Asphalt cast type 2 hard specifications. Cast asphalt and features of its application. Source Requirements

A few centuries ago, the most modern road surface was paving stones. However, talking about the smooth ride on such a coating, of course, was not necessary. To replace it came such useful material as asphalt concrete. Today, there are several types of it, and one of the most popular is cast asphalt. You can buy this material on our website.

Composition and key features

As in classic asphalt, the same ingredients are used in the cast: sand, gravel, gravel and bitumen. The main feature is their ratio. In paved asphalt, the proportion of bitumen is increased to 13%. Also, when laying such asphalt, the operating temperature should be in the range of 200-250 degrees Celsius.

This species got its name because of the viscous consistency when heated. Due to this quality, it is used to cover prepared surfaces, such as roads and sidewalks. The resulting mixture spreads over the entire area without any problems, due to which it does not need additional compaction.

The key characteristics of cast asphalt include:

• wear resistance;
• water resistance;
• durability;
• relatively low price for cast asphalt.

It is also worth noting separately that the material independently acquires an operational density after cooling. Due to this, there is a reduction in costs during installation and increases speed road construction. The surface of the cast asphalt is characterized by high roughness, therefore it provides excellent adhesion for car tires. This advantage is especially noticeable during rain or snow.

Scope of application

The characteristics of cast asphalt make it possible to use it in solving a wide range of problems. It is actively used in the construction of roads, bridges, tunnels and other facilities. Also, cast asphalt concrete can be used in the construction of the lower and upper layers of sections of highway, highway or airdromes under construction.

Cast asphalt is used not only in construction, but also in any type of repair, in particular, to form a leveling layer, to repair potholes. Cast asphalt concrete has a number of waterproofing properties, so it is used in an atypical sphere - when arranging roofs and floors.

High quality cast asphalt

In the RAMON Construction Company, you can inexpensively buy first-class cast asphalt. On the page of our site you can find out the cost of cast asphalt. Our company uses only quality ingredients for the production of pavement. We are looking for an individual approach to each client. Order cast asphalt at LLC Ramon SK!

P 54401-2011 “Hot asphalt concrete road. Technical requirements"Cast asphalt concrete mixture -" cast mixture, with a minimum residual porosity, consisting of a grain mineral part (crushed stone, sand and mineral powder) and viscous oil bitumen   (with or without polymer or other additives) as a binder, which is laid using injection molding technology, without compaction, at a temperature of the mixture of at least 190 ° C. " Cast asphalt, depending on the temperature, as well as the magnitude and time of application of the load, manifests itself as an elastic-elastic and visco-plastic material. The difference between cast polymer-asphalt concrete is that they are produced using bitumen modified with polymer additives, a polymer-bitumen binder (hereinafter referred to as PBB).

Application in various countries

The prototype of cast asphalt concrete can be considered natural asphalt, which was used in Babylon and Nineveh. This material began to be used in European cities at the beginning of the 19th century. To do this, bitumen-containing limestones found in deposits in France (Seyssel), Germany (Limmer) and Switzerland, containing from 5 to 20% natural bitumen or heavy oil, were used. For the "cooking" of natural asphalt used large metal boilers, the mixture was laid manually. In 1829, cast asphalt was paved for the first time in Lyon, and then in large metropolitan cities (London and Paris), the laying of sidewalks and bridges with cast asphalt began. The use of the new coating had both positive and negative properties. Pedestrian townspeople were unhappy with smoking asphalt boilers and outskirts sticking to the asphalt in the summer heat. However, the use of cast asphalt has significantly reduced the noise during the movement of horses and wagons. In the crews themselves, conversation became possible. On the streets where the asphalt was poured, the traffic became so quiet that the sudden appearance of the crew frightened the townspeople, who were accustomed to the rumble of the approaching carts.

In the 1910-1950s. XX century cast asphalt found the greatest use in Germany, where they continued to improve the methods of laying, selection of formulations, the scope of application of the material expanded. In 1908, the first cast asphalt concrete was laid in Berlin and Frankfurt am Main. Since the late 1920s in the compositions cast mixtures   Trinidad asphalt from Peach Lake began to be used. In the early fifties, the first paver for cast asphalt concrete was invented. In the fall of 1954, in Berlin on the Ziemensstraße, the mechanized laying of cast asphalt concrete was first tested. Already in the 1960s, cast asphalt was laid seamlessly, up to 12 meters wide, and its use shifted towards the construction of express roads. The largest object for that time in cast asphalt concrete paving was the 38-kilometer section of the Nuremberg-Frankfurt Autobahn from Tenneloe to Schlusselfeld. The so-called “Berlin recipes” used, saturated with crushed stone, provided high roughness and long-term wear resistance. The then applicable TVbit6 / 60 standard provided for the use of bitumen with penetration from 15 to 65 units for cast asphalt concrete, or a mixture of road bitumen and natural Trinidad asphalt. Previously used for surface treatment, natural sand began to be replaced by gravel treated with bitumen.

