SI8911315A - Multi purpose asphalt binded product and process thereof - Google Patents

Abstract

Gel asphalt binder with improved ones is shown properties compared to conventional asphalt binder, which includes such a reduced temperature sensitivity as well as lower speed of aging hardening. This multipurpose asphalt binder is made with gelling liquid asphalt material. We achieve this with soaping in the melted asphalt, which is basically without water, at least one fatty acid and at least one of resin acid with alkali metal base or by addition of already saponified product into molten asphalt. The resulting gelled asphalt binder is useful in the usual procedures for paving roads, roofs and for special applications. Asphalt binder can be prepared and used using conventional mixing procedures hot asphalt mixtures in a given hot mixer, standard for roof and fixture use for special use of asphalt.

Description

ASPHALT MATERIALS, Inc.

Multipurpose asphalt binder product and process

The present invention relates to a new multipurpose asphalt binder and to a process for its production. It also refers to the use of this new product as a favorable substitute for conventional asphalt binders in road construction and roofing and as a new asphalt binder, with reduced temperature sensitivity and reduced curing time among the most important features.

Asphalt paving is used in over 90% of the US road surface. Natural asphalt, obtained from the bottom of lakes, was used as early as 1874. Later, natural crushed asphalt was found in the southern and western countries and laid on the ground, milled and rolled to form a road surface. Since the early 1900s, asphalt has been dominant, produced through the refining of oil and used in road and roof construction.

Asphalt is a dark brown, highly viscous material that contains bitumen as the main constituent found in most crude oil. Asphalt residues from petroleum refining, which are essentially free of light fractions, have the common name of asphalt.

Road paving asphalt is classified as an asphalt binder, diluted asphalt and asphalt emulsion. In our case, the asphalt binder is the most important, although emulsions and diluted asphalt are also useful for the future.

Asphalt binder is asphalt that has properties favorable for use in road construction or roofing and for new products. For road construction, the asphalt is heated to become free-flowing, mixed with an aggregate heated to approximately the same temperature (usually from 121 ° C to 177 ° C) and applied to the prepared surface, compacted and compressed to form asphalt concrete. In the long history of making asphalt pavements, mixing a hot mixture of asphalt binder and aggregate has remained a process that gives the best balance between price and quality.

In the hot mix process, the heated liquid asphalt binder is contacted with the heated aggregate to obtain a coated aggregate ready for application and compaction.

Asphalt binders used for roads are classified according to three parameters: viscosity, viscosity after aging and penetration. The most commonly used grading system in the US is based on viscosity measured in pores at 140 ° F (60 ° C) (AASHTO M-226) (AASHTO is a designation for the American Association of State Highway and Transportation Officials).

Below, all viscosity units are listed in Pa.s and temperatures in ° C, which is in accordance with the units permitted by Slovenian law.

Thus, an asphalt binder with a viscosity of 25 Pa.s at 60 ° C has the designation AC-2.5 and is considered as soft asphalt. An asphalt binder having a viscosity of 400 Pa.s at 60 ° C is known as AC-40 and is considered as hard asphalt. Intermediate asphalts, however, are designated as: AC-5, AC-10, AC-20 and AC-30 and are similar in relation to their viscosity. In addition, the AC50 is used in some areas with warmer climates, and the AC-1 in some areas with cooler ones. The standard types of asphalt are explained and tabulated in the Principles of Construction of Hot-Mix Asphalt Pavements, The Asphalt Institute, Manual ser. no. 22 (MS-22), January 1983, p. 14.

Some Western countries have a classification system based on viscosity after aging. The purpose of this system is to display the exact viscosity characteristics of road pavements after they have been applied. The test simulates the aging of asphalt by accelerating the oxidation of a thin layer of asphalt at 60 ° C (AASHTO M-226). The results show that, with respect to AR-10, asphalt with a viscosity of 100 Pa.s is considered to be soft and AR-160 asphalt with a viscosity of 1600 Pa.s is considered to be hard. This classification system is explained in the above-mentioned publication on page 15.

Asphalt can also be classified by the standard penetration test (AASHTO M-20). In these tests, the penetration depth (distance) of a standard needle with a specific load on the asphalt at a given time at 25 ° C indicates the hardness or softness of the asphalt. This test is explained in the above publication on page 16.

When covering roofs, the asphalt binder is used in the manufacture of multi-layer roofs, shingles and as an impregnating agent for rolled asphalt roofs. The asphalt binder used in multi-layer roofs is classified according to the softening point according to ASTM D313. (ASTM stands for American Society for Testing Materials). Type I asphalt having a low softening point is considered as soft asphalt. Type IV roof asphalt has a high softening point and is considered as hard asphalt. These and intermediate types are based on the sensitivity of the asphalt to flow at the indicated temperatures and gradients. Multilayered roofs are made by rolling asphalt impregnated felt onto which the asphalt binder is applied. Repeat this process several times to get a multi-ply roof.

There are other specific uses of asphalt binders, such as: for fillers for joints and cracks, for recycling agents, for insulation against water and moisture, with different requirements depending on the type of use.

Diluted asphalt is used where they want the asphalt to liquefy at a temperature lower than that normally used with the asphalt binder or without emulsifying (indicated later). Diluted asphalt is usually sprayed. They are usually prepared by dissolving asphalt in a petroleum-based solution such as e.g. petroleum, kerosene or fuel oil. Diluted asphalts are used in applications, either by spraying or by applying cold mixtures, which cause problems for human and environmental safety due to the evaporation of solvents into the atmosphere. At the time of the energy crisis of the 1970s, the use of petroleum solvents for these purposes was contrary to the default conservative criteria of the time, resulting in significantly less use of diluted asphalt even today.

