DE102022107696A1 - Modified asphalt and process for its production - Google Patents

Abstract

The invention relates to the field of asphalt technology, in particular modified asphalt and a process for its production. The modified asphalt includes the following raw material components by weight: 70 ~ 90 parts of base asphalt and 10 ~ 18 parts of modifier; the modifier is a mixture of SBS, calcium oxide and n-butyl acrylate.

Description

FIELD OF TECHNOLOGY

The invention relates to the field of asphalt technology, in particular modified asphalt and a process for its production.

BACKGROUND

In the last decade, highway construction in China has developed rapidly. Since the founding of the People's Republic of China, the number of kilometers of roads has grown from tens of thousands of kilometers to the largest road network in the world. Compared with cement pavement, asphalt pavement has the advantage of higher driving comfort, stable and low noise, easier maintenance, etc. Asphalt is the first choice in highway construction in various countries. A highway has the characteristics that a high volume of traffic flows over it, it is driven at high speeds and a high load is applied to it, so there are higher requirements for the surface: good durability, high load-bearing capacity, smooth surface and good slip resistance. In recent years, China's economy has developed rapidly, the number of privately owned vehicles has increased rapidly, and traffic on expressways is increasing year by year, bringing new challenges to road use at all levels, especially the ever stricter requirements for the performance of the asphalt pavement on well-developed highways.

SBS modified asphalt means that a certain amount of SBS modifier is added to the base asphalt. At a certain temperature, the SBS modifier can be evenly distributed in the base asphalt through special manufacturing processes such as shearing and stirring to achieve a mixing state and improve the performance of the asphalt using the physical structure of SBS in the asphalt. Rubber powder modified asphalt refers to adding a certain amount of fine rubber powder produced by special processing technology to the asphalt from old tires, processing and treatment through mechanical operations such as shearing and mixing at high temperature, and finally an asphalt rubber powder binder with improved swelling properties and is generated in other stages. Currently, SBS-modified asphalt is widely used in road construction in China and is widely accepted by engineers and technical personnel. Asphalt modified with rubber powder is gradually becoming established as a new type of modified asphalt. It is a type of asphalt with great development potential and plenty of room for further development.

Ordinary SBS asphalt has some performance disadvantages, such as poor adhesion, low elongation, high wax content and high temperature sensitivity. It is therefore difficult to use on well-developed expressways; At the same time, due to the rapidly growing traffic volume caused by economic growth, the significantly increasing load from vehicles and the high temperature differences between north and south, winter and summer in China, higher requirements apply to the quality of the asphalt pavement.

It is against this background that the present invention is presented.

DEMOLITION

• 70 ~ 90 Teile von Grundasphalt und 10 ~ 18 Teile eines Modifikators;
• der Modifikator ist eine Mischung aus SBS, Calciumoxid und n-Butylacrylat.
• Alternativ umfasst, gemäß dem vorstehend beschriebenen modifizierten Asphalt, der Modifikator 6 ~ 9 Gewichtsteile von SBS, 3 ~ 6 Gewichtsteile von Calciumoxid und 1 ~ 3 Gewichtsteile von n-Butylacrylat.
• Alternativ umfasst, gemäß dem vorstehend beschriebenen modifizierten Asphalt, der Modifikator 7 ~ 8 Gewichtsteile von SBS, 4 ~ 5 Gewichtsteile von Calciumoxid und 2 Gewichtsteile von n-Butylacrylat.
• Alternativ ist, gemäß dem vorstehend beschriebenen modifizierten Asphalt, der Grundasphalt ein Asphalt Nr. 90 Klasse A.
• Alternativ enthält er, gemäß dem vorstehend beschriebenen modifizierten Asphalt, zumindest eins von einem Emulgator, Vernetzer, Verträglichkeitsvermittler und Stabilisator.
• Alternativ ist, gemäß dem vorstehend beschriebenen modifizierten Asphalt, der Emulgator 1 ~ 5 Gewichtsteile oder 2, 3, 4 Gewichtsteile von JY-R2-Emulgator.
• Alternativ ist, gemäß dem vorstehend beschriebenen modifizierten Asphalt, der Vernetzer 1 ~ 3 Gewichtsteile oder 2 Gewichtsteile von kristallinem Schwefel.
• Alternativ ist, gemäß dem vorstehend beschriebenen modifizierten Asphalt, der Verträglichkeitsvermittler 1 ~ 3 Gewichtsteile oder 2 Gewichtsteile von naphthenhaltigem Öl.
• Alternativ ist, gemäß dem vorstehend beschriebenen modifizierten Asphalt, der Stabilisator 5 ~ 10 Gewichtsteile oder 6, 7, 8, 9 Gewichtsteile von Asbestasche.

