Horizontal road surface marking

Abstract

Road markings made of special materials with reflective additives (micro-glass beads) that increase the retroreflection factor of the road marking independent of the color (whiteness, brightness) of the road marking material (thermoplastic, cold plastic, paint). Light sources, such as car headlights, emit radiation, including in the form of visible light. A major portion of the light beams directly incident onto a pavement (6) is absorbed. According to the first embodiment, a portion of all incident light beams is partially reflected directly from a road marking layer (4) and returned in the opposite direction. In both embodiments, a portion of the light beams is incident upon an extending portion (1). Since no additional layer (8) is present on the surface of the extending portion (1), the light beam is partially reflected and, upon refraction, passes inside a micro-glass bead (2). Having passed through the micro-glass bead (2), the light beams are almost completely reflected from the interface between the glass and additional layer (8), which is present along the entire surface of the micro-glass bead (2), except for the extending portion (1). Most of these reflected light beams is returned to the light source.

Claims

1. Horizontal road markings comprising a road marking layer with a first surface and a second surface, where the first surface faces transport moving along the road surface, and the second surface is placed on the road surface; and micro-glass beads located on said road marking layer partially embedded in said road marking layer such that there is an extending portion of the micro-glass beads located above the first surface, wherein said micro-glass beads within the road marking layer are provided with an additional layer of removable, water soluble paint completely covering their entire surface, said additional layer being dissolvable when exposed to precipitation, UV radiation, or chemical reagents, such that said extending portion becomes a clean glass surface when said road markings are in use.

2. The road markings according to claim 1, wherein the additional layer is a water-based paint.

3. The road markings according to claim 1, wherein the additional layer is a metal-based paint.

4. Horizontal road markings comprising micro-glass beads located on a surface of pavement facing transport moving along the road surface, where said road surface at least contains bitumen, and micro-glass beads are partially embedded into the bitumen so that there is an extending portion of the micro-glass beads located above said road surface, wherein the extending portion of the micro-glass beads are provided with an additional layer of removable, water soluble paint completely covering their entire surface, said additional layer being dissolvable when exposed to precipitation, UV radiation, car tire friction, or chemical reagents such that said extending portion becomes a clean glass surface when said road markings are in use.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is illustrated by the drawings (FIGS. 1-2), where FIG. 1 shows the cross-portion of the pavement with the road markings applied thereto; and FIG. 2 shows the cross-portion of the pavement made of asphaltic concrete with applied micro-glass beads (the size ratio in the drawings is conditional).

INDUSTRIAL APPLICABILITY AND EMBODIMENTS OF THE INVENTION

(2) In case of using the above elements, the invention is implemented as follows.

(3) First, the micro-glass beads (2) are coated with additional layer (8) by using a certain technique, such as spraying or dipping.

(4) To lay the road surface (6), asphaltic concrete mixture is prepared from mineral grains (9) and bitumen (10). Laying and compaction of the asphaltic concrete mixture is performed by using, for example, an asphalt paver and a road roller (in accordance with par. 12.3 of the Set of Rules 78.13330.2012 “Automobile roads” approved by order No. 272 of the Ministry of Regional Development of the Russian Federation (Minregion of Russia) on Jun. 30, 2012).

(5) According to the first embodiment, the road marking layer (4), which is usually less than 6 mm thick (according to par. 5.3 of GOST R 51256-2011 “Road marking. Classification. Technical requirements”) and has an established configuration (according to appendices A and B of GOST R 51256-2011 “Road marking. Classification. Technical requirements”), is applied to the road surface (6). The road marking layer (4) is applied, for example, by using a special road-marking machine or manually. As a result, the first free surface (3) and the second surface (5) facing the road surface (6) are formed. The micro-glass beads (2) with additional layer (8) on their surface are applied to the first surface (3) of just applied (non-hardened) road marking layer (4) by using, for example, a pneumatic distributor of the road-marking machine. If the material of the road marking layer (4) has low viscosity, micro-glass beads (2) sink under their own weight. If the material of the road marking layer (4) is more viscous, micro-glass beads (2) are embedded by providing kinetic energy, for example, by using compressed air.

