I have summarized the most practical on-site key points to directly prevent shoving and cracking, which can be used for both exams and construction – all practical essentials.

I. Key Points to Prevent Shoving (Bulging, Waviness)

Temperature Control (Most Critical)

• Initial rolling must be carried out at high temperature.

• General rule: Start initial rolling at not less than 130℃.

• Low temperature → mixture becomes hard → shoving will definitely occur.

Static Pressure for Initial Rolling, No Vibration

• Use static pressure with a tandem-drum roller to stabilize the mixture first.

• Starting vibration immediately after paving → definite shoving and bulging.

Rolling Direction and Speed

• Roll from the lower side to the higher side, from the road edge to the center.

• Keep speed slow, stable, and uniform.

• No sudden starting or sudden braking.

Coordination Between Paver and Roller

• Follow closely behind the paver, roll in short distances and continuously.

• Do not wait until the mixture cools down before rolling.

II. Key Points to Prevent Cracking

Strictly Forbid Rolling at Low Temperature

• Forcible rolling at excessively low temperature → direct transverse and map cracking.

• Final rolling finishing temperature: generally not less than 70℃–90℃ (depending on the mixture).

Correct Timing for Vibration

• High temperature: vibration can be used.

• Low temperature: vibration must be turned off.

Reasonable Number of Rolling Passes

• More passes are not always better.

• Over-rolling → asphalt bleeding, aggregate crushing → cracking.

Joint Treatment

• Lightly roll transverse and longitudinal joints first, then roll normally.

• Avoid sudden stops and sharp turns at joints.

III. One-Sentence Summary (Easy to Remember)

Follow closely with static pressure at high temperature for stabilization;Vibrate and knead during secondary rolling without over-compaction;Turn off vibration at low temperature to prevent cracking.