The invention relates to a modified asphalt which comprises the following raw material components by weight:

• 70 ~ 90 parts of base asphalt and 10 ~ 18 parts of a modifier;
• the modifier is a mixture of SBS, calcium oxide and n-butyl acrylate.
• Alternatively, according to the modified asphalt described above, the modifier includes 6 ~ 9 parts by weight of SBS, 3 ~ 6 parts by weight of calcium oxide and 1 ~ 3 parts by weight of n-butyl acrylate.
• Alternatively, according to the modified asphalt described above, the modifier includes 7 ~ 8 parts by weight of SBS, 4 ~ 5 parts by weight of calcium oxide and 2 parts by weight of n-butyl acrylate.
• Alternatively, according to the modified asphalt described above, the base asphalt is No. 90 Class A asphalt.
• Alternatively, according to the modified asphalt described above, it contains at least one of an emulsifier, crosslinker, compatibilizer and stabilizer.
• Alternatively, according to the modified asphalt described above, the emulsifier is 1 ~ 5 parts by weight or 2, 3, 4 parts by weight of JY-R2 emulsifier.
• Alternatively, according to the modified asphalt described above, the crosslinker is 1 ~ 3 parts by weight or 2 parts by weight of crystalline sulfur.
• Alternatively, according to the modified asphalt described above, the compatibilizer is 1 ~ 3 parts by weight or 2 parts by weight of naphthenic oil.
• Alternatively, according to the modified asphalt described above, the stabilizer is 5 ~ 10 parts by weight or 6, 7, 8, 9 parts by weight of asbestos ash.

• Erhitzen und Mahlen von Komponenten, die kein Grundasphalt sind, um eine Mischung zu erhalten;
• Langsames Hinzufügen der Mischung zum Grundasphalt, der zum Schmelzen und gleichmäßigen Rühren erhitzt ist, und dann natürliches Abkühlen nach Scherwirkung durch den Emulgator.
• Alternativ, gemäß dem vorstehend beschriebenen Verfahren der Herstellung, beträgt die Scherdrehzahl 17000 U/min ~ 20000 U/min und die Scherzeit 20 min ~ 40 min.
• Vorteilhafte Wirkungen: Die Erfindung nutzt einen gemischten Modifikator, der SBS, Calciumoxid und n-Butylacrylat zur Modifizierung enthält, wobei n-Butylacrylat mit SBS und Calciumoxid zusammenwirken kann, um die Gesamtstärke des Asphalts zu erhöhen, und der Zusatz von Calciumoxid und n-Butylacrylat auch erheblich die Wetterfestigkeit von Asphalt steigern kann. Nach Optimierung der Verträglichkeit der Rohstoffe ist die Herstellung einfach und es ist nicht notwendig, Modifikatoren, Stabilisatoren und andere Komponenten mehrfach hinzuzufügen.

A further aspect of the invention relates to a method of producing modified asphalt as described above, comprising:

• Heating and grinding components other than base asphalt to obtain a mixture;
• Slowly adding the mixture to the base asphalt heated to melt and evenly stir, then allowing it to cool naturally after shearing from the emulsifier.
• Alternatively, according to the manufacturing method described above, the shearing speed is 17000 rpm ~ 20000 rpm and the shearing time is 20 min ~ 40 min.
• Beneficial effects: The invention uses a mixed modifier containing SBS, calcium oxide and n-butyl acrylate for modification, where n-butyl acrylate can cooperate with SBS and calcium oxide to increase the overall strength of asphalt, and the addition of calcium oxide and n-butyl acrylate can also significantly increase the weather resistance of asphalt. After optimizing the compatibility of raw materials, production is easy and there is no need to add modifiers, stabilizers and other components multiple times.

