Italian company SAM S.p.A. have drawn up the first working agreement using the patented production of warm asphalt mixes with the introduction of moist sand into the mixer
SAM SpA started out in the road building industry in 1952 in Monforte d’Alba, Northern Italy; in 1970 it moved its operations to Alba, where it extended its activity to produce asphalt mixes and road pavements. Currently SAM is involved in road and motorway construction and maintenance, the production of certified asphalt mixes, civil and industrial city-planning projects, hydraulic projects and environmental remodelling, reinforced concrete works, as well as aggregate extraction and processing.
Last year SAM decided to back up its historic plant in Alba (120 tph production) with a new innovative model, making it one of the most ground-breaking and state-of-the-art asphalt producers.
The company purchased a new TOP TOWER 3000, a complex plant completely fitted out for use with all types of additives, selected pre-processed RAP materials and, above all, warm asphalts. And this is why SAM is considered an Italian market leader in the production and sales of warm asphalt using EBE technology, in conjunction with LEA®-CO France, offering cutting-edge products with energy savings in an environmental-friendly manner.
The decision to distinguish itself from its competitors by using new techniques for asphalt production was a particularly important challenge for Mr. Musso, the Technical Director, and was also welcomed with enthusiasm and determination by other members of the technical department, including Messrs Viberto and Peperone who, together with Ferruccio Peperone from the engineering staff, took into consideration and carefully analysed all cutting-edge technologies for high performance asphalt production while leaving a friendly footprint on the environment.
The main consideration during technical discussions was to create a high performance plant (to meet the requirements of clients and their own road building crews), but above all to have one of the world’s state-of-the-art plants from both the technological and ecological points of view (low atmospheric emissions, low noise levels, low energy consumption, maximum use of RAP, etc.) and, thanks to the vast site experience of the technical staff, it was easy to create a positive team spirit during the design stage of such a complex plant.
The plant consists of a series of high capacity cold feeders (30m3) which have the possibility of truck-loading. The plan is to protect them with special covering in the near future, together with the sand deposits and processed RAP material. Cold feed protection, especially for small size aggregates, is essential for reducing moisture, with consequent reduction in burner consumption and plant emissions. It also guarantees high plant performance in rainy seasons and standardizes the quality of recovered fines over long periods of production.
Another important investment made by the company was the purchase of a RAP processing plant producing 3 aggregate sizes (0-8mm, 8-12mm, 12-25mm), which are quality-controlled in the company laboratory, to fully guarantee reliable, high-performance asphalt production even when using high percentages of RAP.
The plant has been fitted with 3 cold feeders for RAP material, with the possibility of feeding the recyling ring and/or the mixer line. This means maximum flexibility for the producer, depending on the characteristics of the final mix.
In order to reduce emissions into the environment, the dryer and heater burners use methane gas and the tanks are fitted with 200 mm up-graded insulation, even on the bottom, which reduces thermal bridging to a minimum and therefore reduces heater emissions.
The company also aims in specializing in the reuse of crushed recycled rubber granules to produce soundproof, eco-sustainable mixes. Once again, priority has been placed on respect for the environment, combined with the recycling of materials which otherwise would have limited reuse.
SAM’s main focus is placed on the production of warm asphalt mixes using LEA®-CO technology and, with this in mind, a full-scale production day was organized for the 11th May 2012 in the presence of FAIRCO’s M. Romier, the ATS laboratory which is controlling the laying operations on the Torino-Savona motorway, in addition to the head of the SAM laboratory and representatives of the Technical Department of the Alba Municipality.
Work was concentrated on forming a comparison between a traditional hot mix asphalt and warm mix asphalt. Production began with an ANAS binder (O-25 mm), using 30% RAP at a production temperature of 160°C and laying a 10 cm layer of asphalt. Production then changed to warm mix with an identical grading curve and RAP content, but with the production temperature being reduced to around 95°C.
The warm mix was laid next to the hot asphalt mix in order to be able to carry out checks at regular time intervals on this stretch of road which was submitted to a uniform amount of traffic in both directions. In the meantime, the laboratories took a series of asphalt samples with a view to conducting traditional tests before and after laying the pavement.
Laboratory results proved to be positive and so the laying of the road pavement went on well into the afternoon, with an excess of 600 tons being used. Laboratory tests continued in order to check the workability of the finished asphalt mixes in relation to residual moisture, final temperature and percentage of liquid additives, to ensure that the road crew was supplied with an easily-workable material for the paver finisher to lay and the roller to compact.
The main advantages were clearly the complete elimination of vapours and smells when unloading the asphalt onto the trucks and above all during laying and rolling operations. Both safety and comfort were undoubtedly improved.
Secondly, RAP materials were utilized without difficulty at low temperatures, putting less stress on the bitumen contained in the mix. And benefits will undoubtedly be seen over time, thanks to the pavements greater durability.
Thirdly, dryer burner consumption was reduced by about a half, with subsequent reductions also in atmospheric emissions.
SAM S.p.A. is firmly convinced that only through passionate dedication combined with the use of new technology can they reinforce their presence on the market and, at the same time, guarantee that Public Authorities can operate smoothly and that the general public can benefit from a smaller environmental footprint and a better quality product in terms of road performance and durability. Another issue worthy of mention is the possibility of making maximum use of Secondary Raw Materials in road construction.