US1636367A - Process of coating concrete pipes and hollow bodies with bituminous compositions - Google Patents

Description

July 19, 1927. 3

R. ILLEMANN PROCESS OF COATING CONCRETE PIPES AND HOLLOW BODIES WITH BITUMINOUS COMPOSITIONS Filed Jan. 15, 1926 Invent or. Rillcrn unnb q a Patented July 19, 1927.

UNITED. STATES PATENT OFFICE.

ROBERT ELEMANN, OF GLASGOW, SCOTLAND. I

PROCESS OF COATING CONCRETE PIPES AND HOLLOW BODIE$ WITH BITUMINOUS COMPOSITIONS.

Application flledlanuary 15, 1926.

It is known to manufacture concrete pipes and other hollow bodies from a composition of cement and sand, or any other suitable aggregate, by centrifugal action, i. e.-by a spin- 5 ning process, also to hand mould or cast such pipes or bodies when the concrete is in a liquid or semi-liquid condition.

My invention relates to a process and also to a composition of matter, forfuse in the rocess, whereby pipes or other hollow odies made of concrete'can be'efi'ectively coated or lined on the inner surface and also, if required, on the outer surface with a bituminous-stone flour coating.

The ractice usually adopted, up till now, for ma ing'concrete pipes and 'linin them with a hot bituminous material is, rst, to spin the pipes from cement and any suita le aggregate and stack them away for set- 0 tin and hardening, which takes several wee s, perhaps months, before the necessary hardness is attained for the various water pressures which the pipes are required to resist when the ipes are in use.

l The main di culty and drawback up till now is that such "concrete ipes, even if they are hard and it is intende to line them with an inner coating of a hot bituminous material, require a specially prepared inner surface characterized by keys and rooves made when the concrete is soft; or, 0t erwise, stone chips thrown in and partly embedded in the concrete so as to provide a rough inner surface on the pipe these chips serving, when i the concrete is set, as keys to give a gri or hold, to a certaln extent, for the hot b1- -tuminous substance.

I have found theforegoing practice is not only expensive but it is most unreliable for l the reason that the dampness or moisture which is still present in the hard concrete renders it impossible for the hot bituminous substance to adhere closely anduniformly on the inner surfaceof the concrete pipe.

i If it is sought to drive of the moisture from. the concrete pipe by heat and at the same time allow the inserted hot bituminous mass to run freely in the pipe, then I find a fine dusty film is formed due to the cement being overheated or killed and this film of fine dust on the inner surface of the concrete pipe prevents the hot bituminous substance adhering and uniformly uniting to Serial No. 81,473.

the concrete so that there is not an effective combination of the concrete and the bituminous substance.

The object of my invention is to overcome these difliculties.

According to my invention I manufacture bituminously lined pipes or other hollow bodies of concrete by spinning a mass of concrete to form the body, introducing a quantity of cold, aqueous, liquid bituminous composition into the body while the latteris still wet, continuing the spinning of the body to distribute the composition over the interior surface of the body and thereafter allowing or causing the concrete and the bituminous composition to set simultaneously.

As a liquid bituminous composition I prefcrto use one whose preparation is hereinafter fully described.

In carrying out the invention I proceedas follows I prepare a cold, aqueous bituminous waterproofing composition, before the concrete pipe is made, by first making a creamy mixture of stone, reduced by grindin crushing, or otherwise, to a condition suc as flour, powder or dust, (hereinafter referred to as stone-flour) and water, and heating the same to boilin' point and agitating it, and then adding bitumen in a liquid condition by pouring same into the aforesaid boiling mixture the boiling being kept up and the mixture kept in a state of constant agitation until the mass is brought to the consistency 'of a stiff paste. I then put the same amount of water into the mixture as has been evaporated by the boiling, thinning it down further with water, according to requirements, and I continually stir and agitate the whole mass till it is cool. In making the com osition I may use the stone-flour and the bitumen in the pro ortion of about, for example, 48 lbs. by weight of the stone-flour fluid to 18 lbs. by weight of bitumen and this proportion I ma vary according to the specific gravity of t e materials and the bitumen used..

I wish it to be understood that when I use the.expression stone-flour in the speciification and the claims appended I wish the same to cover and include stone reduced to a floury state; stony matter such as slate,

or sand, in a similar state (the sand being reduced to a state finer than its natural state); and plumbago on graphite. \Vith these substances no contraction of the composition occurs on drying, which is an important consideration.

I then proceed to spin the concrete pipe and as soon as the pipe is spun and made and while still wet and moist I immediately pour several gallons of the cold, aqueous bituminous composition inside the concrete pipe and continue the spinning thereby distributing the composition, specially prepared for the purpose, all over the inner surface of the concrete pipe by centrifugal action and the composition will adhere and unite firmly with the wet concrete forming an even layer of bituminous composition on the inside thereof and rendering the pipe nonporous, waterproof and acid resisting and ready for use when dry.

