Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C19/00—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving
  • E01C19/02—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving for preparing the materials
  • E01C19/10—Apparatus or plants for premixing or precoating aggregate or fillers with non-hydraulic binders, e.g. with bitumen, with resins, i.e. producing mixtures or coating aggregates otherwise than by penetrating or surface dressing; Apparatus for premixing non-hydraulic mixtures prior to placing or for reconditioning salvaged non-hydraulic compositions
  • E01C19/1059—Controlling the operations; Devices solely for supplying or proportioning the ingredients
  • E01C19/1068—Supplying or proportioning the ingredients
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L95/00—Compositions of bituminous materials, e.g. asphalt, tar, pitch
  • C08L95/005—Aqueous compositions, e.g. emulsions
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C7/00—Coherent pavings made in situ
  • E01C7/08—Coherent pavings made in situ made of road-metal and binders
  • E01C7/18—Coherent pavings made in situ made of road-metal and binders of road-metal and bituminous binders

Definitions

• a method of preparing and producing asphalt materials to be laid out as a cold road construction or paving material is a method of preparing and producing asphalt materials to be laid out as a cold road construction or paving material.
• the present invention relates to a method of cold produc- tion of asphalt materials for a cold laying out as a road building or repair material.
• This 'hot' method has noticeable limitations and drawbacks, not only with respect to the high heat con ⁇ sumption and the large investment costs, but also in that the method should be seen as a totality in connection with a given paving work. Since the material cannot be satisfacto ⁇ rily laid out and compressed if the transportation distance from the factory to the working site or the waiting time at the laying site is so long that the material is cooled sub- stantially, the method is sensitive to transportation dis ⁇ tance as well as to irregularities in the laying rhythm.
• the method is very sensitive to variations in the laying rhythm, i.e. there will be severe risks that an already prepared material charge becomes unusable due to the breaking of the emulsion taking place too early or too late.
• An early breaking implies that the material conglutinates prior to the laying out, whereby it may be difficult or im- possible to lay the material in a satisfactory manner; by a late breaking, by which the material will be shapeable during the laying out, the laid out material, until the breaking oc ⁇ curs, will be unstable in response to mechanical influence, causing deformation of the material layer, and to rain water, which will act to wash out the unbroken emulsion, whereby the final binding will be inferior to the expected result.
• the "material” is to be understood as two or at least two material fractions, which are prepared with latent breaking agents that will, each, be activated by a mixing together with the other fraction, but otherwise leaving the material fraction with the binder emul ⁇ sion in a time non-determined, non-actuated condition.
• latent breaking agents that will, each, be activated by a mixing together with the other fraction, but otherwise leaving the material fraction with the binder emul ⁇ sion in a time non-determined, non-actuated condition.
• this may be easily realised in preparing, for later mixing together, two separate material fractions with binder emulsions of anionic and cationic type, respectively.
• binder emulsions may each be adapted to be, over time, practically unlimited actuatable, also so as to not break by the mixing together with the associated stone fraction, and each of the two material fractions may thus be produced to stock, when only they are kept strictly separate. It is then possible at any time to collect from the stock re ⁇ spective portions of the two types, which, upon a mixing to ⁇ gether that need not be very intensive, may be brought to laying out whether in connection with larger construction or renovation works or with more isolated repair works.
• the new technique will imply that the asphalt plants are free to run a production to stock, which can be done by an even production such that the produc ⁇ tion capacity can be adjusted to an average consumption and not to an acute maximum consumption during separate periods of time, this implying a much more economic production.
• mixing facilities should be at disposal, operable with a capacity as required during periods with high consumption of the material to be laid out, but this equipment may be rather simple; it should be able to effect a mixing, but the mixing need not be particularly in ⁇ tensive or uniform, because in the laid out material a cer ⁇ tain migration of the anionic and cationic emulsions will oc ⁇ cur.
• the asphalt plant should not nec ⁇ essarily be equipped with a conventional compulsive mixing equipment, since for both types of material it will be suffi ⁇ cient to effect a spraying dosing of the emulsion e.g. on a falling flow of the stone material; when the material is thereafter stocked without any breaking of the emulsion, the emulsion may then, gradually, distribute itself over the sur ⁇ face portions of the stones that might be left uncoated by the spraying, such that the stones may nevertheless be fully coated when the time comes to mix the two types of material. This conditions a significant cost saving in processing equipment and labour in the asphalt plants.
• the stone material will normally include a fine fraction such as sand, and when the material is processed as here described the fine fraction will tend to be preferentially coated. For this reason it may be preferred to effect a conventional homogenous mixing of the respective material types, unless the different fractions are processed individually.
• the emulsions are liable to un ⁇ dergo some degree of breaking as a result of their contacting the stone material.
• Such a partial breaking which leaves the material fully shapeable, has the advantage of ensuring that the stones are durably coated with a cohesive and adhesive layer of binder.
• the collection of the material from the stock or the storing places can be supple- mented by a delivery of the material directly from the pro ⁇ cessing equipment of the asphalt plant, inasfar as both of the material types may be equally usable after storing and immediately after being prepared.