Asphalt emulsions usually do not use any preparation solvents, although diluted asphalt can be used as an asphalt component (these are usually water-in-oil emulsions). This asphalt flux enters the liquid state by heating, the asphalt beads are dispersed in water and ground with a surfactant to form a stable oil-in-water emulsion. Asphalt emulsions can be of different types, such as. anionic, cationic and nonionic, depending on the surfactant used to prepare the emulsion. Emulsions are used to seal existing roads by applying a thin layer of asphalt emulsion to the surface of the road, followed by application of the aggregate to ensure that the road is insulated against water. Asphalt emulsions can be used to mix the aggregate at the site of the road foundation, or by mixing the cold mixture with the aggregate in the mixers and then paving the road with them. For emulsions, they usually use a cold mixture mixing process; however, when using a hot mix, lower temperatures are usually required compared to conventional hot mix mixing processes.

Asphalt emulsions can be used in the mixing process of hot mix for the production of asphalt concrete, and due to the inherent production difficulties, the use of an asphalt binder is more preferred. Some of these problems associated with asphalt emulsions in the hot mix process are explained below.

In a cyclic hot mixer, they accompany the discharge of water vapor released by the emulsion heating (normal content of about 30% by weight of water), an explosion where the unit is heated to a relatively high temperature, causing problems for human and environmental safety. However, in a continuous hot mixer, a short stirring time is sometimes not sufficient for adequate water release. In both production processes of mixing the hot mixture, a significant additional amount of energy is required to evaporate the water contained in the emulsion. Oil-in-water type emulsions can freeze if stored at a sufficiently low temperature, resulting in premature decay of the emulsion. If the emulsion overheats for any reason, the water may be lost too quickly and the emulsion transformed, causing serious processing problems resulting in losses in product use.

From a quality standpoint, it is paramount to remove water as quickly as possible and as completely as possible from the residual emulsion bound to the aggregate. The aqueous phase of the emulsion inevitably leads to a high water content of asphalt concrete, and the evaporation rate can be affected by the surroundings. As a result, there are uncertainties regarding both the speed and the degree of drying in the curing phase of asphalt concrete from asphalt emulsions, along with the possibility of varying significant properties at any given point in the curing process.

The asphalt emulsions used in the hot mix process include anionic emulsions, called high-liquid emulsions. The preparation of such emulsions requires a long established process in which the in-situ emulsion is stabilized by the saponification of organic acids, which are usually present as tall oil. Asphalt with improved residual properties is produced after removal of water in the hot mix process.

U.S. Pat. 2,855,319 e.g. describes an emulsion in which tallow oil is saponified with sodium hydroxide to obtain a soap of tallow oil which is used as an emulsifying agent, i.e., to obtain improved properties of the emulsion residue of hardened asphalt concrete. U.S. Pat. No. 3,904,428 similarly describes an asphalt emulsion in which e.g. Sodium hydroxide saponified oil is mixed in the presence of a significant amount of water with an asphalt binder in a specific temperature range to form a viscous gel-like mass containing more asphalt than usual. Higher asphalt content has a lesser tendency to drain it from a wet aggregate and allows a more complete coating.

U.S. Pat. No. 4,422,084 describes high-emulsion emulsion processes in which the tallow oil is first mixed with asphalt, pre-treated with various modifications that affect the properties of the asphalt, but not the decomposition of the emulsion. Also disclosed is a process in which an emulsifier containing e.g. The tallow oil, which reacted with caustic soda in aqueous solution, was mixed with asphalt. The ratio of emulsifier components can vary depending on the different compositions of the asphalt.

The publication of Tali Oil Products Division of Pulp Chemicals Associations, Tali Oil And Its Uses (F.W. Dodge Company, 1965), teaches the importance of surfactants in emulsion to replace water in the aggregate and facilitate asphalt binder bonding. To this end, the use of tallow fatty acids as emulsifying agents in liquid asphalt for road use is described.

A general overview of paving by mixing hot and cold mixtures is in Highway Engineering, Wright & Paquette, 4th ed. (John Wiley & Sons, 1979). For a more up-to-date overview of hot mix mixing processes, see Asphalt Pavements, The Asphalt Institute, Manual ser. no. 22 (MS-22), January 1983, for which reference was made earlier. For an overview of the process of mixing cold mixtures using an asphalt emulsion, see A Basic Asphalt Emulsion Manual, The Asphalt Institute, Manual ser. no. 19 (MS-19), March 1979.

The saponification reaction is used to solidify normally liquid hydrocarbons such as e.g. petrol, to facilitate safe handling and use. So e.g. U.S. Pat. No. 2,385,817 describes the hardening of normally liquid hydrocarbons by the formation of in situ metal soap obtained by saponification of a mixture of stearic acid and a resin with sodium hydroxide and a small amount of anhydrous measuring alcohol. Alcohol is supposed to accelerate the reaction. 'Liquid hydrocarbons are gasoline and other petroleum distillates that are highly flammable and are intended for use as fuels. As such, they are lighter fractions in the oil refining process than asphalt residues. Similarly, soap fats, which are otherwise based on lighter petroleum fractions, describe, e.g. Lockhart, American Lubricants (Chemical Publishing Company, 1927), p. 163 and U.S. Pat. 3,098,823. It is shown that water is an unwanted ingredient in fats. E.g. in U.S. Pat. 2,394,907 prepare fat by suspending sodium hydroxide in a non-reactive liquid medium, such as e.g. a mineral oil in which sodium hydroxide is then mixed and soaped with fatty acids without added water. By heating the mixture to the saponification temperature, they initiate a reaction that produces unwanted water as a by-product, which must then be removed.