The Russian history of the use of cast asphalt is primarily associated with the discovery and development of natural deposits of bitumen-containing dolomites in the Volga region, in the Syzran region. Deposits by reserves were estimated at 22 billion. pounds. Asphalt business developed in Russia since when D.I. Voeikov, together with zoologist M.N. Bogdanov, discovered sandstone soaked with natural bitumen in the Syzran district. This made it possible to establish the production of tar and mastic from local materials of excellent quality. Syzran asphalt was stronger than Western European analogues and melted at a higher temperature. Natural asphalt (bituminous rocks) was processed in significant quantities for mastic in factories near the village. Farm laborers and with. Pechersky Syzran district, including for casting briquettes, then melted at the place of laying in boilers. Both plants in the city produced 800 thousand pounds of mastic. Simbirsk asphalt was cheaper than foreign (at the beginning of the 20th century. 1 pood on average cost 35 kopecks), and was considered the best in Europe in quality. At the end of the 19th century - beginning of the 20th century Asphalt was bought by such cities as Moscow, Kiev, Nizhny Novgorod, Saratov, Astrakhan and others. All of the above types of cast materials had a distant resemblance to the compositions currently used, however, the practice of improving them, searching for the optimal ratios of the mineral part and bitumen, and additional introducing sand and gravel continued to develop.

Several research centers have been involved in modern research on cast asphalt in the USSR. However, unlike West Germany, cast asphalt concrete did not receive widespread use in the USSR. Development of compositions and technology for the use of cast asphalt concrete, studies of stress-strain states of a multilayer structure pavement   bridge structures were occupied by prominent scientists, experts - road builders and bridges of the State Unitary Enterprise NIIMOSSTROY, Moscow Automobile and Road State Technical University (MADI), Giprotransmost Institute, FSUE SoyuzdorNII, Saratov State Technical University and many others.

Classification

The main principles for the classification of cast asphalt concrete are their separation according to the size of the largest particles used in the composition of the mineral material (fractions of crushed stone); the purpose of the composition; styling method. As a rule, the first of the three principles listed is used in world practice. It is used in German, Swedish (BRO 94 “Basic technical and construction requirements for roads”, chapter 6), Austrian (ÖNORM EN 13108-6), Swiss (SN 640440), Russian standards, as well as in European standards of the EN series. Classification based on the styling method (manual or mechanized) applied in Finnish normative documents   . For example, the German classification of cast asphalt concrete according to the harmonized German standard TL Asphalt-StB 07 includes 6 main types: MA 11S; MA 8S; MA 5S; MA 11N; MA 8N; MA 5N.

In traditional compacted asphalt concrete, the so-called macrostructure (the content and shape of crushed stone and sand) plays a significantly larger role in the formation of the physical and mechanical properties of materials. The increased ABB content causes the fluidity of the cast mixtures, which, with the correct composition, allows us to consider this material almost as a viscous liquid that cannot be densified.

Source Requirements

In Russian national standard   on cast asphalt concrete (GOST R 54401-2011) sets out the requirements for the main components of this material.

Properties of Cast Asphalt

Cast asphalt concrete is low-combustible, does not spread flame, has a half thermal conductivity coefficient compared to concrete (0.7-0.9 W / mK), and is vapor and sound insulating materials (noise reduction up to 14 dB with a layer of 35 mm). The main advantages of cast asphalt concrete over traditional compacted asphalt concrete, produced according to GOST 9128-2009, are water resistance and fatigue life, the value of which increases several times when using road bitumen modified with thermoplastic elastomers.

Disadvantages of cast asphalt: increased cost of mixtures; the need for special equipment for the delivery and laying of material; poor resistance to plastic rutting with unsatisfactory quality of selection of the composition in the laboratory or technological production errors; cracking in winter period time when using unmodified bitumen in cast mixtures with a reduced penetration rate (less than 50 units) and an increased fragility temperature according to Fraas.

Green cast asphalt concrete with embossed pavers.

Demonstration laying cast asphalt mixture on vertical surfaces.

Scope of cast asphalt concrete

   Widespread in Germany have received coatings in residential and industrial premises, including in medical institutions. Such coatings, prepared on the basis of brittle bitumen, have high bending strength, low thermal conductivity, environmental friendliness and lack of smell and dust formation. Cast asphalt concrete, laid in a thickness of 20 to 35 mm, is used in combination with dense heat and sound insulation materials on concrete and wooden floors. On top of such coatings lay linoleum, carpet or ceramic tiles. Cast asphalt for flooring in Germany is subject to technical regulation.

The expansion of the use of cast asphalt in Russia was largely facilitated by large bridge projects in which pavement and waterproofing systems were arranged using cast asphalt. This is the construction of a bridge across the Volga in with. Pristannoe (2000), Ladoga bridge across the river. Neva by Marino (1998), the construction of the Bolshoi Obukhov bridges of the cable-stayed system in St. Petersburg (2004, 2007), the reconstruction of the Troitsky bridge across the Neva River in St. Petersburg (2002), the Blagoveshchensky bridge in St. Petersburg (2008), the construction of flyover systems on the Ring Road around St. Petersburg (2008-2010), the construction of the Ulyanovsk bridge over the Volga River (2009) and dozens of other objects.

