Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Some properties of crushed stone for road surfaces
Summary On wet roads a sufficiently rough surface texture on the macroscale is necessary to ensure rapid removal of water from the contact zone between the tire and road surface, especially at high speeds. For this surface texture on the macroscale, beside the particle size of the aggregate also the resistance to crushing and abrasion is rather important. The macroroughness is likely to decrease rapidly in case of insufficient resistance to crushing which will cause destruction of stones at the surface. It decreases too, if the resistance to abrasion of stones, which protrude from the road surface, is poor. The texture depth, which is a measure of the roughness on the macroscale, can easily be determined. A satisfactory surface texture on the microscale is required as well, because this texture is at least largely determinant of the level of skid resistance. It is not yet possible to express the surface texture on the microscale in a number. The resistance to polishing of aggregates can, however, be expressed as the polished stone value which is determined in the laboratory using an apparatus for accelerated polishing. The correlation between the polished-stone value and the skid resistance, i.e. the similarity with practice, appears to be good in cases in which the surface consists of a continuous mosaic of coarse aggregate such as in surface dressings. Finally also the shape of the stone particles may be important for the skid resistance (unfractured faces in crushed gravel) and for the resistance to crushing (thin pieces).
Some properties of crushed stone for road surfaces
Summary On wet roads a sufficiently rough surface texture on the macroscale is necessary to ensure rapid removal of water from the contact zone between the tire and road surface, especially at high speeds. For this surface texture on the macroscale, beside the particle size of the aggregate also the resistance to crushing and abrasion is rather important. The macroroughness is likely to decrease rapidly in case of insufficient resistance to crushing which will cause destruction of stones at the surface. It decreases too, if the resistance to abrasion of stones, which protrude from the road surface, is poor. The texture depth, which is a measure of the roughness on the macroscale, can easily be determined. A satisfactory surface texture on the microscale is required as well, because this texture is at least largely determinant of the level of skid resistance. It is not yet possible to express the surface texture on the microscale in a number. The resistance to polishing of aggregates can, however, be expressed as the polished stone value which is determined in the laboratory using an apparatus for accelerated polishing. The correlation between the polished-stone value and the skid resistance, i.e. the similarity with practice, appears to be good in cases in which the surface consists of a continuous mosaic of coarse aggregate such as in surface dressings. Finally also the shape of the stone particles may be important for the skid resistance (unfractured faces in crushed gravel) and for the resistance to crushing (thin pieces).
Some properties of crushed stone for road surfaces
Hogervorst, D. (Autor:in)
1974
Aufsatz (Zeitschrift)
Englisch
METHOD OF CONSTRUCTING CRUSHED STONE STRUCTURE AND CRUSHED STONE STRUCTURE
| Europäisches Patentamt | 2018
| Engineering Index Backfile | 1938
| Engineering Index Backfile | 1953