Method for preparing road base material cylindrical test piece simulating on-site rolling effect

Abstract

The invention discloses a method for preparing a road (bottom) base material cylindrical test piece simulating on-site rolling effect. The vibration compaction test method is adopted to determine the maximum dry density rhodmax and the optimal moisture content wo and the vibration method is adopted to prepare the cylindrical test piece. The operation process of the method corresponds to the on-site practical construction process. The maximum dry density and the optimal moisture content of the tested (bottom) base material and the prepared test piece coincide with the on-site practical rolling effect. The test result of the performance of the test piece is objective and real; and the method has good repeatability. Steps of measuring the moisture content of dried aggregates and moisture content of dried test samples, a step of interlayer broom-finish treatment, a step of flattening the surface of the samples and the like are saved; the material feeding process is simplified; and the working efficiency is improved. The method has the advantages of simple operation, reliable result and good repeatability.

Description

technical field [0001] The invention belongs to the field of traffic civil engineering, and relates to a method for preparing a cylindrical specimen of a road (bottom) base material for simulating on-site rolling effects. The method is simple and quick to operate, and the performance test results of the prepared test piece objectively and truly reflect the actual performance of the (sub)base material, and the reproducibility is good. Background technique [0002] At present, the compaction test method is used to determine the maximum dry density ρ of highway (sub) base material dmax and the optimum water content w o , according to the ρ of the compaction test method dmax and w o The principle and steps of preparing a cylindrical specimen of highway (bottom) base material by static compaction are as follows: [0003] (1) Determine the ρ of the road (bottom) base material by the compaction method dmax and w o , the experimental steps are: [0004] ① One day before the s...

AI Technical Summary

Problems solved by technology

[0023] ④ The compaction test is divided into three layers of samples for compaction, which is inconsistent with the actual on-site production process, and the simulated construction effect is poor;

[0024] ⑤ Layered material loading and layered compaction thickness, roughening treatment after compaction, and sample surface leveling treatment after compaction will affect the compaction effect due to different testers, and the test reproducibility is poor;

[0025] ⑥The air-dried moisture content of the aggregate is measured during the material preparation process, the sample is divided into three layers into the compaction cylinder and compacted 98 times in each layer, and the process of drying for 8-12 hours to measure the water content is complicated and time-consuming.

[0027] ① The compaction method does not match the static compaction preparation method;

[0028] ② The test piece prepared by static compaction method does not meet the conditions of the actual vibratory rolling forming (bottom) base layer, and the composition structure of the prepared test piece does not match the actual rolling forming (bottom) base layer structure;

[0029] ③The crushing of the coarse aggregate during the preparation of the test piece is more serious, and the gradation of the prepared test piece does not match the gradation of the actual (sub)base layer formed by rolling;

[0030] ④The loss of water content in the preparation process of the specimen is relatively serious, and the loss of water content leads to a decrease in the actual cement dosage of the specimen, which is inconsistent with the water content and cement dosage of the (bottom) base layer formed by actual rolling on site

[0031] To sum up, the compaction test method is quite different from the actual production due to the compaction method, compaction work and specific operation method, resulting in a relatively small maximum dry density and a relatively large optimum water content; The medium structure, gradation, water content, cement dosage, compactness, etc. are not consistent with the actual rolling base, the prepared specimens are not representative and authentic, and the physical and mechanical properties of the test cannot truly represent the actual performance of the base

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