Deficiency of seasoned equipment operators on site to run compactors to arrive the desired quality of work is posing challenge for today’s road contractors. The challenge is coming in the face of present days sophisticated asphalt mix designs, ever increasing demand for better quality, coinciding with mounting pressure on time schedule. The challenging situation is posing a bigger question in front of road contractors that how to apportion limited labour resources in a logical fashion, primarily to operate the compaction equipment. The logical answer to correct this anomaly would be adoption of intelligent compaction systems into the equipment so as to arrive at the desired quality and also to bring in operational efficiency of the compaction equipment involved in executing the project.
Achieving requisite density, for either soil or asphalt is more difficult. In an Indian situation from the contractors perspective, it can be argued that an experienced compactor operator can always help in getting the right amount of density as intelligent compaction systems are yet to find their way in getting adapted in a large way in the country. But having an experienced operator doesn’t necessarily guarantee success. Though the experienced operator can usually identify and adapt to these problems much faster than the inexperienced operator, but there is always the menance of unacceptable compaction. However, with equipment having intelligent systems fitted, “guesswork” would be out of compaction.
To put it simply, intelligent compaction systems automatically measure and control the energy output of a roller’s drum. They were introduced in the early 1990’s now several manufacturers offer such technologies for either their line of soil compactors, asphalt compactors or both. Though each manufacturer’s system is different in its specific execution, all are designed to work in generally the same way-measuring and reacting to the changing stiffness and material being compacted.
For both soil and asphalt rollers, intelligent compaction systems utilize devices-in some cases a set of accelerometers to measure both the horizontal and vertical reaction of the drum, it is compacting. At first when the material is soft, most of the drum’s energy is directed into the work surface and little reaction is read by accelerometers. But as the material stiffens (meaning essentially it’s becoming more dense or compacted), less energy is transmitted into the surface and more is reflected back into the equipment.
This automatic stiffness measurement and control of the drum output goes a long way toward taking the guesswork out of compaction, helping to ensure optimum density results while preventing material damage. However, this technology does little to prevent operators from working on asphalt, that is too hot or too cold. That is why several intelligent compaction system include a mat temperature sensing capability.
Benefits of the Technology
However elaborately, as per the benefit goes, maximizing compaction density, minimizing material damage and avoiding mistakes are huge benefits those are associated with intelligent compaction systems. Intelligent compaction system goes on to check possibility of under compaction, over compaction or other problems and as a consequence goes on to offset extra expense or largely potential of reputation damage of the contractor.
But there are other benefits associated with intelligent compaction that is driving demand for this technology. Prime among these includes, protection of the contractor’s capital equipment investment. When over compacting a surface, whether asphalt or soil, the operator is not only running the risk of damaging the material but the roller too. As stated earlier that the drum vibration energy is directed into the work surface when the material is still soft and receptive to compaction. As the material begins to stiffen, it is less and less capable of receiving compacting energy and this energy is reflected back to the roller. Over time, this practice is prescription for a short equipment lifespan. Using an intelligent compaction system helps alleviate equipment concerns. This is because the energy adjusts as the material achieves density, there is less potential for energy to be redirected back into the roller. This reduces required maintenance and encourages longer service life.
Another benefit of intelligent compaction systems is increased efficiency. With intelligent compaction systems fitted, the operator with requisite or little experience may find that the surface may require three or four passes for optimum compaction. It would be found that after qualifying results against an independent testing device, there is no need to conduct independent testing because the roller does it on the fly. Instead of wasting one or two passes and taking extra time to test the material, the job has been completed with less effort. Decreased effort means less time required on the job, less fuel to burn, less maintenance, less wear and tear hours on the equipment and altogether better chances of meeting deadlines and receiving bonuses.
Knowing that the best possible compaction results has been achieved in shortest period of time is good, but it’s better if one can prove it. Today all contractors must agree to some type of guarantee for their work. This is typically specified in the bid and it locks the contractor into a particular quality or performance standard. Because of this, contractor should document results achieved on every job in order to offer some sort of recourse in the event the problem arises within the given warranty period. If this documentation isn’t available or sufficient enough to prove that the job was right in the first time, the road contractor may be required to come back and fix the problem at his own expense. To combat this, most intelligent compaction systems offer a way to document job site results through the use of on board printers.
Though intelligent compaction system provides assorted benefits but for larger acceptance and optimum utilization of the benefits in the country, provided through the technology, Mr. Manoj Garg points out that NHAI has to play an important role. This has to be through NHAI’s emphasis on compaction of the road rather than on its thickness. This will ensure desired quality element to be brought in roads and in turn larger adoption of intelligent compaction systems in compactors in a large way. Similar views are expressed by Mr. Rajesh Sharma. He highlights NHAI in connivance with the compactor manufacturers can disseminate information among the contractors fraternity the utility of intelligent compaction systems.
Nontheless, for greater acceptance of intelligent compaction systems have to come from the contractor’s fraternity who have to educate themselves in understanding the advantages intelligent compaction systems offer.