Comparison of concrete and paved roads, their advantages and disadvantages
In which city did the first asphalt road appear?
Asphalt was the first oil product that a man met. Natural asphalt - one of the types of natural bitumen - is a viscous resinous substance formed from heavy oil fractions as a result of prolonged weathering. It occurs in the form of stratified vein deposits, as well as lakes in places where natural oil emerges to the earth's surface. This is a solid fusible mass of black color, containing 25–40% of oils and 60–75% of resinous asphaltene substances. The word “asphalt” (from the Greek “asphales” - strong, strong, reliable) has been known since the time of Herodotus, who described Mesopotamian and Persian asphalt deposits in his History.
People found the use of natural asphalt at the dawn of civilization - in Ancient Egypt 5,000 years ago, the floor and walls in barns for storing grain were covered with asphalt. In Babylon, it was used as a binder in laying stone walls - the Bible says that when building the Tower of Babel, "earthen tar" was used, as the ancient name for asphalt. The same Babylonians used a layer of asphalt mixed with reed for waterproofing during the installation of the famous hanging gardens of Babylon. For 400-500 years BC, the walls of the fortress, as the ancient Greek historian Xenophon testifies, were built of bricks fastened with natural bitumen. In the same way, the first sections of the Great Wall of China were built on bitumen.
As for the more familiar to us road application asphalt, natural asphalt was used in the construction of roads in America, more than 500 years before such asphalt was used in Europe and the USA. When in 1532 a detachment of Spanish conquistadors led by Francisco Pizarro entered the territory of the Inca Empire, they were amazed, among other things, by the magnificent roads covered with asphalt.
But the great civilizations of the past perished, and asphalt as a building material was forgotten for centuries and millennia. Until the beginning of the 19th century, the streets of all the cities of the world were paved with stones at best, and only then did a new era begin in large cities - the era of asphalt. In 1832 - 1835 in Paris, the first work was done on paving city streets and sidewalks with asphalt.Further, in 1835-1840, the turn of London, Vienna, Lyon, Philadelphia and some other cities came.
In the Russian Empire, the first experience of using asphalt was taken in 1839, when in St. Petersburg they covered almost 100 meters of the sidewalk with a width of 1.5 meters near the Tuchkov Bridge. On a somewhat large scale, asphalt was used in 1865, when the terraces of the Winter Palace were paved. But as early as the next year, asphalt began to be widely used in ordinary St. Petersburg streets, squares and courtyards, and by 1880 he had covered many streets in Kronstadt, Moscow, Riga, Kharkov, Kiev and Odessa. True, the first asphalt plant was built in Russia only in 1873, a few miles from Syzran, and before that, asphalt was purchased abroad.
From the middle of the 19th century, in France, the USA, Switzerland and other countries, paving began to be made from bitumen-mineral mixtures. In the USA, cast asphalt prepared using oil bitumenfirst applied in 1876. Then, in 1892, the first 3-meter-wide road structure was built using the industrial method, and after another 12 years, 29 km of the road were built using a tarmac with free flow of hot bitumen.
For the rapidly developing road network, new types of pavements were needed, and asphalt turned out to be the most suitable material. It can be laid almost perfectly evenly, it has a very low-noise coating, but at the same time it has the necessary roughness. Modern roads are covered with asphalt made on the basis of petroleum bitumen obtained as a result of oxidation by air of heavy residues of oil distillation at a temperature of 239-340 ° С. This process was developed in 1896, and introduced into production in 1914.
Russian roads and their repair is one of the main topics of conversation not only for drivers, but also for ordinary passengers. Meanwhile repair pavement requires compliance with many rules. How the roads are paved, says M24.ru.
Moscow roads
In spring and summer, road repair traditionally begins. In Moscow and the region due to the large flow of transport roadbed quickly deteriorates. Where it cannot be completely replaced, partial patching is carried out.
Since 2011, new rules have come into force, according to which road repairs should be carried out not once every seven years, as it was before, but once every three years. According to officials, due to climatic conditions, the road in Russia lasts no more than three years.
History of asphalt
Asphalt in nature has been known since ancient times (another 600 years BC). Centuries ago it was called mountain tar. In our time, it is widely used throughout the world. Mostly it goes to cover roads. In industrial buildings, floors are made of it. Asphalt is used for the preparation of various varnishes, adhesives and other industrial materials.
Initially, in the XIX century, city streets were paved with stones, there were cobblestone pavements. First asphalt concrete pavement It was used to cover the sidewalks of the Royal Bridge in Paris in the 30s of the XIX century.
A little later, roads began to be covered with asphalt in Russia. In the summer of 1839, sidewalks and part of the bridge at the Tuchkov Bridge Dam were covered in St. Petersburg. For the first time, Russian asphalt was mined at the Syzran plant in 1873, on the right bank of the Volga 20 km higher than Syzran.
