Hamm asphalt rollers

Types of asphalt roller

The asphalt roller is a key piece of equipment for pavement construction and the core tool for road maintenance. There are three main types of asphalt rollers: the static roller, the pneumatic rubber tire roller, and the vibration roller.

• Static asphalt roller: Usually large steel cylinders, the static rollers rely on their weight and static pressure to compact asphalt. They are suitable for preliminary compaction of asphalt mixtures, road base, and soil. Because of their low price and simple maintenance, static rollers are suitable for less demanding secondary roads, rural roads, and non-asphalt materials.
• Pneumatic rubber tire hamers: These compact asphalt mixtures through pressure and kneading. The tires can provide better shear strength and adapt to various working conditions. In addition to compacting asphalt mixtures, they are also ideal for compacting gravel and lime soil. Their versatility and good adaptability make them suitable for primary and secondary road pavement projects and urban road construction.
• Vibratory asphalt roller: Also known as vibratory rollers, these HAMM asphalt rollers are equipped with vibrating steel drums that provide dynamic force, which increases the compacting efficiency. The vibrating function enables uniform compaction of the asphalt mixture. They are suitable for high-demand primary road construction projects such as highways and the main streets in urban areas. Their high performance also makes them suitable for the construction of airportrunways.

Specification and maintenance of hamm asphalt rollers

For a safe and effective application, it is crucial to get to know the specific features of the roller.

• Driving forces : The driving forces can be hydraulic, diesel engine, fully hydraulic, or chain and shaft driving.
• The loads: The load includes self-weight and supplemental weight, the supplemental weight comes in the form of steel or lead weights, and the former is the more common choice. The self-weight of a roller can vary from 8,000-11,000 kg for tandem rollers and 3,000-9,000 kg for lightweight rollers, while the supplemental weight may range from 3,000-5,000 kg, bringing the total weight to 12,000 kg-14,000 kg.
• Drum: For smooth finish surfaces and adequate ballast material, the drums are chrome-plated and polished in a dual-cylinder design. The diameter for smooth wheels ranges from 1000- 1300 mm and up to 1300-1800 for a sheep's foot or padfoot design, with corresponding widths of 1700-2200 mm and 1850-2400 mm. The drum design varies to obtain a different level of compaction. The smooth roller compacts the airspace in the granular material and bottom layer, while the corrugated roller leaves pockets that fill with water when used in the agricultural industry. The 'sheep foot' or 'padfoot' design provides greater uniform penetration and compaction.
• Vibration frequency:The frequency of vibration varies according to the underlying layers that need to be compacted. For granular soils, the frequency is 3- 4 Hz, and for asphalt, it is 4-5 Hz. Each drum has its own frequency of drums and amplitude of oscillation, which directly impact the density attained and support required.
• Travel speed: The travel speed differs according to whether it's an isolated task, a part of a complete project, or the type of soil being worked on. It may range from 6-8 km/h on granular and cement-stabilized bases, 4-5 on lateritic rocks and lime-stabilized soil, 5-6 on sub-base layer gravel, 0.5-1.3 km/h on the bottom layer soil. The speed is lower when working on clayey soils and depends on the need to work beneath the surface.

Roller maintenance:

• Daily maintenance: See to it that all fastenings, brakes, lights, transmissions, engine fuel, and tire pressures, etc., are checked and anything that needs to be lubricated is attended to, including chains, pins, and, importantly, the drum bearings to get protected against environmental erosion. Make sure to check for any loose or damaged parts of the rollers, including cracks or frame damage, which can happen due to transport over long distances or because of incorrect use. If any skin or tire damage is found, investigate the root causes and repair them.
• Weekly maintenance: On the week of use, clean out any oil, grease, or dirt to remove rust, including lubricating all articulation points and chains to keep visual sight clearance.
• Experiment: Maintenance will take less time if the equipment is used expertly and trained personnel are familiar with its machinery. For parts that warrant lubrication, greasing once a week is enough unless specified otherwise. The same goes for daily maintenance of overhead chains, sheaves, hydraulic hoses, etc. Seals need to be examined more frequently if they are working under more than 30 hours of continuous use.

Scenarios of asphalt roller

These are some of the common applications of rollers for pavement of asphalt.