DETAILED DESCRIPTION

The embodiment of the invention will be described in detail below in connection with the embodiment. It is to be understood that these embodiments are intended only to illustrate the invention and not to limit the scope of the invention. For the experimental procedures without specific conditions specified in the following embodiments, priority should be given to the specifications specified in the invention, according to the experimental manual or the conventional conditions known in the art, or according to the conditions specified in the Manufacturer recommends.

In the following specific embodiments, the measurement parameters associated with raw material components may have slight variations within the weight accuracy ranges unless otherwise specified. Taking into account the parameters of temperature and time, an acceptable deviation is allowed due to instrument-based test accuracy or operational accuracy.

example 1

• 1) Swelling: heating 70 kg of No. 90 Class A base asphalt to melt the base asphalt;
• 2) Heating 6kg SBS, 3kg calcium oxide, 3kg n-butyl acrylate, 1kg JY-R2 emulsifier, 3kg crystalline sulfur, 1kg naphthenic oil and 10kg asbestos ash to 140°C ~ 160°C (mainly conducive to mixing n-butyl acrylate), grinding and mixing to obtain the mixture;
• 3) Add the above mixture to the melted asphalt in several portions while stirring. Make sure that no bubbles form when mixing and add additional defoamer if necessary.
• 4) In the molten state (about 180°C ~ 210°C), a single-stage high gravity emulsifying machine is used for high-speed shearing and stirring. The shearing speed is 17000 rpm and the shearing time is 40 min;
• 5) Natural cooling.

Example 2

• 1) Swelling: heating 90 kg of No. 90 Class A base asphalt to melt the base asphalt;
• 2) Heating 9kg SBS, 6kg calcium oxide, 1kg n-butyl acrylate, 5kg JY-R2 emulsifier, 1kg crystalline sulfur, 3kg naphthenic oil and 5kg asbestos ash to 140°C ~ 160°C (mainly conducive to mixing n-butyl acrylate), grinding and mixing to obtain the mixture;
• 3) Add the above mixture to the melted asphalt in several portions while stirring. Make sure that no bubbles form when mixing and add additional defoamer if necessary.
• 4) In the molten state (about 180°C ~ 210°C), a single-stage high gravity emulsifying machine is used for high-speed shearing and stirring. The shearing speed is 20,000 rpm and the shearing time is 20 min;
• 5) Natural cooling.

Example 3

• 1) Swelling: heating 80 kg of No. 90 Class A base asphalt to melt the base asphalt;
• 2) Heating 7 kg SBS, 5 kg calcium oxide, 2 kg n-butyl acrylate, 3 kg JY-R2 emulsifier, 2 kg crystalline sulfur, 2 kg naphthenic oil and 7 kg asbestos ash to 150 ° C (mainly conducive to mixing of n-butyl acrylate), grinding and mixing to obtain the mixture;
• 3) Add the above mixture to the melted asphalt in several portions while stirring. Make sure that no bubbles form when mixing and add additional defoamer if necessary.
• 4) In the molten state (about 180°C ~ 210°C), a single-stage high gravity emulsifying machine is adopted for high-speed shearing and stirring. The shearing speed is 20,000 rpm and the shearing time is 20 min;
• 5) Natural cooling.

Comparative example 1.

Based on Example 3, n-butyl acrylate was replaced with an equal amount of calcium oxide.

Comparative example 2.

Based on Example 3, calcium oxide was replaced with an equal amount of n-butyl acrylate.

Comparative example 3.

Based on Example 3, calcium oxide and n-butyl acrylate were replaced with an equal amount of SBS.

Experimental example

Basic indexes of modified asphalt (test carried out according to standard JTG F40-2004 and test method JTJ052-2000): Table 1 Base indices group Tested Test value default value Example 3 Needle penetration 67 IC: 60-80 25°C (10-1 mm:100 g) 5 s ID: 30-60 Ductility 33 IC: ≥30 5°C, 5 cm/min (cm) ID: ≥20 softening point 68 IC: ≥55 T&B °C ID: ≥60 Comparative example 1 Needle penetration 63 IC: 60-80 25°C (10-1 mm:100 g) 5 s ID: 30-60 Ductility 26 IC: ≥30 5°C, 5 cm/min (cm) ID: ≥20 softening point 67 IC: ≥55 T&B °C ID: ≥60 Comparative example 2 Needle penetration 67 IC: 60-80 25°C (10-1 mm:100 g) 5 s ID: 30-60 Ductility 32 IC: ≥30 5°C, 5 cm/min (cm) ID: ≥20 softening point 63 IC: ≥55 T&B °C ID: ≥60 Comparative example 3 Needle penetration 61 IC: 60-80 25°C (10-1 mm:100 g) 5 s ID: 30-60 Ductility 24 IC: ≥30 5°C, 5 cm/min (cm) ID: ≥20 softening point 65 IC: ≥55 T&B °C ID: ≥60