In U.S. Pat. No. 2,888,402 describes a similar reaction using a metal hydroxide containing hydrating water that is released by heating and is thought to initiate a saponification reaction. Lithium hydroxide, considered especially as a source of water, initiates the first saping phase, followed by the second, in which they use a different metal hydroxide.

Despite the long history and widespread use of fats in which organic gels are produced by in-situ saponification, the technology of asphalt has never been used to adopt and adapt the technology of fats to achieve the essential benefits of gel formation in asphalt materials. The use of asphalt for road and roof construction, and the specific use of asphalt, remained technologically backward to the present invention for conventional asphalt binder processes and, to a lesser extent, for diluted asphalt and asphalt emulsion processes.

For the production of road pavements, the asphalt binder must be carefully selected so that asphalt concrete does not soften at higher temperatures or crack at lower ones. The need for such a choice has led to the use of softer asphalt qualities in the north and north. colder climates and harder asphalt qualities in the southern and warmer ones. In many climatic conditions, the roads are exposed to extreme high as well as low temperatures, which has led to a compromise in the selection of asphalt, without some special quality, which in its entirety corresponds to the entire climatic temperature range.

This makes the temperature sensitivity of the asphalt binder the most important when using asphalt concrete. Asphalt must remain structurally integral at high temperatures and must not become stiff and crack at low temperatures. These properties must be maintained by asphalt pavements even during many cycles of temperature change, freezing and

Ί by tilting and while constantly changing the load. The lower the slope of the viscosity / temperature curve, plotted as log-log viscosity, the more favorable are the temperature sensitivity characteristics of the asphalt binder.

Due to oxidation during prolonged exposure to the environment and traffic, asphalt binders have hardened over the years. Age hardening is the next feature of asphalt concrete that requires attention. The lower the slope of the viscosity / time curve, plotted as log-log viscosity, the more favorable the properties are due to the asphalt hardening time.

In addition, it is important that the asphalt binder used as asphalt concrete has exceptional durability when exposed to normal weather and aging. Sustainability is the quality of resistance to decay over time under given weather conditions and traffic. Repeated freezing and thawing as well as oxidation affect the aging process and are factors that affect sustainability.

It is clear that, in terms of quality, an ideal asphalt binder could be obtained by combining the characteristics of the lowest quality AC with low temperature fragility and cracking, without loss, with the high temperature properties of the more viscous higher quality AC. Unfortunately, mixing AC qualities in blending hot asphalt mixtures, even if technically feasible, inevitably results in unsatisfactory compromise properties. E.g. by mixing these qualities of asphalt, we do not preserve the desired temperature-dependent viscosity of each quality in the mixture; mixed product has viscosity properties that are somewhere between the original values.

Similarly, when considering roof asphalt binders for roof construction, considerations regarding temperature sensitivity and curing time are also considered. Multilayered asphalt roofs represent the majority of roofs from both a commercial and industrial standpoint in the US. The construction of multilayered roofs involves alternating placement of asphalt layers and asphalt-impregnated slabs on which the asphalt is applied in the hot state as a roofing binder.

Specific uses of asphalt, such as for recyclables, joints and cracks, for water and steam insulation (ASTM D449), they are also related to temperature sensitivity and cure time in determining the final product properties.

For this reason, it is, inter alia, the first purpose of the present invention to provide a gelled asphalt binder with improved properties compared to conventional asphalt binders which include reduced temperature sensitivity and a lower degree of cure time, and a second purpose to obtain good results by a conventional process of mixing hot asphalt mixture in a given hot mixer, standard rooftop and special asphalt mixer.

As stated above, the present invention provides a new multi-purpose asphalt binder. In particular, it provides an asphalt binder in a gelled state, produced by the gelation of liquefied asphalt, which is substantially free of water.

The present invention further provides a method of obtaining a gelled multipurpose asphalt binder comprising the liquefaction of substantially dry asphalt material, saponification of at least one fatty acid and at least one resin acid, by reaction with a saponifiable amount of substantially dry alkali metal base, and removal of water from the reaction to form a multi-purpose asphalt binder in a gel state.

The proposed process comprises saponification in substantially free of asphalt, at least one fatty acid and at least one resin acid, with an alkali metal base or by adding an already saponified product to the liquefied asphalt. The resulting gelled asphalt binder is used in road paving, roofing and special applications. Further features and advantages of the invention are more apparent from the description of preferred embodiments of the invention.

Typically, the asphalt binder has rheological properties of liquid at elevated temperatures used in the hot mix process. Asphalt remains a fluid capable of flowing in accordance with its special viscosity-temperature relationship between being combined with the aggregate and its application as asphalt concrete. In such a physical state, the susceptibility to runoff of an aggregate depends on factors such as temperature, nature and surface of the aggregate, and the size and configuration of the gaps.

