Development of nanocomposite materials for road construction

. The level of economic development of any state can be determined today by the quality of roads. Consequently, a wide variety of projects and concepts have appeared in almost many countries recently, which radically change the idea of roads. Reliability and safety of delivery of various cargoes largely depends on the quality of construction and repair of modern road surfaces. Road works related to their various types (replacement of the canvas, marking) cannot be carried out without additional signs and fencing devices. This article discusses the possibility of replacing the polymer matrix that forms the basis of fencing devices (plastic cones, road barriers) with polytetrafluoroethylene (PTFE) using a reflective component. As a reflective component, it is proposed to use a photoluminophore, which is capable of converting absorbed energy into light radiation, providing continuous light emission for 10 hours. The main criterion of this material is its light output in the dark.


Introduction
In the modern world, the term smart city is interpreted in different ways. The areas of "smart city" include: transport, energy, utilities, urban environment, security, "smart home".
Analyzing the problems of all major cities, one of the most important is traffic congestion. Therefore, in many countries, such a concept as "smart roads" has been introduced . The development of transport systems is currently associated with the development and implementation of innovative technologies in the transport system. The construction of "Smart roads" in many countries is given the closest attention. Smart roads will not only improve safety, but also provide an opportunity to intelligently manage traffic flows, improve the quality of driver service and collect the necessary data for the further development of road transport infrastructure [1][2][3][4].
In Russia, the following companies make a great contribution to the creation of smart roads: MADI, Taganrog University, state-owned Innopolis, Aurora Design Bureau and private business Yandex, KamAZ [5].
China is a leader in technological progress, annually demonstrating its new technological developments to the world. In the city of Jinan, Shandong Province, a new "smart" road is being built, equipped with solar panels that will charge cars passing through it with an electric motor wirelessly [6][7].
In France, the Wattway road, completely covered with solar panels, has been developed and partially erected. A unique road was recently opened in Sweden. It is equipped with a special contact rail, to which an electric car is connected through a current collector. The company New Energy Technologies, USA, has created a device capable of collecting kinetic energy of moving vehicles [6].
The level of economic development of any state can be determined today by the quality of roads. Consequently, a wide variety of projects and concepts have appeared in almost many countries recently, which radically change the idea of roads [8].
The introduction of new materials and technologies in the field of road construction makes it possible to implement financial programs aimed at transforming and improving the quality of roads. A modern road should no longer be perceived as a separate element of construction, but a bright integral element of the entire architectural and construction complex, emphasizing the beauty and uniqueness of the interior of the city [9][10][11].
Modern highways of the Russian Federation are the logistical arteries of its economic development. Reliability and safety of delivery of various cargoes largely depends on the quality of construction and repair of modern road surfaces. Road works related to their various types (replacement of the canvas, marking) cannot be carried out without additional signs and fencing devices. As a material used recently for the manufacture of such parts are polymers. They have unique, necessary properties that ensure reliable operation in extreme conditions.

Materials and methods
Today, cities are simply forced to change due to rapid urbanization, simplification of traffic, reduction of environmental pollution and increased safety. The introduction of smart road technologies helps city and state authorities to solve these problems without delay.
A new generation of so-called "Smart Roads", independently ensure their functioning by power supply, draw markings depending on road conditions, glow in the dark, warn drivers about the appearance of dangerous areas, monitor the state of traffic, respond to emerging problems, charge electric vehicles when they move, etc., that is, equipped with all the latest achievements science and technology. [12].
One of the first ideas in the development of new innovative roads was the application of road markings using special photoluminescent paint, which was developed by Dutch designer Daan Roose gaarde with the assistance of Heijmans.

Results
Currently, in industrially developed countries, the production of products made of polymer composite materials is steadily growing, since these materials make it possible to significantly improve the quality and reduce the weight of products and structures, including those working in extreme conditions, while increasing their reliability and resource. Rapid progress in this field has led to the emergence of a large number of diverse polymer materials and methods for their production [12].
Thus, plastic cones are needed for road construction, (Fig.1) and road barriers (Fig. 2), providing separation and fencing of places where road works are carried out.  Recently, the material used for the manufacture of the signal cone is plastic with an operating temperature range from -50 to + 600C. Such a material is subject to mechanical destruction, especially in winter, even under low loads [13][14][15].
This article discusses the possibility of replacing the polymer matrix, which is the basis of the product, with polytetrafluoroethylene (PTFE) using a reflective component, a substance capable of converting absorbed energy into light radiation, providing continuous light emission for 10 hours.
To create an experimental model, polytetrafluoroethylene powder was used (Fig.3), in the amount of 98.0% by weight and photoluminophore of the FV-530D brand with yellowgreen light reflection, particle size 18-30 microns and a glow time of 10-12 hours (Fig.4).  The components for creating a test sample were individually prepared using the method of mechanical activation in a high-speed mixer at a rotor speed of 7000-1ob/min, for 1.5 -2 minutes. Each component was evenly poured into the mold in turn, then the resulting composition was pressed at a pressure of 90-100 MPa.
The heat treatment of the composite material was carried out in a mold using the thermal limitation method at a temperature of 360 ± 100C (Fig. 5). The main criterion of this material is its light output in the dark. To do this, the material was exposed to sunlight for 3 hours and after that the sample was placed in a dark room to determine the time of light emission. Figure 6 shows a sample after 2 hours spent in the dark, and Figure 7 shows the same sample, but after 8 hours. Thus, the production of auxiliary materials for road construction from a composite material based on PTFE using photoluminophores is one of the promising directions.
Based on the work done, the study of the samples obtained, it can be concluded that the use of this material in road construction will be much more economical and profitable, which in turn will contribute to improving the environmental situation in the city. The road construction sector should develop with the use of innovations and modern technologies.