A coarse-grained stress-absorbing structural layer asphalt mixture and its design method

Abstract

The invention discloses a coarse grain type stress absorption structure layer asphalt mixture and a design method thereof. The design method comprises the following steps: (1) selecting the type of an asphalt mixture according to engineering requirements; (2) selecting raw materials and carrying out performance detection experiments on the raw materials; (3) determining a reasonable asphalt aggregate ratio range by adopting a large asphalt aggregate ratio; designing gradation of mineral aggregate according to each selected asphalt aggregate ratio; (4) detecting performance of the asphalt mixture; (5) when all performance indexes in step (4) meet requirements, finishing a mixing proportion design; if the performance indexes do not meet the requirements, returning back to design the mixture again until the requirements are met; (6) analyzing results of performance detection and determining optimal asphalt aggregate ratio range and gradation range of the asphalt mixture. The coarse grain type stress absorption structure layer asphalt mixture disclosed by the invention has an effect of a stress absorption structure layer and has various functions of water resistance and cracking resistance, fatigue resistance, prevention and control of reflection cracks and the like.

Description

technical field [0001] The invention relates to the field of road engineering, in particular to a coarse-grained stress-absorbing structural layer asphalt mixture and a design method thereof. Background technique [0002] In recent years, with the continuous improvement of social development and people's living standards, the traffic volume has increased rapidly, and people's requirements for road use have become higher and higher. The pavement base commonly used in the high-grade highways currently built in my country is a semi-rigid base, but the semi-rigid base pavement is prone to reflection cracks under the joint action of temperature and load, which is an important reason for the early failure of the semi-rigid base asphalt pavement one. Another type of situation prone to reflective cracking is the addition of asphalt surfacing over old cement concrete pavements. After a period of use, the cement concrete pavement will be damaged to varying degrees. Adding asphalt co...

AI Technical Summary

Problems solved by technology

However, the common feature of the stress-absorbing layer used at present is that in the pavement structure, the stress-absorbing layer is only used as a simple functional layer, and its function is only to prevent reflective cracks and prevent surface water seepage.

And sand-grain asphalt mixture is often used, which has poor anti-rutting ability and cannot be used as a pavement structural layer.

The paving thickness is generally 2cm to 2.5cm, which is difficult to construct and the anti-crack effect is not ideal

Moreover, various stress-absorbing layers will have various diseases during use, for example, when a conventional stress-absorbing layer is installed, weak interlayers will occur due to factors such as poor construction, etc.

At the same time, engineering practice shows that if the stress absorbing layer is not properly selected or set up, it may accelerate the generation of cracks.

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