Vibration molding-based method for design of mix proportion of graded broken stones

Abstract

The invention relates to a vibration molding-based method for design of mix proportion of graded broken stones, comprising the following steps: (1) selecting raw materials: selecting limestone as the base stone of the graded broken stones, adopting a reaction crusher to roll till the technical requirements are met; and selecting drinking water as added water for the mixture of the graded broken stones; (2) preparing optimized graded broken stones; (3) adding the drinking water into the graded broken stones in the step (2) according to 4-5% of water content to prepare a plurality of groups of mixtures of the graded broken stones; (4) carrying out vibrating compaction on the groups of mixtures of the graded broken stones obtained in the step (3), and determining the optimum water content and maximum dry density of the mixture of the graded broken stones under a vibrating compaction test mode; and (5) verifying the performances: under the conditions of the optimum water content and the maximum dry density determined by the step (4) and 98% of compaction degree, adopting a vibration molding test method to determine the California bearing ratio (CBR) of a test piece. The mixtures of the graded broken stones designed by adopting the method have the characteristics that the strength is high, the total quality is high, the construction is simple and convenient and the cost is low.

Description

technical field [0001] The invention belongs to the technical field of road engineering, in particular to a mixing ratio design method based on vibration forming and grading gravel. Background technique [0002] As the most important structural form of high-grade highway pavement, semi-rigid pavement has played an important role in the construction of expressways in our country. The semi-rigid base asphalt pavement structure, material design methods and construction technical specifications are becoming more and more perfect. However, some inherent shortcomings and deficiencies of the semi-rigid base asphalt pavement in the process of use have led to large-scale early failure of expressways in our country. In particular, newly-built expressways generally fail to meet the design period required by pavement design. A large number of applications and studies have shown that the diseases caused by semi-rigid base factors mainly include: ① reflective cracks on the road surface;...

AI Technical Summary

Problems solved by technology

③Semi-rigid pavement is prone to early fatigue damage under heavy load and overload

[0005] Compared with the above several measures to reduce cracks in semi-rigid pavement, the first method cannot fundamentally eliminate the cracking of semi-rigid base material

The second method is economically uneconomical

The third method, soft asphalt concrete is only effective in preventing and reducing reflective cracks in cold weather, and the cost is high, and the drainage effect is not good, while the middle layer of geotextile and stress-absorbing membrane is very thin, and the drainage effect is not good

The fourth method is not effective in preventing reflective cracks and drainage

However, the stiffness and strength of the graded gravel base are lower than those of the semi-rigid base, and at the same time, the road surface deflection is relatively large, causing researchers and designers to worry that the bearing capacity of the graded gravel is not enough, which limits the use of graded gravel in my country. Application in highway

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