We have now found that asphalt can be gelled by direct saponification, which requires only a very small amount (in trace amounts) of ionizing fluid to form an ionizing zone in the liquefied asphalt, in which saponification can begin. The water generated during the reaction is sufficient to sustain the reaction throughout the mixture containing asphalt and constituents formed during saponification. Water is removed as part of this process.

Due to the qualitative advantages of the gelled multi-purpose asphalt prepared according to the present invention, it is possible to select asphalt of lower quality AC (lower viscosity) to obtain asphalt concrete with low temperature properties of such quality as high-temperature asphalt of higher quality (i.e., higher viscosity). In fact, these asphalt binders allow a more flat viscosity / temperature curve than is obtained with any single quality or mixed quality. Similarly, we notice improved hardening properties and a more flat viscosity / time curve.

The term multifunctional asphalt as used herein is intended to describe a new gelled asphalt binder having reduced temperature sensitivity and improved curing time properties compared to conventional asphalt binders. The multifunctional asphalt binder is made with a new process essentially devoid of water, and its characteristics show that it can be stored at a temperature of about 104 ° C or at a higher temperature without foam. It is suitable for mixing with the aggregate to obtain asphalt concrete with the usual mixing process of hot mix, as well as for the usual roofing and for special applications.

In the process of the present invention, a gel-free multipurpose asphalt binder which is substantially free of water is obtained by gelling a liquid asphalt material substantially free of water, by saponifying at least one fatty acid and at least one resinic acid by reaction with a base. alkali metals in a finely divided, substantially dry bulk form, followed by removal of the reaction water from the resulting mixture. Water normally bound to the reaction constituents is usually sufficient to initiate the saponification reaction without causing an increase in the reaction rate to cause unwanted foaming of the reaction water as it exits the reaction mixture.

Asphalt material can be obtained from a variety of asphalt sources such as e.g. natural asphalt, rock asphalt ah preferably petroleum asphalt obtained from the oil refining process. Asphalt can be selected from those classified according to AASHTO and ASTM, but it can also be a mixture of various asphalts that are not defined by certain qualities. These include air-blown asphalt, vacuum-distilled asphalt, steam-distilled asphalt, diluted asphalt, or asphalt for roofing. Additives can be added to the asphalt, e.g. to prevent peeling, or polymers. Preferably, the AC-5 quality soft asphalt is used for multi-purpose asphalt according to the present invention, if the asphalt is to be used for road paving. Alternatively, natural or synthetic guilsonite can be selected, used alone or mixed with petroleum asphalt. Mixtures of synthetic asphalt suitable for use in the present invention are described e.g. in U.S. Pat. No. 4,437,896.

Liquid asphalt material containing saponifying ingredients is passed through a high-load colloidal mill to reduce the particle size of the alkali metal base and to disperse the base and organic acid components in the liquefied asphalt to allow the saponification reaction. The high-load mill should be of a type that reduces the particle size of the base to below 425 µm.

Alternatively, a gelled asphalt binder can be produced by adding pre-prepared soap to liquid asphalt. Since pre-prepared soap, which is essentially reaction-free water, is relatively hard, it is preferable to grind or melt it before adding it to liquid asphalt. Choosing between in situ or external saponification requires balancing some factors. Although the in situ reaction produces unwanted water in liquid asphalt, it easily evaporates at the given operating temperatures. External reaction requires special phases and accessories for reaction, storage, grinding (where the saponification product is retained as solid soap) and transport. Soap melting introduces a critical phase of temperature control and temperatures generally higher than liquid asphalt temperatures. This makes it more advantageous to carry out the in situ saponification reaction.

The asphalt material, which is preferably petroleum asphalt, is heated to obtain a free flowing liquid or to a slightly higher temperature to allow the evaporation of water resulting from the saponification reaction. It can be operated at temperatures from 177 ° C to 232 ° C, with a preferred temperature of 204 ° C.

The alkali metal base may be an alkali metal, an alkali metal oxide, an alkali metal hydroxide, or an alkali metal salt, such as e.g. metallic sodium, sodium oxide, sodium carbonate or sodium hydroxide or the corresponding potassium or lithium compounds. Preferably, the base to be added is substantially dry and in a finely divided bulk form.

The saponifiable organic acids (may also include their esters for the purposes of the present invention) may be one or more saturated or unsaturated, branched or straight chain fatty acids containing from 12 to 24 carbon atoms. Examples of such acids are: stearic, oleic, linoleic, linolenic and organosulfonic acid. The resin acids may be e.g. abietic, neo-abietinic, dihydroxyabietinic, palustrine or isodextropyme acids ah mixtures thereof.

The organic acids are preferably and advantageously added in the form of a tallow oil. Tall oil is a liquid resinous material obtained from the decomposition of wood pulp in paper production. Commercial tall oil typically comprises a complex of fatty acids, preferably acids with 18 carbon atoms, resin acids and non-absorbable components, including sterol, higher alcohols, waxes and hydrocarbons. The ratio of these constituents in tallow oil varies depending on many factors that include the geographical location of the trees used for the wood pulp. Preferably, the content of the non-attenuating substances in the tallow oil is less than 30% (ASTM D803). The ratio of fatty acid to resin should be between about 0.7 and about 2, preferably about 1: 1. As crude tall oil is used, it is preferable to use about 2% by weight of asphalt for reaction with at least a stoichiometric amount of alkali metal base. If refined tall oil or single fatty acids not derived from tall oil are selected ah, if the fatty acids are mixed with resin acids in synthetic tall oil, then they must roughly correspond to the acid components of the crude tall oil. In general, complete neutralization of the alkali metal base with the tallow oil is preferred, indicating an approximately equimolar amount of acid and base.

