JPS6017313B2 - Paving composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This application is open graded.
d) It relates to an emulsified asphalt pavement, the composition used to produce it and the method for its production.

Open graded pavements are generally defined in pavement technology as aggregate or asphalt mixtures with a high void content.

Pavements are made from hot asphalt mixtures or asphalt emulsions. These have the property of being relatively low cost and allowing water to drain through the pavement structure. This latter characteristic is due to the fact that this pavement is used as a cover over existing expressways to prevent ``hydroplaning'', a phenomenon caused by water dampness that occurs between smooth pavement and tire surfaces. is particularly suitable. Open graded emulsified asphalt pavements are of particular interest in locations far from factories where hot asphalt mixtures are available.

Through the use of emulsified asphalt, compounding of the emulsion and aggregate can be carried out in compounding equipment that is easily assembled in remote areas. However, using emulsified asphalt to construct open graded pavements poses several problems.

The porosity of this mixture precludes the use of conventional slow setting emulsions (type SS). In such a case,
Before curing occurs, a significant amount of emulsion is washed away from the structure and asphalt loss occurs. If the pavement is exposed to rain before curing is complete, even more of the asphalt will be washed away from the pavement. Both washing away and washing can reduce the strength of the pavement and cause environmental pollution. Therefore, to alleviate these problems, the emulsions used in these applications are designed to "break" when mixed with aggregates.
It was a medium-speed curing type (MS type) with a low degree of stabilization, which was designed to have a high degree of stability. In most cases, this result is due to the fact that the mixture contains a significant amount (5 to 15%, usually 8 to 10% by weight of milky fluid).
This can be improved by adding petroleum naphtha. This results in softening of the asphalt, resulting in better coverage and adhesion. However, the use of naphtha introduces new problems. First, the use of naphtha increases costs. Because naphtha is easily lost to the atmosphere through evaporation. Second, naphtha evaporation can cause air pollution problems. Third, the risk of fire during operation increases. Fourth, naphtha softens the asphalt, so it takes a considerable amount of time for the pavement to reach sufficient strength, and if a heavy vehicle is driven on the pavement before it has reached sufficient strength, ruts may be left on the surface. Probably. It is therefore desirable to produce an open graded emulsified asphalt that exhibits good aggregate coverage properties and has the desired washout characteristics without the use of naphtha, and to create a pavement that rapidly gains sufficient strength. . Anionic polyelectrolytes, such as salts of synthetic polycarboxylic acids, have been disclosed as primary emulsifiers and emulsion stabilizers, if not specifically for bitumen.

Rohman and Haas
o. ) is used as an emulsifier and as an emulsion stabilizer for emulsions made with nonionic emulsifiers.
ACRYSO describes the use of neutralized acrylic polyacids commercially available under the name ``).
Cationic polyelectrolytes, such as grade salts, have also been disclosed for use as emulsion stabilizers and emulsifiers (Reference: 196g) Submitted to the 159th National ACS Meeting of the American Chemical Society on September 9th. Fred Hoover
r) paper “Intestinal Ionic Quaternary Polyelectrolytes - Literature Review”
electrolytes-ALiteratureR
“view”)].

The inventors have developed a novel method of using open graded bone marrow, ionic or anionic (i.e. ionic) emulsified asphalt, and a small amount of ionic polyelectrolyte with an opposite charge to the asphalt emulsifier. It has now been discovered that open graded emulsified asphalt pavements can be made from the mixture. These mixtures have excellent aggregate coverage, quickly reach maximum strength, and provide pavements with excellent water resistance (scouring resistance and low runoff) even in the absence of petroleum naphtha. Both highly ionic emulsified asphalts containing small amounts of anionic polyelectrolytes and anionic emulsifying asphalts containing small amounts of cationic polyelectrolytes are contemplated. In a preferred embodiment, the polyelectrolyte is generated in situ.

That is, an anionic polyelectrolyte is produced by basifying an emulsion containing a small amount of a polymeric multiple acid, which is a polyelectrolyte precursor (PEP). These open
The graded emulsified asphalt mixture is applied in several ways: [11] The polyelectrolyte can be added to the emulsion and the mixture stored for a relatively short period of time, up to 4 hours.

