1. Make test section to determine construction parameters
1.1 due to the difference of pavement structure and the difference of concrete plate thickness and strength, trial crushing shall be carried out before formal commencement to obtain the best mode and process parameters.
1.2 the general test section is 80-100m. When it is divided into several parameters or mode combinations, the minimum test section length shall not be less than 50m.
1.3 in order to ensure that the pavement is broken into the required particle size, according to the requirements of the on-site engineer, a test pit of about 1.2 square meters is excavated in the carriageway to determine whether the broken block meets the specific size requirements. According to the on-site conditions, the test pit can be added. The excavated test pit needs to be backfilled and compacted to meet the requirements of engineering design. The crushing data meeting the requirements shall be recorded for future reference.
2. Operation construction
2.1 crushing starts from the open edge on one side of the road or from the broken edge in front, and advances to the opposite shoulder or to the longitudinal centerline. When it is necessary to pave one lane at a time, the front crushing width shall exceed the width to be paved by at least 20cm.
2.2 operation mode: according to different road conditions, the combination of hammer heads a, B, C, D and E and two modes of ordinary resonance and pulsating resonance can be used for resonance crushing construction. When the pavement slab is thick and hard, the pre cracking process must be adopted.
3. Quality control
3.1 the quality objectives of the old cement concrete crushing and petrochemical technology are to eliminate the structural diseases of the old cement pavement and subgrade, break and stabilize the cement concrete slab, make the particle size of the broken layer small and well graded, form a high-strength interlocking structure, provide a stable construction platform for the asphalt overlay, effectively reduce or eliminate reflection cracks, and avoid excessive rutting, Improve the service life of the reconstructed pavement.