Exploring the Quality Control of Resonance Crushing Construction Techniques

The primary goals of quality control in crushing and screening are the crushing rate and particle size distribution. Generally, it is required to crush 75% of the cement concrete pavement so that the maximum particle size does not exceed 7.5 cm on the surface, 22.5 cm in the middle, and 37.5 cm at the bottom. The particle size after crushing can be controlled by adjusting the height of the hammer drop.

The concrete aggregates should form a dense interlocking structure after crushing, with the aggregates embedding or closely adhering to the subgrade of the old road, eliminating the original gaps of the voided slabs. During crushing, the width of connection with the adjacent lane should be greater than 15 centimeters. The road surface should not be opened to traffic after crushing; if traffic causes the crushed surface to be uneven or damages the bonding layer of the permeable layer oil, it should be compacted again.

The碎石化effect evaluation is not limited to rebound deflection or rebound modulus; it also requires the assessment of the strength variability of the破碎layer for comprehensive identification. The replacement of certain spring plates should be carried out after the old pavement has been破碎ed, and the replacement sections must undergo a rebound deflection test for confirmation.

The settlement after crushing and screening is significantly affected by the condition of the old road, and it is not advisable as a control target for the crushing and screening skill. Close traffic on cement concrete road surfaces after crushing to prevent affecting the uniformity of the crushed layer's strength.

Crushing and粉碎

During and post-construction corrections of fragile substructure or sub-substructure:

Occasionally, individual fragile sub- or sub-sub-levels may be discovered during the破碎 process, and even the aforementioned methods fail to crush them. A similar situation may also arise during compaction operations. In any case, corrections should be made according to the instructions of the supervising engineer.

Remove existing joint filling material:

All loose joint fillers or similar materials should be removed prior to laying the surface layer, and graded crushed stone aggregates should be filled in as required.

Fill in the Dips:

Do not trim or flatten the broken concrete pavement or attempt to improve its linearity, as this will damage the effectiveness of the crushed concrete pavement. Any five-centimeter depressions found before compaction should be filled with dense graded aggregate and compacted to the engineer's satisfaction. The corrected elevation should be smoothed to an equal or better condition than the surrounding concrete pavement. It is important to confirm whether the depression is caused by instability in the subgrade or subbase; if due to fragile foundation, the area will be treated according to the method for fragile foundation.

Compressed requirements after crushing:

Compaction primarily serves to further crush longer and wider particles, consolidating the underlying blocks to add structural strength. Compaction operations should not be conducted under wet conditions to prevent damage to the lower layers. Overcompaction should be avoided, particularly in areas with stability issues.

Firstly, the Z-shaped steel wheel roller uses vibration to compact the surface. The main function of compaction is to further crush the flattened particles on the broken road surface while stabilizing the underlying materials, providing a flat surface for the newly laid water-stabilized material. The compacted surface is treated with the Z-shaped roller for three rounds of vibration compaction, with the roller's compaction speed not exceeding 5km/h.

Secondly, the vibration compaction of the wheel roller. The crushed stone pavement, after being leveled, should be compacted three times with a wheel roller in vibration mode. The roller's compaction speed must not exceed 5,000 kilometers per hour. Overcompaction should be avoided on sections with excessively high or low pavement strength, to prevent the formation of excessively small surface particle sizes or the pressing of the crushed stone layer into the sublayer.

Ultimately, the inspectional compaction of the破碎 concrete pavement. Inspectional compaction involves intentionally applying loads to the fractured concrete pavement and subgrade base material in areas of concern to assess their stability. This is typically done using loaded dual-axle trucks as per engineer's instructions. This process helps identify thin areas that may have been missed during fracturing or compaction, but it should only be conducted before asphalt surface operations, and methods must be used to prevent over-compaction from damaging the fractured subgrade.