FIRST ALBANIAN CONGRESS ON ROADS ASPHALT PAVEMENT. Innovation in Materials and Techniques for Road Maintenance. Carlo Giavarini

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1 FIRST ALBANIAN CONGRESS ON ROADS ASPHALT PAVEMENT Innovation in Materials and Techniques for Road Maintenance Carlo Giavarini SITEB Italian Asphalt and Road Association

2 We live in a changing world Worldwide economic crises and environmental awareness have shown the need for more durable pavements and increased recycling. Simultaneously, bitumen production has changed significantly. Regulations, asphalt materials and application techniques have been impacted. Road pavements represent an important welth for a nation: maintenance is essential in order to keep their value.

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4 Pavement condition index PAVEMENT CONDITION EXCELLENT GOOD FAIR COST = 1 (REFERENCE) 75% RESIDUAL LIFE POOR VERY POOR 40% QUALITY DECAY COST = 2 (VARIABLE VALUES) COST 6-8 TIMES 12% RESIDUAL LIFE PAVEMENT AGE- YEARS

5 Evolution of bitumen production Bitumen is a unique, viscoelastic, inert, stable material, 100% recyclable. Bitumen production has changed over the past two decades. Crude oil availability has changed. Economics and demand for lighter products have driven the refining industry to modify its processes. Bitumen has become a specialty product as opposed to a previous (cheap) commodity product. The impact is significant from the market and technical standpoint.

6 Bitumen Price Evolution (ARGUS) End March 2010 [$/t] March 2012 [$/t] Italy Netherland Spain Iran Bahrain Tailand Singapore Japan New Jersey (USA) West Gulf (USA) Bitumen Market Barcelona 2012 Est Gulf (USA)

7 NATURAL ASPHALT The market of natural asphalt is very little respect to the bitumen produced in the oil refineries. It is mostly used as an additive for the conventional bitumen to improve some of its properties, due to the addition of asphaltene-rich components. The increased prices of bitumen have reduced the cost-gap between natural and industrial product. Natural asphalt is not classified and not subjected to REACH certification, beeing a «natural» substance.

8 EVOLUTION OF PAVING TECHNIQUES Since 1970 the asphalt industry has decreased its emissions by 97%. New technologies make the industry even greener Recycling and Rubblization Porous Asphalt: Draining Water & Noise Absorbing Coloured Asphalt Ecological (TiO2) and Anti-ice Asphalt Cold Techniques: Emulsions/Foamed Bitumen Warm Techniques Perpetual Pavements

9 RECYCLING (AND RUBBLIZATION) Asphalt can be easily reused many times both in situ or in other places, by applying cold or hot technologies In U.S. and many other countries, asphalt industry is number one recycler It also recycles materials from other industries (used tires, roofing shingles, etc) Rubblization of damaged concrete pavements with an asphalt-rubber overlay is a popular (and economical) rehabilitation approach in U.S. and other countries

10 Porous and Traditional Asphalt Pavements Primary use: improve surface friction & reduce splash and spray (and tyre/pavement noise)

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12 Modification of bitumen by addition of polymers Phase inversion

13 POLYMER MODIFIED BITUMEN PRODUCTION in 2010 (% of total bitumen sales, from EAPA) Italy 13.3 % Austria 35.0 % Belgium 24.4 % Denmark 5.0 % Finland 0% France <10% Germany (2009) 23.0% Japan 20.1% Norway 13.0% Poland 22.0% Spain 14.3% Sweden 6.0% U.K. 8.0% Turkey 4.0%

14 COLOURED ASPHALT

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16 ECOLOGICAL (POLLUTANTS ABSORBING) ASPHALT

17 Cold Techniques: BITUMEN EMULSIONS* Besides the traditional use as a bond (tack) coat and soil stabilization, emulsions are used for: Cold Mixes (bituminous mixes made with emulsions) Cold Recycling (emulsion restores the required cohesion) Surface Dressing (Chip Seal) Microsurfacing (Slurry Seal) * 8 Million Tons Worldwide

18 Using the right technique in the right place Surface dressing is a thin wearing course made of superimposed layers of gravel and bitumen emulsion (we can have one or more layers) Slurry seal is made by cold mixing fine aggregate and emulsion; a very thin coating is spread for the reneval of worn wearing courses (no compaction) Such techniques are cheap, improve rugosity and watertightness and can be used for preventive maintenance

19 WARM ASPHALT The last frontier of the paving technology to cut fuel consumption and production of greenhouse gases Temperature of the Asphalt Mix kept in the range C by improving the workability in many ways, mostly based on two principles: mechanical production (foaming) additives (waxes, zeolites, polyfunctional) 30% of all asphalt in U.S. Increasing amounts. Recommended by NAPA and EAPA.

20 Half-warm Asphalt Produced at temperatures lower than 100 C, generally between 70 and 90 C. Application conditions amenable to an even lower temperature. The binder being either an emulsion or a foamed bitumen or simply a bitumen. Properties of the asphalt layers not significantly differing from conventional ones

21 FUEL CONSUMPTION & CO2 EMISSIONS WHEN HEATING 1 Ton OF WET AGGREGATES

22 WE NEED A COMMON STRATEGY Warm mixes were invented in Europe, but developed mostly in U.S. (2% in EU vs 30%, or 100 million tons in U.S.) The Americans understood immediately that it was the right answer to reduce fumes There are too many different ways to produce warm mixes in Europe We should probably chose which one to develop We should explain their advantages and produce them at competitive costs also in Europe

23 PERPETUAL (LONG LIFE) PAVEMENTS Concept introduced in 2000 as «an asphalt pavement designed and built to last longer than 50 years without requiring major structural rehabilitation or reconstruction, and needing only periodic surface renewal in reponse to distresses confined to the top of the pavement» The concept is based on mechanistic-empirical studies validated by practical experience and modified to allow the input of limiting strains

24 PERPETUAL PAVEMENT DESIGN Based on an iterative approach in which the pavement response in terms of stresses, strains and deflections is used to estimate the allowable number of loads to failure The design considers limiting strains below which damage does not occur and it is not accumulated Two factors are critical: bond strenght (between the layers) and stress levels in the base layer ( softwares are available from asphalt agencies)

25 SIMPLIFIED FLOWCHART OF PERPETUAL PAVEMENT DESIGN

26 PERPETUAL PAVEMENT CONCEPT Structural rutting can occur Repeated tensile loads fatigue the pavement at the base

27 CONCLUSIONS Asphalt techniques and materials have changed significantly in the last 20 years. There is a common trend to move towards performance related specifications. Smart engineering will replace traditional pavement concepts. The move towards greener /durable pavements will greatly stimulate the innovation trends.

28 PADOVA NOVEMBER 2012 THANK YOU FOR THE ATTENTION Area m 2 Exhibitors 200 Visitors 9.000