In some special cases, the mixture can be stored for as long as 10 hours. The emulsion is then mixed with aggregate immediately before application to the road bed or road surface. This method, like all other methods, provides sufficient processing time for the mixture to allow processing (sparing, etc.) of the mixture before it hardens. ■ The aggregate may be pretreated with polyelectrolytes, immediately prior to application of the emulsion mixture with the aggregate.

'3} The aggregate, emulsion and polyelectrolyte can be mixed all at once just before application. Regarding the intestinal ionic emulsion alone, the following two methods can also be used.

[41] PEP can be used to pre-treat with bone marrow.

An emulsion that is sufficiently basic to convert the PEP into a polyelectrolyte form can then be mixed with the aggregate.
{51 The aggregate, PEP and emulsion may be mixed together and the mixture is made basic by mixing with sufficient base to neutralize the precursor before use.

'61 A preferred method is to add PEP to the emulsion and mix the emulsion with the aggregate and base before use.

In this case, the emulsion containing PEP can be stored for a long period of time. One preferred type of asphalt emulsion is prepared with enteric ionic emulsifiers.

Included in this emulsifier are U.S. Pat.
No. 445,258. Suitable enteric-ionic emulsifiers capable of emulsifying bitumen in water include enteric-active salts of quaternary nitrogenous bases, salts of aliphatic amines, preferably linear primary aliphatic mono- and diamines, amidoamine salts, e.g. Any of the following may be used, including amidoamine hydrochloride of stearic acid and others, hydrohalide salts of amide/amides of polyalkylene polyamines such as tetraethylenebentamine and fatty acids, and others. Other classes of suitable emulsifiers include salts of ethylene oxide adducts of aliphatic diamines and ethylene oxide adducts of hydrocarbon-substituted imidazolines. The above examples are of course illustrative and not all-inclusive. The use of mixtures of various enteric ionic emulsifiers is also contemplated. Preferred cationic emulsifiers are those described as salts of quaternary nitrogen bases disclosed in US Pat. No. 3,220,953. These compounds have the desired general formula (where R1, R2, R3 and R4 are each an organic group having a carbon-nitrogen bond to the nitrogen atom, X is an anion with a valency not exceeding 2, and m and n are small integers indicating the molar proportions of enteric ions and anions necessary to form the salt in question.

Preferred emulsifying salts are those in which the organic groups R1, R2, R3 and R4 are alkyl, alkenyl, hydroxyalkyl, arylalkyl or alkylaryl groups of 1 to 24 carbon atoms, or solids of 4 to 1 carbon atoms. is a polycyclic group in which 2 to 3 nitrogen valences are shared by two carbon atoms in a single heterocyclic group. For all of these salts of quaternary nitrogenous bases suitable for use as enteric ionic emulsifiers in the production of oil-in-water milk sardine fluids, the number of accumulated carbon atoms in the cationic part of the molecule (num in the key rega) The wide r) should be large enough to provide oil solubility and emulsifying properties, and preferably equal to 15 and 1 carbon atoms.
It should be 4 times smaller than 5 and not larger than 30.
In other words, this class of cationic quaternary nitrogen-containing compounds can be prepared by salts of tetrasubstituted ammonium bases and by dicyclic nitrogen bases such as pyridinium, quinolinium, inquinolinium, morpholinium, piperazinium, imidazolinium, and Produced by salts of other quaternary nitrogenous bases. The anion may be halide (X-), methosulfate (SQCH3-), nitrate (N03-) or similar ions.

Preference is given to monovalent anions, especially halide anions.

A number of highly ionic quaternary nitrogen-containing emulsifiers can be used in the preparation of anionic oil-in-water emulsions.

A few of these are as follows: N.N-dimethyl-N-benzyl-N-octadecylammonium chloride.