The initiation of the saponification reaction requires the presence of an extremely small amount of ionizing medium, such as e.g. water. Normally present water, such as moisture on the surface of a hygroscopic base, such as a substantially dry sodium reactant, is usually sufficient. Similarly, water normally present in commercial crude oil is more than adequate to initiate the reaction. However, if a base is selected which has one or more hydration water molecules attached, such as e.g. hydrated lithium hydroxide, then the heat of the liquid asphalt releases enough water to initiate the reaction.

If the entire reaction system contains neither water nor any other ionizing medium (eg when using a dry non-hygroscopic base and refined tallow oil without water), the addition of a small amount of water to the liquid asphalt initiates the reaction. However, it is important to add it to the moment it is installed in the liquid asphalt before it evaporates. Therefore, it is usually sufficient to inject it into or near the mill inlet. We found that approximately satisfactory water content was less than 0.001% by weight. In practice, the saponification reaction takes place with quantities of water that are not measurable by standard techniques.

Regardless of the origin of the ionizing medium, the good mixing achieved during the grinding phase is usually sufficient for the desired distribution before evaporation occurs. If reaction water is formed and an excess of ionizing medium is present, then evaporation is desired to obtain a substantially dry asphalt binder.

Smaller amounts of alcohol, such as methyl alcohol or other lower aliphatic alcohols, can similarly be used as ionizing agents. An alcoholate formed by the reaction with an alkali metal hydroxide enables the saponification reaction to be produced in the same way, resulting from the formation of water during the reaction. U.S. Pat. No. 2,385,817 describes alcohols for accelerating the saponification of liquid hydrocarbons such as gasoline. In general, the use of alcohols should be avoided because of the additional complexity of the process, since it is necessary to store and manipulate another ingredient.

The following examples illustrate the present invention:

EXAMPLE 1

1500 g of AC-20 asphalt binder, preheated to 232 ° C, are placed in a heated and insulated conical bottom vessel with a volume of 3.85 1. The bottom of the cone is fitted with a valve to allow the asphalt to pass through the colloid mill and return to the top of the container. While the asphalt is circulating through the mill, 3.7 g of sodium hydroxide is added to the grain. Grains are protected from moisture to avoid unwanted water. Continue circulating the mixture for about 2 minutes and then pass the samples through a mesh 40 (425 μ, πι) sieve. 30 g of crude tallow oil were added to the circulating mixture. The following reaction produces 1 mole of water for each mole of organic acid in crude tall oil, leaving the water as a foam under continuous heating and stirring. As the reaction proceeds, the viscosity of the mixture increases. Stirring was continued until foaming had ceased, indicating that the reaction was complete within about 15 minutes after the addition of the tallow oil. We take samples to test.

The results of the various tests are listed in Table 1 and Figures 1-3, together with the results obtained for the asphalt binder samples, before being subjected to multifunctional treatment according to the above procedure.

EXAMPLE 2

We operate according to the procedure of Example 1, using the AC-5 asphalt binder instead of the AC-20 of Example 1. The physical properties of the resulting asphalt binder are listed in Table 1 and Figures 1-3 compared to the properties obtained by testing the same asphalt binder , before being exposed to the multifunctional treatment of Example 1.

EXAMPLE 3

We operate according to the procedure of Example 1, using the AC-10 asphalt binder instead of the AC-20 of Example 1. The physical properties of the resulting asphalt binder are listed in Table 1 and Figures 1-3 compared to the properties obtained by testing the same asphalt binder , before being exposed to the multifunctional treatment of Example 1.

Multifunctional gelled asphalts are described in Table 1 and Figures 1-3, both in terms of normal asphalt quality and equivalent quality, expressed by a viscosity at 60 ° C, into which these qualities are converted by multifunctional treatment. E.g. MG-5-20 stands for multi-purpose asphalt made of AC-5 asphalt, having a viscosity of AC-20 at 60 ° C.

TABLE 1

Before processing After multi-purpose processing

AC-40 AC-20 AC-10 AC-5 AC-20 AC-10 AC-5 Penetration at 4'C, 200 g, 60 s, dmm 16 21 31 47 21 31 53 Penetration at 25'C, dmm 44 72 111 172 52 84 131 Viscosity at 4'C, 0.1 s -1, Pa.sxl0 ⁶ 16.0 6.2 2.2 1.5 8.0 5.4 3.0 Viscosity at 60'C, 1 s -1, Pa.s 350,0 182,0 91,0 53,0 395,0 298,0 220,0 Viscosity at 135'C, 10 s -1, Pa.szlO ' ¹ 4.7 3.7 2.50 2.20 19 14 6.50 The softening point 'C 57 51 47.5 44 74 67.6 66 Penetration index (PD +0.1 +0.3 +0.4 +0.1 +3,5 +5.8 +5.4 Pen Viscosity Number (PVN) -0,89 -0.68 -0,84 -0.47 +1.29 +1.58 +1.09 Viscosity after 5 h TFOT 640.0 380.0 175.0 115.0 630,0 420,0 240,0 Aging index 1.83 2.08 1.93 2.17 1.59 1.41 1.09

Viscosity after 15 h TFOT 2640,0 1670,0 677.0 390.0 120,0 480,0 330,0 Aging index 7.43 9:18 7.44 7.34 3.30 1,40 1.50

Viscosity after TFOT rolling

Aging index

890,0

2.54

439.0 210.0 111.0 530.0 431.0 380.0

2.41 2.31 2.09 1.34 1.45 1.73

The results shown in Table 1 allow a direct comparison of the different properties of these types of asphalt binders before multifunctional treatment (which is a typical hot mix of asphalt binders) and after. The tests involve two procedures, which are widely used to determine the temperature sensitivity of asphalt.