Asphalt can be both natural and artificial. The composition of natural asphalt includes heavy oil or its residues, which upon evaporation of its light elements and oxidation form the asphalt itself.
Artificial asphalt (or asphalt concrete) - a fairly dense mixture of bitumen, sand, mineral powder and crushed stone - is used for paving various areas of the earth's surface, including airfields. The price of this type of asphalt is much lower than natural, and therefore it is most widely used.
The text is based on materials from open sources
Galina Raspberry
Asphalt roads wear out faster than concrete roads, but in many countries concrete roads are replaced by asphalt roads, since they are cheaper, despite the fact that concrete roads have several advantages. In this article you will learn about the advantages and disadvantages of these materials for paving roads.
If you traveled from Pune to Mumbai, you probably saw a beautiful concrete expressway. Currently, in this area, almost all road construction uses concrete, not asphalt. However, some busy popular highways are still paved.
Benefits of Concrete Roads
- Durability and lack of need for repair: Concrete roads have a service life of more than forty years, while paved roads wear out over ten years. Moreover, during operation, concrete roads do not require frequent repairs, which are required for asphalt roads.
- Vehicles consume less fuel: A vehicle while traveling on a concrete road consumes 15-20% less fuel than when driving on an asphalt road. This is due to the fact that the concrete road does not deform under the wheels of loaded trucks.
- Concrete is resistant to automobile fuel leakage and extreme weather: Unlike asphalt roads, concrete roads are not damaged by the oils and fuels of vehicles or from extreme weather conditions, heavy rains or extremely high air temperatures.
- Concrete is more environmentally friendly than asphalt: When paving roads with asphalt (bitumen), severe air pollution occurs. In addition, less fuel consumption by vehicles traveling on concrete roads means less pollution.
- Savings natural resources: Asphalt (bitumen) is produced from oil, the reserves of which are reduced. Concrete (cement) is made from affordable limestone.
Disadvantages of concrete roads
- The cost of installation work: The cost of paving a concrete road is slightly higher compared to asphalt.
- Maintenance problem: If the concrete road cracks or deteriorates, the whole concrete slab must be replaced.
- Security system:In the rainy and winter seasons, vehicles are more likely to slip on a concrete road covered with precipitation.
Advantages of asphalt (bitumen) roads
- Profitability: Compared to concrete, the cost of asphalt is less. In addition, building an asphalt road takes less time, as the asphalt dries faster.
- Recycling: Asphalt is made from recycled materials. It can be used again.
- Simple maintenance: Only part of the road can be repaired. Asphalt roads can be laid on the old layer.
- Security: Asphalt roads provide better grip and slip resistance for vehicles.
The disadvantages of roads made of asphalt (bitumen)
- Low strength: heavy rain and other extreme weather spoil the paved roads, so they need frequent repairs.
- Environmental pollution:Melting asphalt produces a lot of harmful fumes. In addition, expensive oil is required to produce asphalt.
Conclusion
Concrete roads are highly durable and more environmentally friendly compared to asphalt roads. However, the cost of paving is much less than the cost of concreting. In addition, the asphalt road provides better grip and protects the car from slipping during snowfall.
Sourse of information:
Asphalt road has long become a familiar part of the modern landscape, which few people pay attention to. The network of roads stretched across almost the entire earth’s solid, improving the speed of communication between people. Observe how, for example, the road is paved. On the one hand, it is difficult to call such work high-tech. And on the other hand, knowledge of some of the nuances in the creation and operation of modern roads contributes not only to their strength and durability, but, in some cases, directly affects road safety.
A small digression into history
Asphalt has been known to our ancestors since ancient times. For example, the Dead Sea was called asphalt, and this name has been preserved almost to the present day. The deposits that were there were used not only for road construction, but also in shipbuilding and even mummification.
It is especially interesting to note the Spaniards, who drew attention to the excellent properties of the bituminous Lake Peach Lake, that the Natural asphalt mined in this place is still popular all over the world. Scientists have estimated the needs of mankind that this lake can provide at about 400 years, but there are 15 more deposits. The first paved road can rightfully be considered the coating of the Royal Bridge of Paris. In its creation used a bitumen-mineral mixture. "Fashion" has reached Russia. So, in St. Petersburg several road sections were paved. But the Americans really turned around, starting in 1876.
Where does the road begin
In what sequence is the road paved? Of course, it all starts with planning and design. They take into account interaction with other roads, drainage systems, traffic lights, crossings and many more nuances.
Training
This is perhaps the most time-consuming and responsible operation of the process. The quality of the asphalt road directly depends on the correct decision-making and control over the implementation of preparatory work. According to their specifics, preparatory measures differ depending on environmental conditions. In the city, they may not be so laborious, but outside the city there are options: the study of the presence of groundwater and other factors. For example, if you do not take into account the occurrence of groundwater, then the asphalt road can be washed and a collapse will occur.
