Vibration-molding-based cement stabilized macadam mixing ratio design method

Abstract

The invention relates to a vibration-molding-based cement stabilized macadam mixing ratio design method, which comprises the following steps: (1) preparing optimized dense skeleton type graded aggregate; (2) adding cement into the graded aggregate to prepare cement stabilized macadam mixture; (3) vibrating and compacting the cement stabilized macadam mixture, and determining the optimal water content and the maximum dry density of the cement stabilized macadam mixture in mode of a vibration and compaction test; (4), preparing cement stabilized macadam cylindrical test pieces by using a vibration molding test process at a compactness of 98 percent under the determined maximum dry density and the optimal water content; and (5) perform an unconfined compression test on the prepared cement stabilized macadam cylindrical test pieces and determining the dose of the cement according to the result of the unconfined compression test. The cement stabilized macadam mixture designed by the invention has the characteristics of high strength, high crack resistance, convenience for construction and low cost, and an innovation is made in semi-rigid material design on the basis of a material design guiding ideology.

Description

technical field [0001] The invention belongs to the technical field of road engineering, in particular to a method for designing the mixing ratio of cement-stabilized gravel based on vibration forming. Background technique [0002] The vast majority of expressways in my country adopt the semi-rigid base asphalt pavement structure. On the one hand, the early failure phenomenon of the built semi-rigid pavement represented by cement gravel is relatively serious; Rigid pavement is still growing with thousands of kilometers of construction mileage per year. From the perspective of application effects, the research results based on traditional material design methods are not obvious for alleviating or eliminating the early failure phenomenon of semi-rigid pavement (a more consistent view is that semi-rigid base cracks are inevitable), which leads many domestic highway workers to Doubts arise whether the semi-rigid pavement structure is suitable for China's national conditions. ...

AI Technical Summary

Problems solved by technology

[0004] ①The indoor molding method does not match the on-site rolling method

As a result, the indoor test results are difficult to guide on-site production, and even seriously affect the quality of the project

[0006] ②Single quality control index

However, if the indoor forming conditions are not changed, and the heavy compaction method is still used, it can only lead to the construction of semi-rigid bases that are almost the same as before with today's road construction machinery. What is more serious is that indoor test standards have seriously hindered technological progress and The development of production makes the contractor less motivated to use new technology and new equipment

[0010] ④The grading range stipulated in the code is too wide to ensure the quality of the project

Within this range, the mechanical properties of different graded mixtures are very different. Therefore, even if the various mechanical indicators of cement and gravel mixtures with different grades meet the requirements of the specification, it is difficult to say that the mixture that meets the requirements of the specification gradation has good crack resistance

[0012] As mentioned above, the early failure of cement-stabilized gravel mixture is closely related to the unreasonable indoor molding method and single standard, which lead to excessive cement dosage, low compaction standard, and poor gradation.

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