The first procedure is the penetration index (Pl) developed by Pfeiffer & VanDoormal, cited in Journal of the Institute of Petroleum Technologists 12; 414 (1936). In this procedure, the value 0 is assumed for typical road bitumen. Values greater than 0 are less temperature sensitive and values less than 0 are more temperature sensitive asphalt binders. Table 1 shows that Pl essentially improves with multifunctional treatment on all asphalt qualities tested.

The second procedure is the Pen-Viscosity (PVN) number developed by McLeod, cited in Proceedings of Asphalt Paving Technologists 41: 424 (1972). PVN uses high temperature viscosity of asphalt as well as penetration compared to the PVN indices of good and bad asphalt. Values greater than 0 indicate asphalt less sensitive to temperature than less than 0. Table 1 shows that all tested asphalts are similarly improved in terms of temperature sensitivity by multi-purpose treatment.

Figure 1 shows the relationship between penetration, which is a measure of viscosity, and temperature. Multi-purpose asphalts give a more gentle curve, resulting in lower temperature sensitivity.

Similarly, Figure 2 shows a graphical representation of a milder slope of the viscosity / temperature curve for asphalt improved with a multi-purpose process. All multi-purpose treated asphalts have a gentler slope of the curve, resulting in lower temperature sensitivity than conventional untreated asphalts.

Table 1 also shows the effects of the process of the present invention on asphalt hardening with aging. ASTM D1754 Test Method for Effect of Healt and Air on Asphaltic was used to indicate the speed of curing of asphalt with aging

Materials (TFOT). The aging rate obtained by dividing the viscosity of the asphalt after TFOT by the viscosity before TFOT is also shown. This viscosity ratio after the heat treatment of the thin layer compared to the viscosity before it is called the aging index. Table 1 shows the significant improvement in asphalt after multi-purpose treatment in terms of both TFOT and aging index.

The thin-layer heat treatment test was extended to show the long-lasting effect of thin-layer asphalt aging on increasing the aging time from 5 hours to 15. Table 1 shows that the aging speed of the asphalt is significantly reduced by the treatment described in the examples.

Figure 3 shows a diagram of the viscosity change as a function of aging time with aging by testing the heat treatment of the thin layer. It is evident that multi-purpose asphalts produce milder slopes of the viscosity / TFOT curves, which results in a slower aging rate than for conventional asphalts.

It should be emphasized that normal procedures for measuring the viscosity of asphalt binders, such as e.g. ASTM D2170 and ASTM D2171 are not usable for multi-purpose asphalt because asphalt is not non-Newtonian in nature. Due to non-Newtonian properties, the following are preferred: ASTM P-160 (1984) Viscocity of Asphalt Emulsion Residues and Non-Newtonian Bitumens using a Vacuum Capillary Viscometer. The results of the various tests are shown in Table 1 together with the results obtained with the asphalt samples before being subjected to multifunctional treatment according to the procedures described above.

Prior priming tests show that multifunctional treatment significantly and preferably affects the penetration, viscosity and viscosity quality after TFOT aging after 5 and 15 hours. Thus, e.g. viscosity of AC-5 asphalt before treatment of 53 Pa.s at 60 ° C. Multipurpose treatment of this asphalt results in an increase in viscosity to 220 Pa.s, which meets the viscosity requirements of AASHTO M-226 for AC-20 asphalt. Similarly, the aging properties of all asphalt paving have been significantly improved by multi-purpose machining.

EXAMPLE 4

We operate according to the procedure of Example 1, using 1500 g of AC-10 instead of the asphalt binder of Example 1 and 5.25 g of anhydrous potassium hydroxide instead of the sodium hydroxide of Example 1. The test results are shown in Table 2.

EXAMPLE 5

We operate according to the procedure of Example 4, using 2.24 g of anhydrous lithium hydroxide instead of potassium hydroxide of Example 4. The test results are shown in Table 2.

EXAMPLE 6

We operate according to the procedure of Example 4, using 4.5 g of anhydrous sodium carbonate instead of potassium hydroxide of Example 4. The test results are shown in Table 2.

TABLE 2

Example 4 KOH Example 5 LiOH Example 6 At ₂ CO ₃ AC-10 Control Penetration, dmm 75 87 70 90 Viscosity at 60 ° C, Pa.s 185,0 134.0 230,0 115,0 Softening point, ° C 53.5 52,5 65 50 Penetration Index (PI) +0.8 +0.6 +2,9 +0.2 Viscosity by (TFOT) 5 h, Pa.s 274,3 286,0 418,9 305,0 Aging index 1.49 2.13 1.82 2.65 Viscosity by (TFOT) 15 h, Pa.s 560,0 817,4 641,7 1140,0 Aging index 3.03 6,1 2.79 9.91

Table 2 shows that all asphalt binders are substantially improved in terms of temperature sensitivity based on penetration index and long-term aging index compared to the control AC-10 used as base asphalt.

EXAMPLE 7

We operate according to the procedure of Example 4, using 2.2 g of metallic sodium instead of the potassium hydroxide of Example 4. Less foam is observed. The results of the experiment are shown in Table 3.