• the types of material may occur as packed in sacks, whereby they can be mixed to form very small total portions for execution of pro ⁇ nounced small jobs, this so for not having been a realistic possibility.
• the invention may provide for the option of the two types of material to be sold as sacked products in various building markets and yet still be applicable for ad ⁇ vanced laying out at a large scale.
• precoated stones i.e. stones prepared with a coating of bitumen by a cold or hot process.
• various ad ⁇ ditives may be used, e.g. some polymers or fibre material that will stabilise the water against breaking of the emulsi ⁇ on.
• solvents may be entirely avoided.
• a noticeable mixing of the emulsions or polymer modified bituminous emulsions will occur immediately by the bringing together of the two material types as well as by the compres ⁇ sion that is normally effected just after the laying out, and in most cases the road will be ready to receive both traffic and rain water as soon as the laying out and the mechanical aftertreatment is finished.
• the breaking and the binding oc- cur from the very beginning all over the material, from bot ⁇ tom to top, but the conditions can be controlled such that the material remains shapeable during the laying out. It should be mentioned that for just this reason it will be worth endeavouring that the preceding mixing operation should not be particularly efficient, whereby the mixing will be that much simpler to carry out.
• the invention will be well suited for treatment and utilisation of recycled asphalt, which will typically hold 4- 6% bituminous binder with good adhesion to the stones.
• the material is re-worked by an addition of a few percent of ad ⁇ ditional binder in emulsified form, whereafter the material or the respective material types will be ready for a cold laying out whenever required.
• the two types of material should not necessarily be mixed in the ratio 1:1, as in general terms they should only be mixed in a ratio such that the associated and desired pH-ad- justment for actuation of the emulsion breaking will be ob- tained. If one emulsion is more acid than the other is basic, then it is relevant to use a relatively smaller amount of the acid fraction.
• the invention is extended to the use of con ⁇ tra-polar emulsions or agents which, breakingwise, will actu- ate each other when being mixed together, but otherwise being substantially non-breaking or at least non-breaking through a desired period of time, ranging from few hours to several years.
• This result is achievable by the use of the respective anionic and cationic emulsions, but probably it can be achieved also by means of other 'contra-polar systems' such as different, but mutually miscible liquids or solids in liq ⁇ uids or colloidal suspension or gells.
• bituminous binders in the respective emulsions are not of the same viscosity or rheology and may be hydro ⁇ carbon binders or bitumens modified by polymers or additives, or unmodified binders with or without additives such as sil ⁇ ica fume or filler or fibres or carbon black or adhesion agents;
• bituminous emulsions are both cationic or both anionic or non-ionic or combinations such that the two sepa ⁇ rately coated material fractions when mixed together act as breaking agents for each other, either as PH modifiers or as buffers or as destabilising chemical reaction initiators;
• bituminous or hydrocarbon binders in the res ⁇ pective emulsions react with each other after coalescence or cross-link upon contact such that a higher cohesion or vis ⁇ cosity results, with the benefit of enhanced properties of the mixture of two material fraction
• the stone material may consist of pre-coated fines an uncoated coarse particles or pre-coated coarse particles and uncoated fines or blend of both or totally pre-coated ma ⁇ terial by methods including the use of bituminous and hydro ⁇ carbon emulsions, foamed bituminous or hydrocarbon of any po ⁇ larity, hot coating or any combination of these;
• the prepared material fractions may consist of more than two separate fractions and can be composed of fines or coarse fractions in any ratio such that when homogeneously mixed together the desired aggregate grating curve is formed;
• the emulsion system may include a two component epoxy resin bitumen blend or polyurethane system as two sepa- rate emulsion systems made to break each other.
• the bitumen in the emulsions may be of any viscosity, as suitable for respective applications; there is no upper limit, so viscosities of e.g. 200,000 og 500,000
• A 70% anionic emulsion based on B180 produced in accordance with ASTM class SS.
• B 70% cationic emulsion based on B180 produced in accordance with ASTM class CSS.
• A 70% anionic emulsion based on B80 produced in accordance with ASTM class MS.
• B 70% cationic emulsion based on B80 produced in accordance with ASTM class CMS.
• A 70% anionic emulsion based on B180 produced in accordance with ASTM class SS.
• B 70% cationic emulsion based on B180 produced in accordance with ASTM class CSS.
• Emulsions A: 50% anionic emulsion based on B180 produced in accordance with ASTM class SS.
• B 50% cationic emulsion based on B180 produced in accordance with ASTM class CSS.
• the material is hereafter treated as in example 3. Sacked materials for reinstatement purposes.
• the aggregate is precoated with 1.5% B80.
• A 70% anionic emulsion based on B180 produced in accordance with ASTM class SS.
• B 70% cationic emulsion based on B180 produced in accordance with ASTM class CSS.
• the mixtures can be sacked in strong plastic sacks marked with an A for the anionic mixture and a C for the cationic mixture.

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• Engineering & Computer Science (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Architecture (AREA)
• Health & Medical Sciences (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Road Paving Structures (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 1995
  • 1995-05-24 DK DK060095A patent/DK60095A/da not_active Application Discontinuation
• 1996
  • 1996-05-24 WO PCT/DK1996/000224 patent/WO1996037660A1/en not_active Application Discontinuation
  • 1996-05-24 CA CA002222072A patent/CA2222072A1/en not_active Abandoned
  • 1996-05-24 EP EP96916016A patent/EP0828895A1/en not_active Withdrawn
  • 1996-05-24 AU AU58930/96A patent/AU698694B2/en not_active Ceased
• 1997
  • 1997-11-24 NO NO975395A patent/NO975395L/no unknown

Non-Patent Citations (1)

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