The lower coating layer of the bridge of cast polymer-asphalt concrete.

The practice of operating artificial structures shows that the resource of longevity pavement   on some large bridges in Russia it is reduced by half in 2-5 years. The destruction of the coating layers of the bridge web leads to the intensive penetration of moisture, chemicals, debris directly to the waterproofing layers and damage to the latter. The unsatisfactory condition of the carriageway of bridges is one of the reasons for the destruction of structural elements of concrete artificial structures, as well as the corrosion of metal in orthotropic plates of the carriageway of metal bridges.

One of the reasons for the fragility of coatings is the use of a traditional multilayer structure on concrete spans consisting of dissimilar materials: two coating layers of traditional compacted asphalt concrete (at least 90 mm thick) in accordance with GOST 9128-2009 and a reinforced concrete screed covering the waterproofing layer. The water resistance of such a coating system and the degree of adhesion between the layers are negligible, which creates increased internal stresses in the materials. Operation of bridge structures in harsh climatic conditions, in conditions of vibration and exceeding permissible traffic loads leads to premature destruction of such systems and significant costs for their repair

In SP 35.13330.2011. Set of rules. Bridges and pipes. The updated edition of SNiP 2.05.03-84 * regulates the possibility of using cast asphalt concrete as coating materials for the lower and / or upper layers of the pavement of bridge pavement on concrete and metal spans. The document does not reflect the requirements for the type of bituminous binder used in cast asphalt, and the use of compacted mixtures on PBB is prohibited. This prohibition does not comply with the European practice of using polymer-modified bitumen, limits the practice of its use in the Russian Federation, and also potentially reduces the durability of coatings, taking into account the harsh climatic conditions of Russia. Due to their inherent physical and mechanical properties, cast asphalt concrete and cast polymer-asphalt concrete are widely used in the world practice of bridge building as coating materials for the roadway of a bridge. Their use on concrete bridge structures allows you to abandon the traditional design with concrete screed, which reduces the load on the spans and increases the service life of the coatings. In many EU countries (Germany, Austria, the Netherlands, Hungary, Finland, Sweden, etc.), cast asphalt concrete is also considered an important element of the waterproofing system, applied directly to the main waterproofing material and ensuring the joint work of the coating and spans due to the high degree of adhesion.

German national regulations on the installation of coatings and waterproofing of artificial structures, require the mandatory use of cast polymer-asphalt concrete as a protective layer of waterproofing. In Germany, the use of a multilevel waterproofing system on metal and concrete bridge constructions consisting of a primer (bitumen-containing or epoxy), a protective-bonding layer (a deposited roll web or polymer-bitumen substance) and cast asphalt concrete allows us to expect the service life of such systems without overhaul   up to 30 years or more.

Statistics

Annually, according to the European Association of Manufacturers of Cast Asphalt Concrete (hereinafter EMAA), from 800 thousand to 1 million tons of cast are produced in Europe asphalt mixes. Since 2004, Russia has been included in the EMAA. The largest European countries producing cast asphalt are Germany (389728 tons in 2009) and France (216505 tons in 2009), providing more than half of the annual total output. About 50% of all cast asphalt concrete manufactured in Europe is used as a waterproofing material, including as an element of a waterproofing system for bridge structures.

Surface treatment with blackened gravel of the upper layer of the coating of cast asphalt

Test methods

At the moment, in Russia, the list of methods for testing cast asphalt concrete is determined by the standards of organizations developed by manufacturers and technical specifications, the obligations of which the manufacturer assumes. Cast asphalt in Russia is tested for the value of the porosity of the mineral core, residual porosity, water saturation, determination of the tensile strength at split at 0 0 C, the compressive strength at 50 0 C, workability. In the EU countries, requirements for cast asphalt concrete contain functional requirements and, as a rule, do not contain specific digital values \u200b\u200bof indicators of indicators of physical and mechanical properties, limiting themselves to classification according to a large number of quality criteria. The final value of one or another indicator of the properties of cast asphalt is determined in the design documentation for the construction object or can be declared by the national annexes to the European standard (Nationally Determined Parameters), as well as by the manufacturer. The main method in determining the rheological properties of cast asphalt in most countries of the world is to determine the depth of indentation (penetration) in a sample of a flat stamp with an area of \u200b\u200b5 cm2. at constant vertical load (52.5 kg). The test is carried out on cubic samples of material measuring 7.07 x 7.07 x 7.07 cm at a temperature of +40 0 C, for 30 minutes. The magnitude of the deformation of the sample under the influence of a load is measured with an accuracy of 0.01 mm. The European test methodology is based on the German method described in DIN 1996, chapter 13.

The device for determining the depth of indentation of the stamp

Technical regulation

In May 2012, Russian standards for cast asphalt concrete were put into effect -