Is the theoretical relative density of asphalt mixture with large gradation large?

What is graded large? Not that said.

In the case of the same material, the coarser the asphalt mixture aggregate, the greater the theoretical density.

Such as: AC-25> AC-20> AC-13> AC-10

The theoretical relative density is directly proportional to the density of the material.

The asphalt mixture mix design is divided into three stages: the design of the target stool standard mix, the design of the production mix and the verification of the production mix.

Although the work content of each stage is different, the final problem to be solved in each stage is the same, one is to determine the proportion of mineral materials, and the other is to determine the amount of asphalt. That is to say, asphalt mixture mix design is based on a technical work based on testing, inspection, adjustment and improvement, and only in stages, and combined with testing, construction equipment repeatedly verified, adjusted, in order to obtain satisfactory mix design results.

1. Target mix ratio.

The target mix design is basically completed in the laboratory, which is the basic work of the mixture composition design, including the raw material test, the mixture composition design test and the verification test, and the proposed mix ratio is called the target mix ratio. Specific design steps: (1) the determination of the mixture type and grading range (2) the selection and determination of raw materials (3) the selection of mineral gradation (4) the Marshall test (6) the road performance test (5) the determination of the optimal asphalt dosage.

2. Production mix ratio production mix ratio adjustment should be combined with the mixing building, there are two types of mixing buildings used in production at present, one is the continuous mixing building, as long as the flow rate adjusted to the cold bin meets the target mix ratio requirements, the mixing material can be heated, and the production mix ratio design is not required; The other type is the batch mixing building, which heats and screens the aggregates, and then weighs and matches them in each hot silo, and the proportion of the backing is the production mix ratio. Due to the matching ratio of the ore material of each hot silo, the matching ratio of each ore material with the target mix ratio will be different, so it is necessary to determine the matching ratio of the ore material of each hot silo through the test, and the secondary gradation is called on site. The purpose of adjusting the production mix ratio is to adjust the flow rate of each cold silo to meet the requirements of the design synthesis gradation on the basis of the target mix ratio, and to determine the mix ratio of the ore in each hot silo for the batch mixing building.

The specific design steps: (1) the adjustment of the flow rate of the cold silo (2) the determination of the proportion of ore material in each hot silo (3) the determination of the amount of asphalt.

3. Production mix verification The target mix ratio is completed in the laboratory, although the production mix has started the mixing building, but there is no formal mixing, and the production standard mix needs to be formally mixed in the design stage, and the test road is paved. At the same time, the mix ratio is further adjusted, and the mix ratio is finally determined as the basis for production control and quality inspection, which is called the production standard mix ratio. The production standard mix ratio is mainly to solve two problems:

Determine the mixing temperature and analyze the mixture material and properties.

For more information, you can refer to the book "Asphalt Pavement Construction Technology and Quality Control", which has specific practices, design requirements and solutions.

Calculation formula analysis

1. Asphalt mixture porosity = (1-specimen gross bulk density maximum theoretical density) * 100%, unit%.

2. Asphalt saturation = (ore clearance rate - void ratio) VMA * 100%, unit%.

3. Ore clearance rate = [1 - (gross bulk density of specimen Synthetic gross bulk density of ore material) * (mass percentage of ore 100)] * 100%, unit%.

4. The maximum theoretical density = 100 [(100 effective relative blind density) + (asphalt dosage of asphalt 25 density)], unit g mm3.

Physical property analysis.

A complex black-brown mixture of hydrocarbons of different molecular weights and their non-metallic derivatives, it is a type of high-viscosity organic liquid, which is liquid and has a black surface, soluble in carbon disulfide mills and pies. Asphalt is an organic cementitious material that is waterproof, moisture-proof and anti-corrosion.

Asphalt can be divided into three main types: coal coke asphalt, petroleum asphalt and natural asphalt: among them, coal coke asphalt is a by-product of coking. Pengxian petroleum bitumen is the residue after distillation.

Natural bitumen is stored underground, and some form layers or accumulate on the surface of the earth's crust. Asphalt is mainly used in coatings, plastics, rubber and other industries, as well as paving roads.

A maximum theoretical density tester for asphalt mixtures is used.

1. According to the regulation T0701 asphalt mixture sampling method or take (or drill) asphalt mixture samples from the asphalt pavement. The number of specimens shall not be less than the number specified below. The nominal maximum particle size (mm) and the minimum number of samples (g) of aggregate in asphalt mixture.

2. Carefully disperse the asphalt mixture aggregate, the coarse aggregate is not broken, and the fine aggregate aggregate is dispersed to less than, if the mixture is hard, it can be properly heated in the oven and dispersed, and the general heating temperature does not exceed 60 °C, and the dispersed sample should be broken by hand, and shall not be broken with a hammer to prevent the aggregate from being broken and the aggregate from being broken. When the specimen is a non-dry mixture taken from the road surface, it should be dried by an electric fan to a constant temperature before operation.

3. Negative pressure container type A, pressure-resistant glass, plastic or metal tank, with a volume of more than 1000ml, with a sealed cover, connected to a vacuum hose, and connected to a vacuum pump.

Summary. The mix ratio of pro-asphalt mixture is mainly determined by the following factors:1

Asphalt quality: Different asphalt quality has different requirements for the mix ratio of the mixture; 2.Aggregate Quality:

Different aggregate quality has different requirements for the mix ratio of the mixture; 3.Place of use: Different places of use have different requirements for the mix ratio of the mixture, such as highways, urban roads, airport runways, etc.; 4.

Sieve gradation: different gradations of asphalt mixture have different requirements for the mix ratio of the mixture;

What is the ratio of rubber 13 asphalt mixture to oil stone.

The mix ratio of pro-asphalt mixture is mainly determined by the following factors:1Asphalt Quality:

Different asphalt quality has different mix ratio of mixture; 2.Aggregate quality: Different aggregate quality has different requirements for the mix ratio of the mixture; 3.

Place of use: Different places have different requirements for the mix ratio of the mixture, such as highways, urban road bureaus, airport runways, etc.; 4.Sieve perforation gradation:

Different gradations of asphalt mixture have different requirements for the mix ratio of the mixture;

5.Mixture use and thickness: Asphalt mixtures of different uses and thicknesses have different requirements for the mix ratio of the mixture.

In general, the mix ratio of asphalt mixture refers to the mix ratio between aggregate, asphalt and ruler group mineral powder (or binder). The above factors need to be considered when determining the mix ratio to ensure the stability, durability and adaptability of the mixture. The specific mixture ratio needs to be designed and adjusted according to the specific engineering requirements.

Pro-rubber 13 asphalt mixture is a common high-elasticity asphalt mixture, and the selection of its oil-stone ratio should be based on the use demand of the road surface, aggregate characteristics, available asphalt types and other factors. In general, the ratio of rubber 13 asphalt mixture to stone is between. The selection of the specific oil-stone ratio should be purely brief and comprehensively considered according to the actual situation, and the mass ratio of asphalt and aggregate is generally required to be 5:

95 ~ 7:93。At the same time, it is also necessary to consider the toughness, strength, durability and other comprehensive properties of the mixture, so as to ensure the performance and service life of the pavement.

In the case of solid trouser crack applications, tests are also required to determine the optimal oil-to-stone ratio to meet specific engineering requirements.