Common questions from road construction buyers, fleet managers, and procurement teams — answered by the engineers who design and test our equipment.
For a standard hot-mix asphalt overlay, a three-stage rolling train is recommended: breakdown rolling (double drum vibratory, 8–14 t, immediately behind the paver while mix temperature ≥ 140°C), intermediate rolling (pneumatic tire roller, 16–24 t, to achieve density uniformity and surface sealing), and finish rolling (double drum roller in static mode to eliminate any tyre marks).
The breakdown roller must operate within 15–30 m of the paver screed to capture compaction while the mix is still at working temperature. Waiting until the mat cools below 120°C significantly reduces achievable density.
Vibratory rollers use eccentric mass rotation to generate impact compaction force (80–130 kN on standard units) — effective for granular materials (sub-base, base course) and the initial breakdown passes on asphalt. They compact from the bottom up.
Pneumatic tire rollers use kneading action through multiple overlapping rubber tyres — they compact from the top down and produce superior density uniformity and surface sealing on asphalt. They are the preferred choice for final passes on wearing courses, particularly on high-speed highways and airport pavements where surface texture and void content are critical.
Most pavement construction projects use both types in sequence. If budget allows only one roller, the double drum vibratory is more versatile across different materials.
For a 3.75 m lane, a 1.5 m or 2.0 m drum width roller is typical. A 2.0 m drum will cover the lane in two passes with 25 cm overlap — maximizing production rate. A 1.5 m drum requires 3 passes. Wider drums improve production but reduce maneuverability near curbs and drainage structures.
Edge compaction within 150 mm of the lane edge requires a smaller tandem roller (drum width 600–1,000 mm) or plate compactor if the main roller cannot compact flush to the edge without risk of rutting.
Compaction force is the centrifugal force generated by the eccentric mass rotating inside the vibratory drum, measured in kilonewtons (kN). It is the primary factor determining how deep the compaction energy penetrates into the material layer. Higher compaction force = deeper compaction influence depth.
For reference: a 10 t double drum roller generates approximately 100–130 kN at high amplitude — suitable for compacting 80–150 mm asphalt layers. A heavy single drum roller at 25 t can generate 250–350 kN — needed for deep-lift granular compaction up to 500 mm in one pass.
Amplitude (eccentric mass offset) also affects compaction force. Most Bomag rollers offer two-amplitude selection (high/low) for different layer thicknesses. Use high amplitude for thick layers and lower amplitude for thin asphalt overlays to avoid cracking the aggregate.
Yes. All Bomag road construction equipment carries CE marking under EU Machinery Directive 2006/42/EC. All models with engines above 19 kW meet EPA Tier 4 Final (USA/Canada) and EU Stage V (Regulation 2016/1628) emission standards. Our engine OEM partners (Cummins, Perkins, Yanmar) provide individual engine compliance certificates that are included in each machine's documentation package.
ISO 9001:2015 factory certification is maintained through annual Bureau Veritas surveillance audits. Copies of CE declarations of conformity, engine emission certificates, and ISO certificates are available on request before order placement.
Standard production lead time is 8–12 weeks from confirmed order and receipt of deposit (typically 30%). Expedited 6–8 week delivery is available for select models from our pre-production inventory program — confirm at time of inquiry.
Port of loading is Tianjin or Guangzhou. We can arrange ocean freight on FOB, CFR, or CIF terms. Export documentation (HS code classification, packing list, commercial invoice, bill of lading, CE declaration) is prepared by our export team and provided in full for customs clearance.
Yes. All Bomag road equipment ships with a 12-month / 2,000-hour standard warranty. Extended 36-month / 5,000-hour warranty is available for fleet orders of 5+ units.
Spare parts are stocked in regional logistics hubs for 48-hour delivery to most destinations. Major wear items — drum scraper bars, water spray nozzles, drive belts, hydraulic hose assemblies, and vibration bearing kits — are maintained in stock for all models in production. An online parts ordering portal and spare parts catalogue are provided to all customers at delivery.