Ride N・N-dimethyl-N-hydroxyethyl-N-
Dodecylammonium chloride N・N-dimethyl-N
-Benzyl-N-octadecenylammonium chloride N.N-dimethyl-N-penzyl-Ndodecylammonium chloride N.N-dimethyl-N-hydroxyethyl-N-pendylammonium chloride Hexadecylpyridinium bromide Hexadecyltriethylammonium bromide Octadecylbenzyltrimethylammonium metasulfate isopropylnaphthyltrimethylammoniumc.

Ride octadecylpyridinium bromide 1-(2-hydroxyethyl)-2-heptadecenyl-1-(4-chlorobutyl) imidazolinium chloride hexadecylmethyl piberidinium methosulfate dodecyl hydroxyethyl morpholinium bromide oil-in-water type Among the commercially available quaternary nitrogen-containing substances as enteric ionic emulsifiers for the preparation of emulsions are those sold by General Mills under the trade name "ALlQUAr'"; Quaternary ammonium halide material; some product names are ``ARQUAD'') manufactured by Armac Corporation (~m
akCompany): Some substances sold under the trade name ``SAPAMINE'' by the Society of Chemical Industry (SMiety of Chem, Basel, Switzerland).
There are several quaternary substances developed and marketed by the International Chemical Industry Association (Chemical Industry Association), and many others.

The active cationic component of these materials includes the following characteristic positively charged quaternary nitrogen configuration: where R
The concentration of carbon atoms of 1, R2, R3 and R4 is sufficient to provide oil solubility and emulsifying properties and is not less than or equal to 15 and not more than 30 carbon atoms.

Those in which the active cationic component falls within the above-mentioned quaternary nitrogen-containing substances containing at least one long aliphatic hydrocarbon having less than 12 and not more than 24 carbon atoms, such as an alkyl or alkenyl chain. The best emulsification can be achieved by

The above chains can be derived from mixtures of organic materials such as tallow, soybean oil, lard, and others. The emulsifier material may consist solely of active cationic salts of quaternary nitrogen bases or may also contain some impurities such as acyl chlorides and amines. It may be used in the form of a concentrated aqueous solution and may contain supplementary stabilizers in amounts conventionally used in the art. Among the commercially available emulsifier substances of this type, the following can be used for the preparation of the cationic emulsions according to the invention: [1} / HYAM
INE) 2 papers 9.

N-alkylmethylbenzyl-N.N-trimethylammonium chloride' having the formula:
The product name of the product (mpany) is:
ARQUAD)T. This is a C,4-C, having the following formula, where R is a long mirror alkyl derived from beef tallow.
8 Alkyltrimethylammonium chloride' is the trade name for a product manufactured by the Mak Company of Chicago, Illinois: [3'/-Iamine 162] This is diisobutylphenoxyethoxy with the general formula: All products from Rohm and Haas Chemical Co., Philadelphia, Pennsylvania, for ethyldimethylbenzylammonium chloride mono/hydrate: [CH3.C(CH3)2.C(CH3)]
2・C Rainbow 5・OCQCH2・OCH2CH2N (C ratio)
2.CQC 6th day 5] 10CI-{41 Arkatsudo S.

It has the formula below where R is a long chain alkyl derived from soybean oil. C,6-C,8 alkylmethylammonium chloride is the trade name of a product manufactured by Armac, Inc. of Chicago, Illinois. It is believed that small amounts of starting materials are normally present in the emulsifiers mentioned above as impurities which have no effect on the usability of the emulsifiers according to the invention.

These and other suitable enteric ionic emulsifiers generally contain from about 0.25 to about 5%, preferably from about 0.40 to about 2%, of the active enteric ionic component, based on the weight of the finished emulsion. Higher or lower amounts may be used depending on factors such as the cost of the emulsifier, the effectiveness of the emulsifier, the richness of the bitumen to be dispersed, and others.

The asphalt will be present in the emulsion in an amount of about 40 to 7 and preferably 60 to 7 percent by weight of the emulsion. The remainder of the emulsion is 100% water. Other types of suitable asphalt emulsions are prepared with anionic emulsifiers. Among these are those described in Canadian Patent No. 812658, British Patent No. 864102; There's something in there. Any suitable anionic emulsifier capable of emulsifying pitumen in water can be used, including alkali metal sulfonic acids and carboxylic acids. Carboxylic acid emulsifiers include fatty acids, naphthenic acids,
and cresylic acid salts.

