For the 10-Year Anniversary of AsphaltPro magazine, we will help asphalt companies teach new workers some back-to-basics techniques for best success in the field, at the plant and in the lab. Even veteran employees will be reminded of best practices with these refreshers throughout the year, but the goal is to help readers who are bringing in new employees who may or may not be well-versed in the industry yet. On-the-job training takes time and energy, and we’re here to help with the Asphalt Paving 101 online training course and these free articles every month.
Many commercial paving crews don’t have one designated broom operator, but will assign the task to the laborer who is closest to the machine when an area needs to be cleaned or when the mill has completed a pass. No matter what size the job or who will be at the controls for the day, the broom cleaning the pavement can save you time and money if an operator is responsible for keeping it in good repair. John Ball, the proprietor of Top Quality Paving and Training, Manchester, New Hampshire, explained that is because a well-maintained broom with a full broom head will need fewer passes to do its job than a broom with worn bristles or a damaged water system, etc. The well-maintained broom is also a safer piece of equipment for the operator and less likely to break down during operation. Now that the Occupational Safety and Health Administration (OSHA) has stipulated requirements for minimizing workers’ exposure to respirable crystalline silica dust, water system operation on brooms will be a vital inspection point.
Ball reminded workers to start routine maintenance with the pre-shift walk-around. The person assigned to run the broom needs to walk around the machine to do the following:
- Check the oil
- Check the fuel
- Check the tires for proper air pressure (probably should be 32 pounds)
- Check the lights—make sure all lights are functioning, including 4-way flashers and a strobe
- Check the windows and clean them
- Check the mirrors and clean them
- Check the fire extinguisher
- Clean out the cab—get trash out of the cab so it’s not underfoot
- Grease the grease fittings for the articulation
Give special attention to the water system:
- Check the spray system’s water tips and the filters in the water tanks to ensure they are clean
- Check the lines for wear or cracks
- Check the reservoir to ensure its filter is clean to allow a clear flow of water to the lines and nozzles
- Make sure you have a water cap on the tank—if you have lost this, order a new one
- Remember, your crew can get fined for making too much dust during the sweeping stage of your project, and your health is dependent on reduced dust, so you must have a functioning water system.
Before the shift begins, the operator should look at the thickness of the bristles and broom core. This is a visual inspection, not something you will measure with a ruler. (Another way you’ll know if the core has started to wear is when it “hops” during sweeping or fails to rotate in a consistent manner.)
Let the mechanic know four or five days in advance of when you think the core will need to be replaced so he has time to order the new parts. If you don’t have a fulltime mechanic, then you—the operator—should take the responsibility of getting the part ordered.
Bristles come in both plastic and metal core; these days the core that alternates plastic and metal are preferred because they don’t wear out as quickly as the plastic-only cores. It only takes about an hour and a half to change out a core, according to Ball. And the process is self-explanatory. The core is circular. When you remove it, you’ll see the keyseat—like a cog in the yoke—where the core will slide in and lock.
Notice in these pictures that the core/broom head on the piece of equipment moves down the lane at an angle. The articulation that allows this angle has grease fittings that you’ll want to check everyday and grease before operating the machine. Not only can those fittings get dusty and dirty, if you forget to grease them, they will seize up. If the machine breaks so that it’s in one fixed position, the core won’t articulate left and right, and you won’t be able to do your job efficiently.
Also notice the hydraulic pump. On the other end is a bearing that you’ll want to grease before operation. Both ends of the drum need to be checked before operation as well. They both need to be free and clear of debris—debris is more than dust and millings. Keep in mind this machine can grab stringline, plastic bags and all manner of trash that blows around a commercial parking lot, residential area or state road. Those items will damage the ends and cause the broom to seize.
When checking the watering system, make sure to clean the nozzles—and their filters—so they are clear and free of dirt and dust. The filter is 10,000 microns and that level of mesh gives you the correct pressure. You want a fine mist to cover the broom during operation, not squirts and spurts of water that cause dirt to cake up on the bristles or leak onto a pavement your team needs to then tack or seal.
By taking the time to maintain the broom properly, you save time during the pavement cleaning process.