After the spinning and lining of the con-- crete pipes with the said bituminous composition is com leted they are stacked away to dry and bar en, the bituminous composition and concrete bindin together and setting and hardening simul taneously.

For lining such pipes if required with a hot bituminous mixture containing no water, I proceed as follows ,I take one or more concrete pipes previously treated as aforesaid with a coating of the before described mixture, when they are hard and dry, and place them back on the spinning machine, or any other suitable revolving device, and I close up each end of the concrete pipes temporarily in such a manner as to prevent the hot bituminous composition from running out when poured into the concrete pipes.

It is advisable before the hot bituminous composition is poured in, to warm the interior of the pipe with hot air or similar means, in order to allow the hot bituminous composition to run freely and evenly and prevent the sudden chilling of the same.

After the required quantity of the hot bituminous composition has been s un and distributed evenly in each pi e, t e pipes can be quicklv cooled down, rom the outside, with cold water applied by a water hose, or any other suitab e means, the pi es being revolved all the time until the 0t bituminous composition inside the pipes is cold and hard and has firmly adhered to the first applied bituminous composition so as.to form on the inside a hard black and glossy lining after-which the pipes are ready for use.

The quantity and thickness of the hot bituminous coating is made according to requirements and to the diameter of and the water pressure to be resisted by the concrete pipes.

Instead of natural bitumen in either of the bituminous compositions mentioned, I

ma use pitch, tar, or similar bituminous an resinous matters or waxes. and which 1' wish to be covered by and included in the term bituminous composition.

To increase the internal strength of the whole concrete pipe I choose a bitumen of most tenacious consistency and increase the melting point of the bitumen by adding thereto small quantities of sulphur flour, or, instead of sulphur, 1 may use stone-flour, and then add so much sand or crushed stone, or any suitable aggregate, to the mixture, till it is of a thick liquid consistency when hot. I may also increase the strength and tenacity of the bitumen by placing a circular reinforcement or an other suitable metallic reinforcement att to inner surface of the finished concrete pipe and pour and spin the hot liquid bituminous composition on top of same combining and surrounding such reinforcement with the bituminous composition and the concrete, thereby considerably increasing the strength of' the whole concrete pipe. The layer of the bituminous composition may be of the same thickness as or more than the thickness of the concrete.

The drawings annexed hereto show such a reinforced concrete pipe, Fig. 1 being a longitudinal section partly broken away and Fig. 2 a cross section, while Fig. 3 shows a piece of reinforcement. Fig. 4 is a perspective view of the pipe. In the drawings a is the concrete, 1) the bituminous-stone lining and c the reinforcement. This reinforcement preferably consists of longitudinal members d consisting of flat metal, such as shown at c, Fig. 2 twisted into spiral formation, such as showr at f, same figure, these spirals f being secured to circumferential members 9 (whicl may be plain round rods bent to shape] by welding at the junctions. As will b seen at Fig. 2 the reinforcement is embeddet in and covered over by the linin The pJrOcedure hereinbefore re erred to a applica 1e for concrete pipes would obvi ouslybe suitable for other hollow bodie made of concrete.

The bituminous composition made as here inbefore described is not an emulsion, but i a composition formed by the microscopic par t-icles of stone dust or flour, held in a stat of suspension in the water, constituting nu clei to and around which the bitumen whe it is introduced clin in such manner as t form a multitude o bitumen-stone glohule which, when the water is evaporated, autt matically adhere together and during th boiling process form a wet pasty mass. I this we the mass forms a bituminous-star composition to which water can be added 2 desired for thinning purposes.

As the composition dries and sets the b tuminous globules bind themselves togetht and seal and lose up the'pores left by tl tion while the concrete is still wet, continu ing the spinning of the body to distribute the bituminous composition over the interior surface of the body and thereafter allowing the concrete and bituminous composition to set simultaneously.

2. A process of making bituminously lined pipes or other hollow bodies of concrete con-' sisting in spinning a mass of concrete to form the body, introducing into the body while the concrete is still wet a quantity of cold, aqueous bituminous composition composed of a mixture of liquid bitumen with stone-flour and water, continuing the spinning of the body to distribute the bituminous composition over the interior surface of the body, and thereafter allowing the concrete and'bituminous composition to set simultaneousl and become dry and hard.

3. A process of makinv bituminously lined pipes or other hollow bo ies of concrete consisting in spinning a mass of concrete to form the body, mixing liquid bitumen with stone-flour and water in about the proportion of 18 pounds weight of bitumen to 48 pounds weight of stone-flour fluid, introducing a quantity of the said mixture into the concrete body while the latter is still wet, continuing the spinning of the body to distribute the bituminous mixture over the interior surface of the body, and thereafter allowing the concrete and the bituminous mixture to set simultaneously.