These salts are usually made from alkali metals, and sodium is the preferred metal. Carboxylic acid salts are preferred. Other carboxylic acid emulsifiers include tall oil acid, rosin acid,
Contains salts of fatty acid pitch (leftover from fatty acid distillation) and pine chip resin extract.

This last is the preferred carboxylic acid emulsifier. Sulfonic acids used to form the anionic emulsions include alkylaryl sulfonates with molecular weights from 400 to 500, such as pis(dodecylbenyl)ether disulfonic acid, octadecylbenzenesulfonic acid, polypropylenebenzenesulfonic acid, There are fonic acids, dioctylbenzenesulfonic acids and others.

All of the above acids are utilized as their alkali metal salts, preferably sodium salts. Naphthenic acids extracted from petroleum sources are good emulsifiers for this purpose.

The acid number of such naphthenic acids should be in the range from 75 to 175. Polyelectrolytes are well-known substances [Encyclopedia of Polymer Science and Technology].
PolymerScience and Technology
gy; Encyclopedia of Polymer Science and Technology) Part 1
Volume 0, pages 781-854].

In electrochemical terms, polyelectrolytes can be classified as polyacid, polybase or polyampholyte (Polyampho-1i). This application relates primarily to multiacid and multibase polyelectrolytes. Polyelectrolytes can be described as aqueous high molecular weight polymers or copolymers with ionizable substituents along the backbone chain. These ionizable groups may be anionic or cationic in nature. Suitable polyelectrolyte precursors (PEPs) are high molecular weight polymers or copolymers with anionic ionizable groups along the chain. These ionizable or acid groups are easily converted into ionizable groups by addition of a suitable base. These materials (polyelectrolytes and polyelectrolyte precursors may be natural or synthetic). The polymers used in this application are substantially linear (i.e., non-crosslinked). ) is preferred, but small amounts of cross-linking are acceptable as long as the polymer remains water-soluble. High molecular weight polymers and their precursors are typically
Average molecular weight (measured by gel permeation chromatography)
at least about 1000, preferably 10000 and 10
It may be a synthetic polymer with a size as large as 0,000,000. Anionic substituted ionizable groups may be salts of acidic groups attached to the polymer backbone, including, for example, carboxyl groups, sulfonic acid groups, phosphonic acid groups, and others.

Such acid groups may be directly bonded to a backbone carbon atom or may be attached to one or more connecting atoms such as oxygen or sulfur atoms.
, imi/group, polymethylene group, or a combination thereof. Examples of such types of linkages include monosulfate acid groups, monophosphate acid groups, methylene carboxylic acid groups, and the like.
Preferred ionizable and ionizable substituents are carboxylic acids and salts thereof. Usually there will be 2, preferably no more than 3, and about 3 solid carbon atoms per ionizable group. Thus, the polymeric monomer will normally have 3 to 3" hard carbon atoms and one or more acidic groups. Synthetic polymers and copolymers with ionizable or ionizable groups are useful for this purpose. The combination is easily made by polymerizing or copolymerizing appropriate monomers.

Preferably, the monomers consist of monosaturated compounds which undergo additional polymerization to form long chain linear polymers or copolymers. Addition of small amounts of disaturated or polysaturated compounds will cause small amounts of cross-linking. Non-crosslinked polyelectrolytes are preferred. Salts of ionizable groups and ionizable groups themselves can be prepared, for example, by hydrolyzing anhydrides, such as polymaleic anhydride, or by saponifying polyesters or polyamides, such as polymethacrylates or polyacrylamides, or by saponifying nitrile groups, such as polymaleic anhydride. It should be understood that by hydrolyzing acrylonitrile and others, polymers can be produced after they are manufactured.