(6) According to the second embodiment, the micro-glass beads (2) with additional layer (8) on their surface are applied onto just laid road surface (6) by using, for example, a pneumatic distributor of the road-marking machine. The micro-glass beads (2) with additional layer (8) on their surface can also be applied to a fully finished (with solidified bitumen (10)) road surface (6) by pre-heating said road surface (6) until bitumen (10) softens by using, for example, a stream of hot air. The micro-glass beads (2) are then embedded in bitumen (10) by providing kinetic energy, for example, by using compressed air.

(7) As a result, the additional layer (8) becomes located between the micro-glass beads (2) and the material they were embedded into (material of the road marking layer (4) according to the first embodiment, and bitumen (10) according to the second embodiment). The micro-glass beads (2) are embedded partially. A non-immersed portion of the micro-glass beads (2) forms the extending portion (1). While embedding, microvoids (7) may form around the micro-glass beads (2) (with additional layer (8) on their surface). These microvoids (7) are located between the additional layer (8) and the material which micro-glass beads (2) are embedded into (material of the road marking layer (4) according to the first embodiment, and bitumen (10) according to the second embodiment). The micro-glass beads (2) with additional (not yet removed) layer (8) on the surface of the extending portion (1) are shown in FIGS. 1 and 2 on the right.

(8) External factors (precipitations or UV radiation, exposure to car tires, chemical reagents) remove the additional layer (8) from the surface of the extending portion (1). In one instance, precipitations dissolve the material of the additional layer (8). The resulting solution flows down from the surface of the extending portion (1). In another instance, additional layer (8) is removed by the car tire treads due to mechanical impact. Mechanical removal is easily achievable due to insignificant adhesion forces between the additional layer (8) and the glass surface of the extending portion (1). As a result, in both instances, the surface of the extending portion (1) represents a clean glass surface. Micro-glass bead (2) after the additional layer (8) has been removed by the natural factors from the surface of the extending portion (1) is shown in FIG. 1 on the left and in FIG. 2 as first and second on the left.

(9) The invention is used as follows. Light sources, such as car headlights, emit radiation, including in the form of a visible light. Majority of the light beams directly hitting the road surface (6) are absorbed. According to the first embodiment, a portion of all incident light beams is partially reflected directly from the road marking layer (4) and returns in the opposite direction. In both embodiments, a portion of light beams is incident upon the extending portion (1). Since the additional layer (8) is no longer present on the surface of the extending portion, the light beam is partially reflected and, upon refraction, enters the internal volume of the micro-glass bead (2). The light beams that have passed through the micro-glass bead (2) get almost completely reflected from the interface between glass and additional layer (8) located on the entire surface of micro-glass beads (2), except for the extending portion (1). Majority of these reflected light beams return to the light source.

(10) In the prototype, however, the light beams undergo additional absorption by the layer of transparent glue, and a portion of the light beams that have passed through the micro-glass beads (2) enters the microvoids (7) between the surface of the micro-glass bead (2) and material of the road marking layer (4), where the light gets absorbed or scattered. Due to these factors, in case of the prototype, when the light beam returns to the light source, it is significantly weakened.

(11) Thus, by using additional layer (8), an increase in the portion of returned light beams incident onto the extending portion (1) of the micro-glass beads (2) provides a better visibility of the road markings. The retroreflection factor and color of the reflected light are independent of the color of the road marking material and are determined only by the additional layer (8). Hence, there is no need to use high-whiteness materials in order to increase the retroreflection factor of white markings.

(12) In case, when some road marking elements should be informative only during the dark part of the day, or if there is a need to change the color of the road surface before a dangerous portion, micro-glass beads (2) can be applied directly to a freshly laid asphaltic concrete by embedding them by ½ to ⅔ into a not yet cooled layer of bitumen (10), or by pre-heating the required portion of asphaltic concrete (i.e., according to the second embodiment).