EXAMPLE 8

We work according to the procedure of Example 4, whereby the crude tallow oil is first added to the asphalt binder, followed by mixing with the addition of potassium hydroxide grains in the colloidal mill. The results of the experiment are shown in Table 3.

This example shows that the reverse order of chemical addition does not have a significant effect on the properties of multi-purpose treated asphalt.

EXAMPLE 9

In the vessel of Example 1, 500 g of crude tallow oil heated to 149 ° C was then stirred thoroughly, followed by 62.5 g of sodium hydroxide. 33.75 g is removed from the resulting mixture and 1500 g of AC-10 asphalt maintained at 204 ° C is added to it. The resulting mixture is passed through a colloidal mill. The multifunctional product is tested as previously stated and the results are shown in Table 3.

TABLE 3

Example 7 Metal sodium Example 8 Talovo ol is- first Example 9 Talovo oil and caustic soda added together Control AC-10 Penetration, dmm 68 67 72 90 Viscosity at 60'C, Pa.s 310,5 327,5 240,0 115,0 Softening point, ° C 71 66 63 50 Penetration Index (PI) +3,8 +2,9 +2,5 +0.2 Viscosity (ATFOT), 5 h, 365,0 590,0 562,0 305,0 Aging index 1.82 1.80 2,34 2.65 Viscosity (ATFOT), 15 h 480,5 827,5 812,5 1140,0 Aging index 2.71 2,53 3,39 9.91

The above results show the physical properties obtained with the multi-purpose asphalt products of Examples 7-9. The results show a significant improvement in temperature sensitivity and maturation with the aging of the multifunctional asphalt binder, when compared with the control AC-10, regardless of the order of addition of ses20 mats.

EXAMPLE 10

The tests are performed to show the sensitivity of asphalt emulsion residues containing high-liquid residues with respect to the moisture remaining in the mixture. The washed limestone ASTM no. 8 is coated with 4% by weight multifunctional asphalt binder made of AC-5 asphalt (yielding MG5-20 asphalt binder) and compared with similarly prepared conventional AC-20 asphalt (ASSHTO M-226). The HFMS-2h asphalt emulsion (ASSHTO M-140) is also mixed with the aggregate by adding 5.7% by weight of the emulsion to produce 4% by weight of the residual asphalt mixture. Each batch of asphalt binder is mixed for 90 seconds with the aggregate at 149 ° C. The unit is heated approximately 38 ° C more with HFMS-2h asphalt emulsion to remove water. The final temperature of the mixture in all cases is 135 ° C.

Approximately 300 g of each mixture was placed in an oven at 149 ° C on a sieve no. 4 with a diameter of 20,32 cm. Put a container under each sieve to intercept the sifted asphalt. The results are as follows:

MG 5-20 AC-20 HFMS-2h

Grams of asphalt in a container 0 9,9 1,3

These tests illustrate the resistance of multifunctional asphalt to migration from the aggregate compared to the conventional AC-20 asphalt binder and high-strength medium-hardened asphalt emulsion residue. A special feature of high-liquid residues is that they allow the lower migration of asphalt in hot mixes. These tests show that this is true of the AC-20; multi-purpose asphalt, however, is decidedly superior in that compared to HFMS emulsion residues.

EXAMPLE 11

The properties of the mixture of Example 10 were measured over a wide temperature range. The purpose of these tests is to determine if improvements to multi-purpose asphalt binders could also improve the properties of asphalt aggregates (primary end use of the material).

The same asphalt as used in the study of drainage from Example 10 is used in the asphalt aggregate mixture to be studied in this case. ASTM unit no. 5, aggregate no. 8 and fine sand are mixed to form a 19 mm (3/4 ”) compact mixture (ASTM D-3515). The aggregate and asphalt were heated to 149 ° C before mixing, with HFMS-2h mixed with the aggregate at 204 ° C and HFMS-2h at 25 ° C for 90 seconds. Each combined mixture has 4.5% by weight of asphalt. Combine each mixture with 75 strokes according to Marshall compaction and according to ASTM D-1559. Four mixtures are made with each asphalt and tested at four temperatures: 60 ° C, 38 ° C, 25 ° C and 4.5 ° C. This temperature range represents a wide range of temperatures that are actually relevant for paving. The hardness is measured on the Marshall and Hveem apparatus in accordance with ASTM D-1559 and ASTM D-1560. The results are shown in Table 4.

TABLE 4

Test / temp. 'C MG 5-20 AC-20 HFMS-2h emulsion Hveem 60 56 55 20 38 55 63 27 25 55 66 33 4.5 79 87 56 Marshall 60 2450 2550 900 38 2850 4150 1250 25 3100 4750 1850 4.5 10000 17500 2900

These results show that the hardness (i.e., stability) of asphalt concrete made from multi-purpose asphalt binder did not increase as much as from conventional asphalt binder.

The results also show that the emulsion mixture (HFMS-2h) has too little stability at high temperatures, which can be attributed to incomplete binding (i.e., the presence of residual moisture).

In Examples 12-14, tests were performed to show the small amount of water required to initiate the saponification reaction in a process for making a multipurpose asphalt binder.

