ,in a cyclic pattern .In 10 cycles no

485 change was found in the condition of the composite , in terms of its properties . However the pot life varies slightly in higher temperatures above 5Oo C and the material tends to dry faster. Some of the results obtained from the tests with various combinations of the ingredients and their proportions are averaged and a range of obtained results 490 is tabulated as follows:

Effect of composition on specific properties :

1. Bond strength increases with aging .

2. Bond strength increases on increasing the binder in mortar

495 3. Bond strength increase with the thickness applied .

4. Bond strength decreases as per reduced quantity of fly ash.

5. Bond strength is free of fillers added,

6. Effect of change of type of binder - Pure acrylic resin emulsion and styrene offers best bonding properties. Other binder resins studied also

500 offer optimum range of strength. 7. Effect of type of fly ash 'F' and 'C (F contains CaO to the extent of 1- 12% while C contains CaO to the extent of above 12 %). Another grade of 'F' containing lower %age of CaO has also been tried and found to offer lower strength but still better than that of bricks or Portland cement

505 mortars.

8. Particle size range of fly ash used also affects the water content in the mortar and hence the coverage. Water evaporates on drying (not curing) but due to compact nature of fly ash produce minimum seepage in the mortar layer.

510

PREPARATION

In the foregoing examples all of the percentages are by weight. • The mortar composition in accordance with the present invention can be conveniently produced in a rotary mixer (pug mill)

515 The water, dispersing agent, antifoaming agent and preservative are introduced in the mixer and mixed for about five minutes at a speed of for example 200 RPM. Pigments, pulverized fly ash and other solids are introduced and mixed for about twenty minutes. This is followed by the binder and plasticizer mixed for about five minutes. Remaining constituents such as sodium silicate, colloidal

520 silica and Dowicil 75 are added while continuing the mixing for another ten minutes. The speed of the mixer is appropriately reduced according to the thickness and viscosity of the composition.

525

Claims

WE CLAIM

1. A composition of materials for production of fly ash pre polymerized resin 530 composites consisting essentially of

(a) Finely divided fly ash/bottom ash of different mesh size 7% - 80%;

(b) A binder (with dry solid) 1 % - 40%;

(c) Water 10% - 25%; 535 (d) Additives such as dispersants < 1 %

Preservatives, antifoams

Dispersant, Preservative, Antifoam

(e) Fillers -10 to 22%

540 2. A composition of materials for production of fly ash pre polymerized resin composites as claimed in claim 1 wherein the binders are low viscosity vinyl acrylic emulsion polymer

4. A composition of materials for production of fly ash pre polymerized resin 545 composites as claimed in claim 1 wherein a fly ash is mixed with polymeric emulsion in order to achieve around 25 mm thickness;

5. A composition of materials for production of fly ash pre polymerized resin composites as claimed in claim 1 wherein fly ash is mixed with the proportion of

550 Emulsion is 1 - 40 % on dry solid basis.

6. A composition of materials for production of fly ash pre polymerized resin composites as claimed in claim 1 wherein the fillers are silicates, quartz, CaCO_3, talc, chalk and like;

555

7. A composition of materials for production of fly ash pre polymerized resin composites as claimed in claim 1 consisting optionally: a) Cellulose fibres, b) Thickeners, 560 c) Ceno spheres, d) Vermiculite, e) Surfactant, f) Silica, g) Crushed stone fillers,

565 h) Expanded polystyrene balls / filings, i) Marble powder, j) Coconut shingles, k) Inorganic pigment,

I) Wax emulsion;

570 m) Bottom ash n) Fumed silica

8. A composition of materials for production of fly ash pre polymerized resin composites as claimed in claim 1 to 7 is applicable on clay bricks, fly ash

575 bricks, aerated concrete blocks, cement blocks and can be applied on wet fresh conventional Portland cement layer and shows excellent bonding;

9. A composition of materials for production of fly ash pre polymerized resin composites as claimed in claim 1 to 8 is used as a mortar, plaster, and crack 580 filler and repair mortar.

585

590

595

600