Suitable acids or popntialacid-containing monomers for preparing homopolymers or copolymers for this use include acrylic acid, acrylamide, acrylonitrile methyl acrylate, Maleic anhydride, maleic acid, methacrylic acid, crotonic acid, allyloxyacetic acid, ethyl vinyl acetate, itaconic acid, citraconic anhydride, dimethyl fumarate, furfuryl acrylic acid, 5-norbornene-2-acrylic acid, N-vinylmaleic acid , vinyl adipic acid, p-styrene sulfonic acid, p-styrene sulfonic acid, ethylene sulfonic acid, allyl hydrogen sulfate,
Copolymerized with one or more acid-containing monomers such as those listed above, including allyl dihydrogen phosphate, allyl methyl hydrogen phosphate, p-vinyl phosphoric acid and the like, to form suitable polymers. Suitable acid-free monomers useful in forming the molecular electrolyte include methyl vinyl ether, methyl pinyl ketone, allyl ether, acrylonitrile, vinyl acetate, allyl methyl orthophthalate, vinyl octyl sulfide, ethylene. , propylene, styrene, p-methoxystyrene and others.

In addition, polymers with acid sulfate or acid phosphotionizable groups can also be prepared by sulfating or phosphorylating polypinyl alcohol with sulfuric or phosphoric acid.

Natural anionic polyelectrolytes useful in this method include:
Includes hydrolyzed yeast or gum arabic, lignin sulfonates, polymerized rosin acids, and others.

Protein polyelectrolytes including blood, casein, gelatin and others are also suitable. A preferred anionic polyelectrolyte is polyacrylate.

Suitable cationic substituted ionizable groups are amide/and salts of quaternary amino groups attached to the polymer backbone.

Upon dissolution in water, amines ionize by forming ammonium compounds with water. The substituent may be directly attached to the polymer backbone or may be a polymethylene group,
Linking groups such as carbonyl-containing groups, ether-containing groups, and aryl groups and the like
ting bait (up). Quaternary aminos/substituents are formed by adding sufficient halide- or sulfate-containing organic molecules to a primary, secondary or tertiary amino group, such that four groups are directly attached to each nitrogen atom. It is also created by converting most of the nitrogen to the tetravalent state so that each nitrogen atom has a net positive charge. Preferably, the quaternizing agent is methyl chloride.
Amino-containing polymers can be produced by homopolymerizing or copolymerizing unsaturated amino compounds.

Among such compounds are vinylamine, ethyleneimine, 4-vinylpyridine, 3-allylpyridine, N
-Allylpiveridine, allyldiethylamine, N・N-
Diethylaminoethyl acrylamide, N/N-dimethylaminoethyl methacrylic acid, vinylenediveridine, 2
-vinylguanidine, p-diethylaminoethoxyethyl methacrylate and others. Amine-containing polymers can also be prepared by aminomethylation, such as by reacting polyacrylamide with formaldehyde and dimethylamine. Suitable non-amine monomers useful for polymerization with one or more amine-containing compounds include methyl vinyl ether, methyl vinyl ketone, allyl ethyl ether,
Acrylonitrile, vinyl acetate, allyl methyl orthophthalate, ethylene, propylene, styrene, p
-methoxystyrene, and others.

Polyelectrolytes are used at concentrations effective to prevent runoff, usually
Based on the weight of the asphalt emulsion, approximately 0.01 L.
．． It will be used in the mixture at 0% by weight, preferably 0.05 to 1.0% by weight.

In preferred embodiments, the additive will be an anionic polyelectrolyte precursor when the emulsion is formed with a cationic emulsifier. This precursor would correspond to a polyelectrolyte, but would be a polymer containing acid groups that had not yet been neutralized. These materials are usually sold in the form of aqueous suspensions. An example of such a material is PrimafIM A-10, available from RohmaMHaas Co., Philadelphia, Pennsylvania. This material is described as an acid-containing polyacrylic acid emulsion polymer. This and other related products are said to be useful as emulsion stabilizers in combination with nonionic surfactants (primary emulsifiers). Asphalt emulsions are prepared in the manner customary for anionic or cationic bituminous emulsions. Therefore, for example, when preparing a cationic emulsion, the enteric ionic emulsifier is preferably used at a temperature of 100° to 12°C. It is first dissolved in water at a temperature of F. Thus, asphalt heated to 2400 to 28 F is dispersed in an aqueous solution obtained in a colloid mill. In this way, there is usually no 60,
The asphalt of 7 anchors is mixed with 30 to 4 anchor parts 1 of an aqueous solution containing a cationic emulsifier and optionally other additives.
Emulsified with a trowel. The emulsion may be used immediately or stored for later use. Anionic emulsions are prepared in the same manner using anionic emulsifiers. In a preferred embodiment, an appropriate amount of anionic polyelectrolyte precursor is added to the emulsifying water prior to the preparation of the enteric ionic emulsion.