EXAMPLE 12

Heat 1500 grams of AC-10 asphalt to 204 ° C and place in the same container as used in Example 1. Sodium hydroxide 3.75 g was pre-warmed to dryness, melted and added to the asphalt and stirred for 1 minute. The tall oil was heated at 135 ° C for 2 hours to dry completely. 30 g of dried tallow oil was added to the mixture of asphalt and caustic soda and milled for 15 minutes. The test results are listed in Table 5.

EXAMPLE 13

We operate according to the procedure of Example 12, except that 2.2 g of metallic sodium is used instead of sodium hydroxide. The test results are shown in Table 5.

EXAMPLE 14

Work according to the procedure of Example 13 and add 0.015 g of water to the tallow oil and stir before adding to the asphalt.

TABLE 5

Penetration at 4'C, 200 g, 60 s, dmm

Penetration at 25'C, 100 g, 5 s, dmm

Viscosity at 60'C, s ¹ , Pa.s

The softening point, 'C

Example 12 (dry)

Example 13 (dry)

111

Example 14 (water)

Penetration Index (Pl)

Viscosity after 5 h (TFOT), Pa.s

Aging index

Viscosity after 15 h (TFOT), Pa.s

Aging index

307.5 +4,3

425,00

1.38

497.5

1.62

920,0

47.5 +0.7

178,5

1.92

682,0

7.41

275,0 +3,8

401,0

1.45

679,5

2.47

The results show that the saponification reactions occurring in Examples 12 and 14 give comparable properties to the asphalt binder. In the reaction in Example 12, these reactants were particularly dry. Nevertheless, there was sufficient moisture (under laboratory measurement) in the system to initiate the reaction.

In Example 13, no reaction occurred, although the same procedure was used to dry the tallow oil. Here, metal sodium was used in place of the dry molten sodium hydroxide of Example 12.

However, using metal sodium and metallic tallow oil and adding a small amount of water (0.001% by weight of asphalt) to the mixture, the saponification reaction was carried out as shown in Example 14.

EXAMPLE 15

We use the procedure described in Example 1 to use Type I Roofing Asphalt (ASTM D312) instead of AC-12. Table 6 shows the results of the test compared to the base asphalt, with reference to typical roof covering tests.

TABLE 6

Before processing TYPE I Po processing (MG-TYPE-I-II) TYPE I ASTM D312 TYPE II DESCRIPTION Softening pointCa 'C 63 78 75.5 to 80 Penetration at 0'C, 200 g, 60 s, dmm 14 14 6+ Penetration at 25'C, 100 g, 5 s, dmm 40 34 18 to 40 Penetration at 46'C, 50 g, 5 s, dmm 102 70 100 Penetration Index, Pl -2,2 0

The tests show that treated asphalt has low-temperature asphalt properties for type I roofs and high-temperature asphalt properties for type II roofs. Pl is also substantially lower in treated asphalt, which results in a lower temperature sensitivity.

Claims (13)

A gelled asphalt binder, characterized in that it is made by gelling liquid asphalt substantially free of water. Geled asphalt binder according to claim 1, characterized in that it is made by the addition of tallow oil and at least a sufficient amount of saponification of substantially dry alkali metal hydroxide to a substantially water-free liquid asphalt. Geled asphalt binder according to claim 2, characterized in that the tallow oil contains fatty acids and resin acids in a ratio of from about 0.7 to about 2, preferably in a ratio of about 1: 1. 4. A process for making a gelled multi-purpose asphalt binder, comprising: a) liquefaction of asphalt material that is substantially dry b) saponifying therein at least one fatty acid and at least one resinic acid by reaction with at least a saponification of substantially dry alkali metal base for saponification, and c) removal of the reaction water to form a gelled multipurpose asphalt binder. 5. The method of claim 4, wherein the asphalt material is petroleum asphalt. Method according to claim 4 or 5, characterized in that the asphalt material is AC-1, AC-2, AC-5, AC-10, AC-20, AC-30, AC-40, AC-50 or a mixture or asphalt for type I, II or III roofs or a mixture thereof. Process according to claims 4,5 or 6, characterized in that the fatty acids and resin acids are added as tallow oil. Process according to claims 4, 5, 6 or 7, characterized in that the alkali metal base is an alkali metal hydroxide, preferably sodium hydroxide. 9. A process according to claim 5, characterized in that the petroleum asphalt is heated to the liquor and Ie to be added an alkali metal hydroxide, which is substantially dry and in a finely divided, bulk form, the resulting mixture is then milled in a colloidal mill, reduce the particle size of the alkali metal bulk hydroxide and to disperse said bulk material in petroleum asphalt and then, during mixing, add a quantity of tallow oil sufficient for saponification to produce a gelled multi-purpose asphalt binder, the reaction system containing a small but sufficient amount of water, to initiate a saponification reaction without causing foaming and removal of water. 10. A process according to claim 5, characterized in that the tallow oil and alkali metal hydroxide are pre-mixed and added to the petroleum asphalt. A process according to claims 7, 8, 9 or 10, characterized in that the tallow oil contains fatty acids and resin acids in a ratio of about 0.7 to about 2, preferably in a ratio of about 1: 1. A paving process comprising mixing a gelled asphalt binder according to any one of the preceding claims with a substantially water-free aggregate, distributing the gel aggregate mixture to the surface to be paved, and compacting the distributed mixture to the desired density, to make a layer of asphalt concrete. 13. A method for asphalt paving, characterized in that it comprises applying and rolling to the surface of the roof asphalt impregnated felt, by absorbing at least one layer of multipurpose asphalt binder according to any one of claims 1 to 11, to produce an asphalt roof.