The process itself is as follows: depending on the terrain, add sand or, on the contrary, cut off excess land with a bulldozer. The next most important moment is to give strength and hardness to the foundation for the road. There may be several options. Crushed stone with sand is added, and the fraction of crushed stone matters. Large crushed stone is used where a serious load on the road surface is expected, small crushed stone - on the contrary. Reinforced slabs can sometimes be used.
Side curbs serve several purposes at once: they fasten the roadbed, and are also a guide when creating it. After filling the “pillow” of sand and gravel, it must be tamped. It is impossible to carry out such work through the sleeves, since the quality of the asphalt road depends on the strength of the foundation.
The moment of acceptance of work performed
And here comes one of the most important points - the acceptance of hot asphalt. The very foundation of the road is properly cleaned and spilled with hot bitumen, which is rubbed over the entire area. Arrived hot asphalt usually falls out in one pile and manually shovels evenly distributed over the entire area of \u200b\u200bthe future coverage. Following the road workers distributing asphalt, people come with an interesting tool that vaguely resembles a mop, or, as builders call it, a “mashka”. Their task is to level the paved asphalt as much as possible.
The final chord is the paver, which slowly but surely completes this production process. This is a description of the manual method of laying asphalt. There is a second, no less efficient, with the participation of two special road-laying machines. The first distributes asphalt, replacing all manual labor. The second is the paver, which, following the first, brings the work to its logical conclusion.
Some observations
Watch the roads asphalt. Sometimes you can see very interesting things. For example, when laying occurs in rain and severe frost. Because of this, the quality of asphalt deteriorates sharply, because it is impossible to do such work in bad weather.
Heavy trucks ruthlessly crash roads, especially in cities where the paved road is not designed for such a load.
And, as they say in medicine, prevention and prevention are better than then long and exhausting treatment. This statement is true in relation to the rules of operation of the road surface.
Asphalt is a mixture of mineral materials (gravel and sand) and bitumen. In the bowels of the Earth it can be both in liquid and in solid form. When the temperature rises, it softens and becomes liquid, and when it decreases, it solidifies again. Carbon and hydrogen are in the asphalt; the latter, in turn, is part of the crude oil.
Types of asphalt
There are two types: natural, which lies near the surface of the earth, and artificial - it is produced in modern refineries from crude oil. Natural asphalt has a high bitumen content - from 60% to 75%, and in oil only 13-60%.
Very interesting is the fact that the largest “asphalt lake” is located on the island of Trinidad, it covers an area of \u200b\u200bforty hectares and goes deeper than more than thirty meters. When covering the streets of Washington, the US capital, with asphalt, most of it was taken from Trinidad.
Asphalt Lake Peach Lake, Trinidad
Asphalt is used for coating. highways, for roofing, for the manufacture of various varnishes, adhesives and putties, are also used as electrical and waterproofing material.
Heyday background
In the nineteenth century, the streets of the cities were originally paved with stones. In countries such as the USA, Switzerland, and France, from the mid-nineteenth century, bitumen-mineral mixtures began to be used for paving. The first cast asphalt based on petroleum bitumen appeared in the USA in 1876. Asphalt pavement became the “pioneer” of pavement in Paris in the 1930s with the installation and refinement of the Royal Bridge, and a little later for the bridge called Moran, which was thrown across the Rhone River in Lyon.
Road communications developed very rapidly and required new technologies and types that were built as quickly and easily as canvases from the ground.
For the first time, a roadbed was created by the industrial method in the USA in 1892, it was 3 meters wide and made of concrete. And in twelve years road constructions Already produced using a tarmac, through which hot bitumen flowed freely.
The pioneer in the mass production of asphalt in Russia was engineer I.F. Buttats. The first Russian factory to produce this road material was Syzransky (back in 1873).
The advantages of asphalt in the modern world
As it turned out, asphalt is an ideal material for covering roads, because it has a lot of advantages. Over time, he became smoother, which reduced the noise of the wheels. Unlike cement concrete, which was used earlier, asphalt concrete quickly dried up, hardened, gained strength and "allowed" to open the movement almost immediately. Cement-concrete required twenty-eight days for this.
In the modern world, asphalt is widely used and is the most popular coating material for various territories. One of the many advantages of this bituminous substance is its ductility and ability to bend rather than break. This is very important when creating runways, as sometimes the weight of the aircraft can exceed 140 tons. This quality is also significant in the creation of highways on which huge trucks drive, the weight of which can be more than forty-five tons.
The asphalt pavement is very practical, it is easy to repair, it holds any road markings remarkably, it is well washed and has the necessary stiffness to grip the wheels with the road.
Modern technologies do not stand still and continue to develop. This also applies to asphalt material, and methods for coating it. The ability to withstand great heat and severe cold, without fear of temperature extremes, has long been added to the list of pluses.
