A wet mix macadam plant blends graded aggregate with the right amount of water for the road base. A feeder off calibration changes the gradation, worn pugmill paddles leave the mix patchy, and a faulty water meter pushes moisture off target. Any of these can mean rejected layers and lost days on a highway package. Daily checks and regular calibration keep output steady. This checklist covers them, and shows how contractors keep every WMM plant inspection on record in HVI.
WMM Plant Inspection Checklist: Wet Mix Macadam Plant Guide
Feeder bins and belts, pugmill paddles and liners, conveyors, water dosing and calibration, gearboxes, motors and electrical panels.
Daily Start-Up Checklist
Complete these before the first load each day. Do not start if any safety item fails.
Component Inspection Guide
Inspect these regularly alongside the daily check. Follow the plant maker's manual for limits and service intervals.
| Component | What to inspect | Warning signs |
|---|---|---|
| Feeder bins | Gates, vibrators and bin walls | Material bridging, gates sticking |
| Feeder belts | Belt, rollers and speed control | Slipping, worn belt, speed drifting |
| Pugmill | Paddles, tips, liners and shafts | Worn paddles, patchy mix, noise |
| Water dosing | Pump, meter, valves and spray bar | Uneven moisture, blocked nozzles |
| Conveyors | Belts, idlers, scrapers and splices | Spillage, torn belt, seized idlers |
| Gearboxes and motors | Oil, temperature, vibration and mountings | Overheating, leaks, unusual noise |
| Electrical panels | Contactors, cables and earthing | Tripping, burnt contacts, loose cables |
Calibration for Consistent Mix
Calibrate at the start of a project, after repairs and whenever lab results drift from the design.
Feeders
Check each feeder's output against its setting.
Water meter
Confirm the meter reads the actual flow.
Trial mix
Test gradation and moisture in the lab.
Record
Keep calibration results for audits.
Every Plant Check and Calibration on Record
HVI gives plant operators a daily checklist on their phone, records calibrations and defects with photos and keeps a full history for each WMM plant.
Looking After the Pugmill
The pugmill does the mixing. Its wear parts decide how even the mix is.
Paddles and tips
Replace when worn so the mix stays even.
Liners
Protect the trough and keep clearances right.
Shafts and bearings
Grease as specified and watch temperature.
Daily cleaning
Remove build-up before it hardens.
Never reach into the pugmill, feeder or conveyor while the plant can start. Isolate the power, fit your personal lock and tag, and test that nothing can move before cleaning, changing paddles or clearing a blockage.
WMM Plant Status in HVI
A sample view across a contractor's plants, showing the daily check, last calibration and open defects.
| Plant | Project | Daily check | Last calibration | Status |
|---|---|---|---|---|
| WMM-01 | Highway package 1 | Passed | 12 days ago | Producing |
| WMM-02 | Highway package 3 | Passed, paddles worn | 30 days ago | Plan paddle change |
| WMM-03 | Bypass project | Failed, conveyor guard missing | 8 days ago | Do not start |
WMM Plant Inspection FAQs
What should be checked on a WMM plant every day?
Feeder bins and belts, the pugmill and its paddles, the water tank, pump and meter, gearbox oil levels, guards, emergency stops and the control panel, all before the first load.
How often should a WMM plant be calibrated?
Calibrate at the start of each project, after any repair to feeders or the water system, and whenever lab tests show gradation or moisture drifting from the mix design.
Why does WMM come out patchy or uneven?
Common causes are worn pugmill paddles, blocked water nozzles, feeders out of calibration or material bridging in the bins. Check these in order to find the cause.
How do I keep the pugmill working well?
Clean it daily, replace worn paddles and tips, check liners and grease shafts as specified. Teams that log pugmill checks in HVI can plan paddle changes before quality slips.
Can WMM plant checks be done on a phone?
Yes. Operators complete the daily checklist with photos and record calibrations, and supervisors see every plant's status. Book a demo to see WMM plant checklists in HVI.
Steady Output, Consistent Base Layers
Run daily WMM plant checks, calibrate on schedule and track every defect and repair in HVI. Fewer stoppages, less rework and base layers that pass first time.
