Grinding forming method and device for simulating construction state of bituminous mixture standard sample

Abstract

The invention belongs to the technical field of simulating the working condition of the grinding construction forming of a bituminous pavement and specifically relates to a grinding forming method and device for simulating a construction state of a bituminous mixture standard sample. The grinding forming device for simulating the construction state of the bituminous mixture standard sample is characterized by comprising a mold plate, a grinding wheel, a grinding wheel pressure control device, a grinding wheel times control device, a mechanical driving control device and a detection device, wherein the grinding wheel is used for grinding a bituminous mixture; the grinding wheel pressure control device is used for supplying the pressure under the grinding wheel; the grinding wheel times control device is used for calculating the reciprocating times of the grinding wheel; the mechanical driving control device comprises a vibrating plate and a motor; the vibrating plate is arranged under the mold plate; and the motor is used for supplying the up-and-down vibrating power of the vibrating plate. The device can extremely simulate the grinding and kneading effects suffered by the mixture in the grinding and forming stage of the pavement, and can manufacture bituminous mixture standard samples meeting industry standards and local standards.

Description

technical field [0001] The invention belongs to the technical field of simulating the rolling and forming working conditions of asphalt pavement, in particular to a method and equipment for simulating the rolling and forming of asphalt mixture standard test pieces in the construction state. Background technique [0002] With the rapid development of my country's economy, major changes have taken place in the composition of high-grade highway traffic in recent years. Large-flow, heavy-axle-load traffic has become the main transportation mode of expressways, and has also become a key factor controlling the design of pavement structure and materials. Here The early failure phenomenon of asphalt pavement in the environment is very serious. The investigation shows that the early failure phenomenon of asphalt pavement in my country's high-grade highways is mainly rutting, oil flooding, loosening and water damage. Related research shows that as far as the mixture itself is concerned,...

AI Technical Summary

Problems solved by technology

[0003] (1) Rutting: The common problem of asphalt pavement with early rutting damage is that the amount of asphalt is too large and the density of the mixture is low

[0008] ⑴The indoor molding method does not match the on-site rolling method

A series of questions are derived from this: whether Marshall compaction density is suitable as the control index of on-site compaction; the mechanical properties of the mixture may be different under the action of compaction and kneading respectively, so what kind of molding method is used to make the test piece, Its indicators are more effective in controlling on-site quality; whether the mix ratio (including gradation, asphalt-stone ratio, density, etc.) optimized by indoor research using Marshall method is optimal in road performance under on-site compaction conditions

However, in terms of specimen forming, there is no intrinsic connection between the number of Marshall method hammering and the compaction function during pavement forming. There is a huge difference between the impact force of Marshall hammer and the ground pressure of vehicle wheels, and the constraints of Marshall test mold on asphalt mixture are also different. Different from the stress conditions of actual pavement materials, Marshall’s impact compaction method is not conducive to the directional rearrangement of aggregates, so there are hidden dangers in the quality control of various indicators of test pieces formed by Marshall’s compaction method

[0011] ⑵ It is difficult to realize the design intention and coordinate various contradictions with the volume parameter as the control index

However, research results at home and abroad have shown that there is a large gap between these indicators and road performance indicators.

[0021] (1) The method of Marshall compaction forming the test piece does not match the road construction rolling conditions, and the density of the mixture test piece is low

[0022] ⑵ It is unreasonable to use VMA, VFA, VV and other volume parameters as control indicators, which often makes the amount of asphalt too high, and is prone to oil flooding, rutting and other diseases under heavy traffic conditions

[0032] ⑴ SUPERPAVE does not have perfect theoretical and empirical basis for the regulation of “control point” and “forbidden zone” of the gradation curve. The gradation within the specified range of gradation must have poor road performance

[0035] (4) Although the design porosity (4%) and the minimum mineral material porosity of the test piece are strictly regulated, the influence of the accuracy or reliability of the basic test on the porosity is not considered, and the method of determining the theoretical maximum density is unreasonable , making the calculated volume parameters of the specimen unreliable

[0038] But this equipment is an imported product, the cost is very high, the mechanical structure is quite complicated, and the maintenance is inconvenient, so it is difficult to promote and use it at present

Images