In this form the emulsion can be stored for an extended period of time prior to use. The emulsion will be stable for several months. Therefore, at the time of application, a sufficient amount of base is usually added to the emulsion, greater than 7 and usually about 11
Greater pH is provided. In some cases, sufficient basicity is provided by the bone village to effect neutralization of the polyelectrolyte without the use of additional base. Such cases would normally be found with aggregates containing limestone. Any aggregate is suitable. Suitable bases therefore include a variety of organic and inorganic bases. Alkali metal bases are preferred. Particularly preferred is sodium hydroxide. Aggregates suitable for use with the emulsions of the present invention include a wide variety of citrus and calcareous materials.

As already mentioned, so-called open graded aggregates are preferred. Open graded asphalt mixture was manufactured in Moscow, Idaho, March 17, 1972.
cow)'s 23rd Annual Road Builders Clinic at the University of Idaho
dersClinic: Annual Meeting of Road Construction Contractors)
．． D. Design and Construction of Emulsified Asphalt Open Graded Mixture and Covering Submitted by Coyne
nofEmulsified Asphalt Ope
n Graded Mixes ando～erlay
ゞ) It is described inside.

Such mixtures have high porosity and usually contain fine aggregate (
sand) and an aggregate or asphalt mixture without mineral fillers. Federal Highway Administration, Region 10
ayAdministration, Regionlo
Emory Richardson (Emobi Richa)
rdson), W. He IJ Tudol (Liddie)'s "
Pacific Northwest Experience with Open Graded Emulsified Asphalt Paving”
riencemme Pacific Nor enemy Wes
t With 0pen Graded Emulsif
In addition, using asphalt emulsion, less than 10% of the pavement passes through No. Open graded asphalt pavement mixtures are specified that are characterized by the use of certain crushed stone or crushed gravel aggregates.A consistent aspect of almost all definitions regarding aggregates is that passing Section 200 is This means that it is less than %.

It is desirable that the bone village be relatively clean. Thus, the presence of a significant amount of finely divided powder will require a higher amount of emulsifier in the mixture. The mixture will contain about 3 to 2 weight percent emulsion based on the weight of the aggregate, preferably between 5 and 1 weight percent. Examples • The following examples illustrate the invention.

These examples are merely illustrative and not limiting. A specifically developed test was used to evaluate the coating ability as well as water resistance of emulsions used to produce open graded aggregate mixtures. This test is an ASTM
This is a modification of test method D-244. In this test, the following properties of the mixture are specifically measured: 1) Coverability, 2) Peeling resistance, 3) Washability, 4) Washability and workability (hardness). The test method is as follows: [11] 100 kg of open graded aggregate is placed in a mixing container.

'21 Wet the aggregate with water which may contain a base or polyelectrolyte.

■ Add the required amount of emulsion (72) to the aggregate.

'4' Mixture in Hobart Mixer
r) (using an "8" type blade), make a 19-stage light.
■ Record whether the emulsion is completely dispersed over the aggregate and whether spalling occurs (asphalt separating from the covered rock). Side Transfer the mixture to the blood with an opening on one side.

'71 Hold the plate and collect the emulsion flowing out from the opening.

By drying the spilled material, the amount of asphalt that is lost due to runoff is determined. '81 Take out a part of the mixture and estimate the ease of work. Refine this sample with cold water until the wash water becomes clear and flows out. ■ Estimate the percentage of asphalt coverage for the washed area and the total unwashed area, and take the difference as the "washing rate."

Example 1 This example illustrates the use of anionic polyelectrolytes in combination with enteric ionic asphalt emulsions.