When you’re ready to begin sweeping for a pavement maintenance project, you will obviously get started ahead of the tack wagon, crack-filling workers or sealer machine. You want to get all the dirt and leaves off the surface before any other equipment begins. You will line up the machine at the edge of the project or area to be cleaned, taking care to keep the broom’s bristles from catching dirt or grass from landscaping or features at the edge of the property. You don’t want to pull detritus onto the project. It’s best to set the broom 2 to 5 inches from the edge when working along a pavement that has no raised curb to enclose the work space.
For a parking lot or roadway with minimal dirt and debris, you will want to adjust the broom height so that the bristles just barely brush the surface. The spinning motion will pull leaves and litter off the surface; you don’t want to dig at them with too much down-pressure. Set the broom at a 33-degree angle for the first pass and drive at a moderate speed; Ball recommends a reasonable walking pace.
When you’re ready to begin sweeping a surface behind the milling machine, you will use more down-pressure to get particles out of the crevices. The goal is to prepare a clean, dust-free pavement for the distributor truck to place tack on. You will want to adjust the broom height so that the bristles have more down-pressure. You don’t want to hinder the rotation of the broom, but you want to dig out the particles—thus it’s a judgment call that comes with practice and experience. Ball reminded new broom operators: if you put too much down-pressure on it, the broom will start to “plow” instead of sweep, damaging the bristles and possibly the core.
Once again, set the broom at a 33-degree angle and drive at a speed that’s acceptable for this operation. You can start with 35 to 50 feet per minute and adjust from there. For this type of operation, the skid steer operator will come alongside and scoop up the pile/trough of material, and the broom may be required to make a second pass if a second broom isn’t on the job following behind.
For sweeping during construction, pay attention to water use and drying. Excess water will dilute your tack and weaken its bond to the surface. You may need a machine that can sweep and vacuum. The broom operator should be aware of the paving plan; make sure you know what the foreman needs from you before you get started.
Let’s say you’re going to work on a porous pavement. There are sweeping subcontractors who don’t recommend using a broom-only when cleaning a porous pavement. If you feel that the bristles of your broom will lodge fine particles—instead of dislodging them—in a gap-graded surface course, you’ll want to employ a vacuum as well to suck fines and material up.
The vac broom has three broom attachments to help you—on the sides and center. The side brooms dislodge material from the surface and funnel it toward the center for the vacuum to pull it up.
Employers Can Get Silica Help
If you’re a contractor in need of answers, you can ask questions without fear of penalty. The Occupational Safety and Health Administration (OSHA) has on-site consultation services that are separate from enforcement. From the OSHA silica-crystalline website: “Small business employers may contact OSHA’s free and confidential On-Site Consultation program to help determine whether there are hazards at their worksites and work with OSHA on correcting any identified hazards. Consultants in this program from state agencies or universities work with employers to identify workplace hazards, provide advice on compliance with OSHA standards, and assist in establishing injury and illness prevention programs. On-Site Consultation services are separate from enforcement activities and do not result in penalties or citations.”
To contact the service, visit here or call (800) 321-6742, option 4.
Meet Silica Requirement
As of June 2017, employers are required to take steps to protect employees from the hazards associated with exposure to respirable crystalline silica. In the Occupational Safety and Health Administration’s (OSHA) Respirable Crystalline Silica standard for Construction, the administration compiled a table that listed standards for different pieces of equipment that expose a worker to different levels of this dust. The broom is one such piece of equipment.
If your broom has an enclosed cab, the employer must ensure that the enclosed cab or booth is:
- Maintained as free as practicable from settled dust;
- Has door seals and closing mechanisms that work properly;
- Has gaskets and seals that are in good condition and work properly;
- Is under positive pressure maintained through continuous delivery of filtered air;
- Has intake air that is filtered through a pre-filter that is 95 percent efficient in the 0.3-10.0 microgram range; and
- Has heating and cooling capabilities.
The controls for enclosed cabs lower the potential for dust to be re-suspended inside the cab or enter the enclosed cab or booth. They also ensure that the filtered air provided to the employee does not contain silica particles and that the working conditions in the cab are comfortable so that employees are less likely to open windows and be exposed. The procedures for maintaining and cleaning the cab or booth, and for frequent and regular inspections of the cabs and booths, must be addressed through the employer’s Written Exposure Control Plan and Competent Person requirements.