It is seen that the modified asphalt produced by the invention meets the national standard and achieves good performance. Removing n-butyl acrylate obviously affects the ductility of asphalt.

The results of the low-temperature bending test are included in Table 2, and the size of the test piece is 40 mm × 40 mm × 200 mm. Table 2 Results of the low temperature bending test Example no. Cross section height (mm) Test body span (mm) Deflection in the middle (µm) Average failure due to stress (µg) Example 3 40.0 200 603.6 3321.6 Comparative example 1 459.4 2531.1 Comparative example 2 479.9 2757.2 Comparative example 3 448.7 2489.7

The low-temperature properties of asphalt are important factors affecting low-temperature fracture behavior. The low-temperature bending test shows that both n-butyl acrylate and calcium oxide can significantly influence the low-temperature properties of asphalt.

Evaluation of stability at high temperatures

Rut test: The size of the rut plate is 300mm × 300mm × 100mm, the test temperature is 60 □. The deformation at 45 min and 60 min is considered and the number of revolutions of the test wheel at 1 mm deformation is calculated as the dynamic stability. The results are shown in Table 3. Table 3 Results of the rutting test Example no. Rut depth (mm) at the following time (min) Average value of dynamic stability (number/mm) Technical requirement (number/mm) 45 60 Example 3 0.839 1,214 6715 Comparative example 1 2,985 3,453 4110 Comparative example 2 2,537 2,698 5316 Comparative example 3 3,036 3,513 4081

The stability after rutting of the modified asphalt provided by the invention is higher than that required by the current specification. Compared with the example, the performance of comparative examples 1 ~ 3 is significantly lower.

In combination with the above experimental results, it is shown that the modified asphalt provided by the invention has good weather resistance.

The above embodiments only represent various embodiments of the invention and the description is more specific and detailed, but it is to be understood that the scope of the invention is not limited thereby. It should be apparent to those skilled in the art that various modifications and improvements are possible without departing from the concept of the invention, which remain within the scope of the invention. Therefore, the scope of the patent is determined by the claims below, and the specifications and accompanying drawings may be used to explain the content of the claims.

Claims (10)

Modified asphalt, comprising the following raw material components by weight: 70 ~ 90 parts of base asphalt and 10 ~ 18 parts of a modifier; where the modifier is a mixture of SBS, calcium oxide and n-butyl acrylate. Modified asphalt after Claim 1 , wherein the modifier comprises 6 ~ 9 parts by weight of SBS, 3 ~ 6 parts by weight of calcium oxide and 1 ~ 3 parts by weight of n-butyl acrylate. Modified asphalt after Claim 1 , where the base asphalt is asphalt No. 90 Class A. Modified asphalt according to one of the Claims 1 - 3 , which contains at least one of an emulsifier, crosslinker, compatibilizer and stabilizer. Modified asphalt after Claim 4 , where the emulsifier is 1 ~ 5 parts by weight of the emulsifier JY-R2. Modified asphalt after Claim 4 , where the crosslinker is 1 ~ 3 parts by weight of crystalline sulfur. Modified asphalt after Claim 4 , where the compatibilizer is 1 ~ 3 parts by weight of naphthenic oil. Modified asphalt after Claim 4 , where the stabilizer is 5 ~ 10 parts by weight of asbestos ash. Process for producing modified asphalt according to one of Claims 1 - 8th , comprising: heating and grinding components other than base asphalt to obtain a mixture; and Slowly adding the mixture to the base asphalt heated to melt and evenly stir, and then allowing it to cool naturally after shearing by the emulsifier. Modified asphalt after Claim 9 , where the shearing speed is 17000 rpm ~ 20000 rpm and the shearing time is 20 min ~ 40 min.