The emulsion was made from 70/8 grade paving grade asphalt which was 65% by weight based on the total weight of the emulsion.
The emulsifier used was Arqad (Arq female d) T-50, which is a cationic quaternary as described above, and the emulsifier was
It was used at a concentration of % by weight. The polyelectrolyte to be tested was added to the aqueous solution prior to mixing with the emulsion. The total weight of water and polyelectrolyte was 2% by weight based on the aggregate. The polyelectrolyte used was as follows: {a'
Primafrock (Primaf) neutralized with NaOH
loc) - A-10 (already mentioned); [b' Dow Chemical's Purifloc -
A-23 Neutralized hydrolyzed polyacrylamide;'c
'Swift Chemical Company (SMftChemica)
lCo. ) flocculant (F1occulant)
X-400.

Table 1 below shows the results of the test.

Various aggregates were used. 9 for each
0% passed through the 3'8 inch wire mesh and was captured by No. 4, and 10% passed through No. 1 and was captured by No. 2. However, about 2% of fine powder passes through No. 20.
including gross-grade (tortoise oss-graded)
This does not apply to powder-containing limestone, which is limestone. Table 1: XRM=Easily Mixable MS=Moderately Hard It is also shown that the use of polyelectrolytes in the pretreatment of aggregates reduces the washout rate.

Example 2 In this example, an anionic polyelectrolyte precursor was roughly mixed with a cationic asphalt emulsion.

In the following tests, emulsions were prepared as in Example 1.

Add to this the above Primafrock A-10 (unneutralized)
0. % by weight of the box was added. 2% Na by weight based on aggregate
The aggregates were pre-wetted with OH solutions (with different baits). A 7% by weight emulsion was used.

The test results are shown in Table 2. Table 2 IRM = Easily Mixable MS〒 Moderate 2 Stored at Room Temperature 3140 Stored at 0F These data demonstrate that polyelectrolytes are activated by basic solutions, and that the more basic the better Show that.

Tests 5 and 6 tested the pH of the solution for certain aggregates.
The lower the value, the more effective activation occurs. 1400
Storage at high temperatures such as F does not compromise the effectiveness of this method.

Example 3 Open graded silica was tested by varying the concentrations of the ionic emulsifier (Arcad T-50) and polyelectrolyte precursor (Primafloc A-10) and the pH of the prewetting solution.

Polyelectrolyte precursors were added to water along with a cationic emulsifier prior to making the emulsion. Asphalt is example 1.
and of the same kind as in Example 2. The results are shown in Table 3 below. In addition to these days, emulsions made with polyelectrolyte precursors present in emulsifying water were prepared using pHil. It is shown that when contacted with aggregate pre-wetted with the pre-wetting fluid of No. 5, scour is avoided and the water resistance of the coating is improved.

In this case, hardening occurs for a prewetting solution with a pH of 11.5, whereas for the emulsion of Example 2, where the polyelectrolyte precursor is added to the emulsion after conditioning, a solution with a pH of 11.5 Note that the solution could not cause curing and a pH 12 solution was required. Example 4 A cationic polyelectrolyte was used in this test along with an anionic asphalt emulsion.

An emulsion was prepared as in Example 1, except that 0.3% VinsoIResin (Hercules (H)) in dilute sodium hydroxide solution was used as the emulsifier.
ercyama es) Inc. ] was used. The procedures adopted were those already described in these examples. A formulation was prepared using the above anionic emulsion to which the cationic polyelectrolyte Purifloc C-31 (Dow Chemical Company) was added.

Purifloc C-31 is a high molecular weight, water-soluble, synthetic cationic polyelectrolyte with the approximate structure:
The results are shown in Table 4 below.

Table 4 These data show that when no polyelectrolytes are included, the latex fluid is easily washed away from the stone and therefore has a high washout rate.

When containing polyelectrolytes, the water resistance of the mixture was significantly improved and wash-off was avoided. EXAMPLE 5 A number of other available anionic as well as cationic polyelectrolytes were tested for oppositely charged asphalt emulsions.

