【Daily Discussion】Utilities - Civil Engineering - 20210604

The main properties include high-temperature stability, low-temperature crack resistance, water stability, fatigue resistance, and aging resistance.

Water resistance: Asphalt is a hydrophobic material that is insoluble in water; its structure is very dense, giving it excellent water resistance. Viscosity and plasticity refer to the ability to resist deformation under external forces, with their magnitude expressed by penetration. The ability to deform under external forces without breaking, with its magnitude expressed by the degree of elongation

Waterproof asphalt is a hydrophobic material that is insoluble in water; it has a very dense structure, resulting in excellent waterproof properties

The main properties of asphalt are as follows: Waterproof asphalt is a hydrophobic material that is insoluble in water and has a very dense structure, resulting in excellent waterproofing capabilities. The ability to resist deformation under viscous external forces, whose magnitude is expressed by penetration. The ability to deform under plastic external forces without breaking, with its magnitude expressed by elongation. Temperature stability refers to the property of asphalt in terms of its viscosity and plasticity changing with temperature, and its quality is indicated by the softening point. Atmospheric stability is the ability of asphalt to resist aging under the influence of atmospheric factors. The flash point is the temperature at which ignition occurs.

Asphalt is a dark brown, complex mixture composed of hydrocarbons with different molecular weights and their non-metallic derivatives; it is a type of organic liquid with high viscosity, remains in liquid state, has a black surface, and is soluble in carbon disulfide. Asphalt is an organic binding material that provides waterproofing, moisture resistance, and corrosion protection. Asphalt can be mainly divided into three types: coal tar pitch, petroleum asphalt, and natural asphalt. Among them, coal tar pitch is a by-product of coking. Petroleum asphalt is the residue remaining after the distillation of crude oil. Natural asphalt, on the other hand, is stored underground, sometimes forming mineral deposits or accumulating on the Earth’s surface. Asphalt is mainly used in industries such as coatings, plastics, and rubber, as well as for road paving. Petroleum asphalt is the residue remaining after the distillation of crude oil. Depending on the degree of refinement, it appears as a liquid, semi-solid, or solid at room temperature. Petroleum asphalt is black and shiny, with a high temperature sensitivity. Petroleum asphalt can be classified according to the following systems: by production method, it includes straight-run asphalt, solvent-deoiled asphalt, oxidized asphalt, blended asphalt, emulsified asphalt, modified asphalt, etc ； Based on their physical form, they are classified into: liquid asphalt, solid asphalt, diluents, emulsions, modified products, etc ； Classified by use: road asphalt, construction asphalt, waterproof and moisture-proof asphalt, and various specialized asphalts named according to their use or function, etc.

Three key indicators: needle penetration, elongation, and softening point. 1. Penetration: It is expressed as the depth to which a standard needle of specified mass of 100 g penetrates into the asphalt sample within a specified time of 5 s at a specified temperature of 25°C (1/10 mm per degree). The greater the penetration, the softer the asphalt and the lower its viscosity. 2. Ductility: It is determined using a ductility tester. An asphalt sample is placed in an 8-shaped standard mold, and the elongation length at the point of fracture, under a specified stretching speed (5 cm/min) and specified temperature (25°C), is expressed in centimeters. The higher the ductility value, the better the plasticity. 3. Softening point: Determined using the Global method. The asphalt sample is placed in a copper ring of specified dimensions (diameter 16 mm, height 6 mm); a standard steel ball is placed on top of the sample. The mixture is then immersed in water and heated at a specified rate (5°C/min). A higher softening point indicates better heat resistance.

This post was last edited by wjl7212 on 2021-6-4 at 14:25. It exhibits good adhesion to the surfaces of many materials, is hydrophobic, has a dense structure, and is resistant to corrosion

The key indicators of asphalt performance include penetration, ductility, and softening point. Asphalt is a dark brown complex mixture composed of hydrocarbons with different molecular weights and their non-metallic derivatives; it is a type of organic liquid with high viscosity, remains in liquid state, has a black surface, and is soluble in carbon disulfide. Asphalt is an organic binding material that provides waterproofing, moisture resistance, and corrosion protection. Asphalt can be mainly divided into three types: coal tar pitch, petroleum asphalt, and natural asphalt. Among them, coal tar pitch is a by-product of coking. Petroleum asphalt is the residue remaining after the distillation of crude oil. Natural asphalt, on the other hand, is stored underground, sometimes forming mineral deposits or accumulating on the Earth’s surface. Asphalt is mainly used in industries such as coatings, plastics, and rubber, as well as for road paving. The main technical parameters include: penetration, ductility, softening point, density, relative density, suitable climate zone, flash point, solubility, dynamic viscosity, penetration index, etc.

The main properties include high-temperature stability, low-temperature crack resistance, water stability, fatigue resistance, and aging resistance.