4. A process of making bituminously lined pipes or other hollow bodies of concrete consisting in s inning a mass of concrete to form the ha y, preparing a mixture of stoneflour and water, heating same to the boiling point, adding bitumen 1n 9. liquid condition, maintaining the mixture in a boilin condition until it assumes the form of a stiff paste, adding water to the mass and agitating till cool, introducing a quantity of the aforesaid cold, aqueous bituminous mixture into the concrete body while the latter is still wet,

continuing the spinning of the body to distribute the mixture over its interior surface, and thereafter allowing the concrete and the bituminous mixture to set simultaneously and become dry and hard.

5. A process of making bituminously lined pipes or other hollow bodies of concrete conisting in spinning a mass of concrete to form the body, introducing a quantity of cold,

aqueous, liquid bituminous composition while the concrete is still wet, continuing the spinning of the body to distribute the bituminous composition over the interior surface of the body, allowing the concrete and bituminous composition toset simultaneously, placing the hardened body on the spinning, machine, introducing a quantity of a hot non-aqueous bituminous composition, spinning the body to distribute same and thereafter cooling the body and lining, the lining applied cold serving as a key for the subsequent hot lining.

6. The process of makingbituminously lined pipes or other hollow bodies of concrete consisting in s inning a mass of concrete to formlthe bo y, preparing a mixture of stone-flour and water, heating same to the boiling point, adding bitumen in a liquid condition, maintaining the mixture in a boiling condition until it assumes the form of a stiff paste, adding water to the mass and agitating till cool, introducing a quantity of the aforesaid cold, aqueous bituminous mixture into the concrete body while the latter is still wet, continuing the spinning of the body to distribute the mixture over its interior surface, allowing the concrete and the bituminous mixture therein to set simultaneously, again placing the hardened body on the spinning machine, introducing a quantity of a hot non-aqueous bituminous composition, spinning the body to distribute same and until the hot bituminous compo sition within the body is cold and hard and has firmly adhered to the first applied bituminous composition and forms a hard black and glossy lining.

7. A process of making bituminously lined pipes or other hollow bodies of concrete consisting in spinning a mass of concrete-to form the body, introducing a quantity. of

cold, liquid, bituminous composition while the concrete is still wet, continuing the spinning of the body to distribute the cold bituminous composition over the interior surface of the body, allowing the concrete and the bituminous composition to set simultaneously, inserting a cylindrical reinforcement into the body, again placin the hardened body on the spinning mac ine, intros ducing a quantity of a hot non-aqueous bituminous composition, spinning the body to distribute same over the reinforcement and until the hot bimninous composition within the body is cold and hard and has firmly adhered to the first ap lied bituminous comosition and forms a I ard black and glossy ining.

8. A process of making bituminously lined pipes or other hollow bodies of concrete consistin in spinning a mass of concrete to form the ody, preparing a mixture of stone- 'flour and water heatin same to the boiling point, adding bitumen m a liquid condition,

maintaining the mixture in a boiling condition until it assumes the form of a stiff paste, adding Water to the mass and agitating till cool, introducing a quantity of the aforesaid cold bituminous mixture into the concrete body while the latter is still wet, continuing hard and has firmly adhered to the first applied bituminous composition and forms a hard black and glossy lining.

9. A bituminously lined pipe made by spinning a mass of concrete to form the pipe, introducing a quantity of cold, aqueous, liquid bituminous composition while the concrete is still wet, continuing the spinning of the pipe to distribute the bituminous comosition over the interior surface of the pipe and thereafter allowing the concrete and bituminous composition to set simultaneously.

10. A bituminouslylined pipe made by spinning a mass of concrete to form the pipe, introducing a quantity of cold and aqueous liquid. bituminous composition while the concrete is still wet, continuing the spinning hardened body on the spinning machine, in-' troducing a quantity of a hot nonaqueous bituminous composition, spinning the pipe to distribute same and thereafter cooling the pipe and lining, with water or otherwise, the lining applied cold serving as a key for the subsequent hot lining.

11. A bituminously lined pipe made by spinning a mass of concrete to form the pipe, introducing a quantity of cold aqueous and liquid bituminous composition while the concrete is still wet, continuing the spinning of the pipe to distribute the cold bituminous composition over the interior surface of the pipe, allowing the concrete and the bitu minous composition to set simultaneously, inserting a cylindrical. reinforcement into the pipe, again placing the hardened pipe on the spinning machine, introducing a quantity of a hot non-aqueous .bituminous composition, spinnin the pipe to distribute same over the reinforcement and until the hot bituminous composition within the body is cold and hard and has firmly adhered to the first applied bituminous composition and forms a hard black and lossy lining.

In testimony whereof aflix my signature.

ROBERT ILLEMANN.

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