The test method is the same as already described. Table 5 below shows the properties of the emulsion, the properties of the commercial polyelectrolyte as well as the results obtained. Although the chemical composition of the polyelectrolytes has not been confirmed in detail by the manufacturer, the following results indicate that beneficial results are obtained when adding ionic polyelectrolytes to asphalt emulsions with opposite charges. Let me illustrate this. Various cationic polyelectrolytes were evaluated in combination with anionic emulsions prepared with 0.3% Pinsol resin according to the procedure of Example 1. The bone aggregate used was open graded silica aggregate. The data are shown in Table 5. Table 5: When tested according to the procedure already described, oaf.

Graded Watson Beer (
Watsonville) Enteric ionic emulsions prepared with 1.0% Alkad T-50 emulsifier and Various anionic polyelectrolytes were evaluated in combination. The results are shown in Table 6. As will be apparent to those skilled in the art, in light of the above disclosure and discussion, there may be other uses to the present invention without departing from the spirit or scope of this disclosure or from the scope of the claims herein. It is possible to make various modifications.

Claims (1)

[Scope of Claims] 1. A paving composition comprising 80-97% by weight of open graded aggregate and 3-20% by weight of a cationic or anionic bitumen emulsion, the emulsion comprising: The liquid contains about 40-75% by weight of asphalt based on the emulsion, 0.25-5.0% by weight of the emulsion of an emulsifier selected from the group consisting of cationic and anionic emulsifiers, and 100% by weight of the emulsion. % of water as the continuous phase of the emulsion, and the composition includes an ionic polyelectrolyte having an ionic charge opposite to the selected emulsifying agent to the emulsion of 0.01%. A paving composition characterized by containing ~3.0% by weight. 2 The polymer electrolyte has a molecular weight of approximately 10,000 to 100,000
00. 3. The composition of item 1 above, wherein the emulsion and emulsifier are cationic and the polyelectrolyte is anionic. 4. The composition of item 3 above, wherein the cationic emulsifier is a salt of a quaternary nitrogen base. 5. The composition of item 4 above, wherein the cationic emulsifier is C_1_4 to C_1_8 alkyltrimethylammonium chloride. 6 Polyelectrolyte has an average molecular weight of approximately 10,000 to 1,000
The composition of item 3 above, which is a salt of a polycarboxylic acid of 0,000. 7. The composition of item 6 above, wherein the polymer electrolyte is a synthetic polymer produced from a monomer having 3 to 30 carbon atoms. 8. No. 6 above, wherein the polymer electrolyte is a salt of polyacrylic acid.
composition of the term. 9. The composition of item 1 above, wherein the polyelectrolyte is generated in situ by neutralization of its precursor. 10. The composition of item 9 above, wherein the polymer electrolyte precursor is polyacrylic acid. 11. The composition of item 1 above, wherein the emulsion and emulsifier are anionic and the polymer electrolyte is cationic. 12. The composition according to item 10 above, wherein the cationic electrolyte contains, as an ionizable group, an amino group bonded to the backbone of the polymer or a salt of a quaternized amino group. 13 A method in which a polyelectrolyte precursor is added together with an emulsifier to the water used to emulsify asphalt, and this emulsion is combined with aggregate, in order to promote the hardening of the paving mixture to the aggregate. The composition of item 1 above, which is produced by a method in which the polyelectrolyte precursor contains sufficient base to neutralize the polyelectrolyte precursor. 14. The composition according to item 1 above, which is produced by a method of adding a polymer electrolyte to an emulsion. 15. The composition of item 1 above, which is produced by a method in which the aggregate is pretreated with a polyelectrolyte prior to mixing with the emulsion. 16. The composition according to item 1 above, which is produced by a method of simultaneously mixing aggregate, emulsion, and polyelectrolyte. 17. The composition according to item 1 above, which is produced by a method of pretreating aggregate with a polymer electrolyte precursor and mixing a basic emulsion with the pretreated aggregate. 18. The composition of item 1 above, which is produced by a method of simultaneously mixing aggregate, polyelectrolyte precursor and cationic emulsion with each other and adding sufficient base to neutralize the precursor. thing.