Asphalt is an important indicator of the quality of asphalt concrete mixtures. Too little, and too much asphalt content would reduce the strength of asphalt concrete, affect the degree of compaction and stabilization; too much will be formed between the mineral aggregate particles free eventually led to road asphalt "bleeding". Is therefore subject to experimental data, development of optimal asphalt-stone ratio and strict controls are in place in the construction of its error within ± 0.3%.

Asphalt: the batch (Pan) products, asphalt-stone ratio is the percentage of weight of asphalt and stone weight values:

Asphalt-stone ratio = weight/asphalt (aggregate + powder + powdered admixtures) • 100%.

4.1 factors affecting asphalt

Aside effect of temperature and additives and artificial factors, the main factors are: aggregate, powder, asphalt three metering control static and dynamic dynamic measurement accuracy of measurement.

4.1.1 the factors affecting aggregate weighing accuracy

(1) the hopper container: container size and weight (level) weighing impulse;

(2) door size: large, impulse; small, weighing time again;

(3) the cylinder (exhaust valves) speed: fast shutdown will reduce impulse;

(4) automatic impulse performance: better regulation and automatic control system of compensation is also key.

4.1.2 factors influencing the powder weighing accuracy

(1) stability of powder: powder material source or material can guarantee the stability measurement for powder;

(2) screw feed speed: slow long weighing time cycle; increasing the weighing element; after the calculation or application can adjust (also useful for variable frequency speed regulation);

(3) export butterfly valve configuration and the action (containing sealed sex): usually powder material measurement with spiral conveying device (also useful impeller to material machine), dang computer judge said enough stop Shi, due to inertia role, its more turned number depends on at spiral within powder material volume, is a not constant of impulse value; so to with with brake of deceleration machine, but most with export added loaded sealed sex good of fast shut broken butterfly valve to limit impulse, to guarantee said powder precise;

(4) the said powder weight compensation: recycled content is small, under the same error kg, precision collection itself is difficult to ensure; but if the amount of the new "after the large amount of said total compensation", ensure the powder weight constant, better results can be achieved;

(5) the automatic impulse performance: better regulation and automatic control system of compensation is also key.

4.1.3 the factors affecting pitch weighing accuracy

(1) recycling asphalt supply stability: is single-pipe or two-pipe stairs, three-way valve in the upstairs or downstairs for asphalt supply affect asphalt temperature (modified asphalt requires a sufficiently high temperature fluidity is good);

(2) three-way valve cylinder weighing speed (with three-way valve seal): fast shutdown action can be used to reduce the cylinder weighing impulse;

(3) discharge way: guarantee the required pitch effectively into the mixing cylinder;

(4) automatic impulse performance: better regulation and automatic control system of compensation is also important.

4.2 improving aggregate, asphalt weighing precision of powder, the main measures

(1) high precision sensor, amplifier or instrumentation, and has better resistance to interference and vibration capability while mixing stability, pressure relief pipes flowing, signal shielding and grounding, materials are relatively modest and symmetric shock and so helps to improve the accuracy of dynamic weighing;

(2) the scales of measurement often used standard weight check calibration and adjustments in a timely manner;

(3) skilled and effective adjustment: familiar with the performance of product components, the correct parameters (, thick set, impulse time parameter compensation parameter set) settings, skilled and effective adjustments can reduce human error;

(4) choose the quick shutoff pneumatic cylinder, solenoid valve, butterfly valve, reducing flying and impulse;

(5) the total aggregate compensation, after a large quantity of powder is known as total compensation, asphalt-stone ratio automatic tracking: these are specific and effective way;

(6) the automatic program stability, good performance: high quality components, reliable and stable, adequate compensation methods and measures is on asphalt-stone ratio accuracy guarantee.