• Pavement asphalt: This method of rolling is evenly performed across the entire surface area of the asphalt layer. Here, the seams should be overlapped and be about 1/2 to 3/4 of the width of the roller. The rolling can be done in a circular pattern. When using a breakdown roller, rolling should begin at the side of the curb and move back and forth toward the center with three or four passes.
• Pavement joints: For this method, the roller should run the entire length of the joint with three or four passes.
• Curb areas: For this method, curbing stones should be rolled using a 3-wheeled roller without the need to remove the shoulder forms.
• Shoulder areas: For this method, the lateral slope of the pavement should be rolled with the roller having the slope of the shoulder. When the road has a 2:1 slope, the roller should be about 2 feet from the edge of the pavement.
• Super elevation areas: In this method, when rolling the super-elevated areas, care should be taken when operating the roller so as not to disturb the elevation.
• Compaction of edge lope: This method should be done after the embankment has been completed. The rolling of slops shouldn't exceed 2:1, and the slopes should be rolled before the fill material has cooled to below 125 degrees Fahrenheit.

How to choose HAMM asphalt rollers

When it comes to selecting the right asphalt roller compactors with grades for a particular project, it is important to take several factors into consideration. Among the things to consider when shopping for an asphalt roller are project requirements, which includes the size and the type of the roller; weight, terrain, and access; fuel efficiency and emission standards; advanced technologies, and safety features.

It is important to note that different projects will require different kinds of asphalt rollers, so it is important to first define what one's needs are before entering the market. The project requirements will determine the size and type of roller that one needs to get. Some rollers come with a combination of drums, while some only have a single drum. If, for example, a steel or a smooth drum roller is used on an asphalt concrete pavement, a static kneading roller would be a better option for compacting an asphalt base.

Asphalt compactors are available in different weight categories. The weight of the roller chosen should be sufficient to provide the necessary compaction without overloading the subgrade. Additionally, the terrain and access of the roller require that one chooses a roller that can be moved and used around the area freely. It should be able to navigate through all the job sites' terrain and obstacles.

It is not uncommon for clients to ask about the fuel efficiency of an asphalt roller. In recent times, this has become a major concern for buyers. Selecting an asphalt roller that has good fuel consumption helps reduce operating costs and environmental impact. Emission standards also play a major part in the selection of an asphalt roller by buyers. Many of them are concerned about the effect of these machines on the environment.

Technology has influenced a lot of industries, and the machinery industry is not left out. Many machines manufactured today come with advanced technologies such as intelligent compaction that provides real-time feedback on compaction performance. Because of the many injuries that have been recorded over the years, especially with this machine, buyers are more concerned about the safety features of an asphalt roller. These safety features could be emergency stop buttons, ROPS, and antivibration systems, to name a few.

Hamm asphalt rollers Q&A

Q1: What are the recent developments in asphalt roller technology?

A1: Intelligent compaction technology and precise control systems for temperature and moisture have been recently developed. Sophisticated electronic systems can now provide real-time data on pavement characteristics and compaction parameters to operators, enhancing the quality of the finished road. Other recent developments in technology include hybrid power systems for fuel efficiency and environmentally friendly solutions, paving width attachment to compact the edges of roads, and reducing the need for multiple machines, as well as 3D paving control systems and variable amplitude and frequency damping systems.

Q2: What are some tips for using asphalt rollers efficiently?

A2: Following the manufacturer's instructions regarding fuel type will save costs and ensure the machine's integrity. Prioritizing the daily maintenance schedule outlined in the manual and carrying out routine asphalt roller repairs will enhance performance and prevent downtime. The maintenance schedule usually includes daily lubrication, regular inspections, tightening loose parts, and replacing damaged components. Familiarity with roller controls before operation will also ensure better handling and improve safety.

Q3: What are some ways to improve asphalt roller efficiency?

A3: Choose the right type of roller for the task in terms of size, weight, and drum configuration. Ensure proper temperature maintenance of the asphalt mix to achieve optimal compaction and reduce the risk of defects in the finished surface. In terms of settings, use suitable vibration settings to achieve effective compaction and check the drum width of the roller to ensure overlapping with previously compacted areas to avoid unrolled sections.

Q4: What are some signs that an asphalt roller should be replaced?

A4: Unrepairable damage such as a fractured frame or drum may indicate that the roller has reached the end of its operational life. Another sign of replacement may be significant wear on the drums, resulting in reduced compaction efficiency.