Machine control for a roller is a tool that can be applied by contractors during compactionwork. The machine control includes a function that can sense how packed a surface the rollerpasses is, the degree of compaction is then reported in a dimensionless Compaction MeterValue (CMV) number. With the help of the compaction function, it is possible to reduce thenumber of static plate loads that must be carried out in accordance with the Swedish TransportAdministration's requirements. From a cost point of view, it is positive if the number of plateloads decreases as they are very resource demanding, the machine control can thereforecontribute to a cost saving. The roller's machine control also includes a function that can sensethe height coordinate of the compacted road surface, which can reduce an engineer’s time outon projects.NCC's road and construction department in Umeå city applied machine control on one of itsprojects carried out on behalf of the Swedish Transport Administration. The project is aEuropean road E09 which is 136,000 square meters. According to the Swedish TransportAdministration's requirements, for traditional statistical acceptance control, five to eight staticplate loads must be performed every 5000 m2 of road area. For an acceptance control withmachine control instead of performing the traditional acceptance control, the number ofmeasuring points is reduced to one or two measuring points per 5000 m2 of road.From identified literature, it becomes clear that the advantages of machine control outweighthe few disadvantages identified. Literature states that when applying machine control, it ispossible to reduce costs associated with packing work by 54 percent, it also leads to anincreased quality assurance where 100 percent of the road body can be controlled. Fortraditional statistical acceptance control, only 1 percent of the road's bearing capacity ischecked with random plate loads.In the study, the impact of machine control on quality and quality work has been explored.Statistical acceptance control is performed with a maximum of eight randomly selected pointcontrols on a surface that can be up to 5000 m2. If this is compared with the roller’s compactionwork where the entire control object is being validated with the compaction computer in theroller first, in addition the weakest point or points are also checked. Then it is possible to makea reasoning that about 1 percent of the control object is checked during statistical acceptancecontrol while 100 percent of the control object is inspected during acceptance control with themachine control system. This reasonably entails a higher quality of the control object. However,there are uncertainties with the measured value CMV, which does not hold any dimension andis completely dependent on how the roller is calibrated. This means that CMV cannot becompared between different rollers on different projects if they are not calibrated equally.Therefore, we suggest that contractors should always calibrate their rollers in the samemanners.vA profitability calculation has been performed where NCC's projects are evaluated and it iscalculated how the usage of machine control has affected the project, an estimated cost isestablished for the use of machine control and a cost if it had not been applied. The calculationis based on interviews with relevant people within construction companies as they haveexpertise in handling the equipment.The profitability calculation showed that the realistic outcome for the project meant a saving of35 percent regarding costs that can be attributed to compaction work. The literature statedthat savings could reach up to 54 percent, it seems to be in the upper range as the reasonableoutcome is lower by 19 percentage points. Machine control still contributes to improvedprofitability but not as strongly as research claims, it may also be due to the fact that theprofitability calculation is based on an individual project, to get more reliable data moreprojects would have had to be evaluated.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:ltu-91295 |
| Date | January 2022 |
| Creators | Brännström, Oscar, Rova, Olle |
| Publisher | Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser |
| Source Sets | DiVA Archive at Upsalla University |
| Language | Swedish |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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