The largest bridge in Tunisia is waterproofed with Parafor Ponts

Special edition #1April 2009| www.siplast-international.comPont Rades-La GouletteThe largest bridge in Tunisia iswaterproofed with Parafor PontsAn international project40,000 m² of Parafor Pontswaterproofing systemapplied by ProbatAn international project of 40,000 m² of bridge-deck waterproofing,using the Parafor Ponts SystemUntil now, to bypass Tunis on its east side, it was necessary to takea boat. Today, the Rades-La Goulette Bridge crosses the lake ofTunis and, in this way, smoothes and disencumbers the Tunisiancapital’s traffic loads. Not only is the largest bridge in the country,but it is also a technical prowess.The Parafor Ponts waterproofing system was applied by ProbatCompany/Tunisia.Description of an ambitious project.With a total overall span of 2,000 meters, the Rades-La Goulette Bridgelinks La Goulette at the north to Rades at the south. This concretestructure is divided into three subspans of 70, 120 and 70 m and has twolanes on each side. With its variable height, its two bridge towers and itscable stays, it constitutes the most spectacular part of the project. It hastwo accesses, to the north, multiple box girders, cast on centring and, tothe south, a traverse of precast pre-stressed girders.The design of this bridge is based on state-of-the-art technology,including very deep foundations for earthquake resistance. Its deck hasfour webs of variable height, four types of pre-stressed elements, one ofwhich is extrados type (this is a very rare feature).An international projectBuilt in cooperation between Japan and Tunisia, the project was financedby Japanese banks. It was managed by a group of Japanese engineeringfirms (Nippon Koei, PCI) and Tunisian engineering firms (Scet and Studi).As to the bridge itself, it was erected by contracting firms from Japan(Taisei and Kajima), Tunisia, Egypt (Arab Contractors) and France (VSL).A number of French engineering firms also contributed (Setec, Ingérop,JMI).40,000 m² of Parafor Ponts waterproofing systemapplied by ProbatProbat is a Tunisian distributing & contracting company, one of thespecialities of which is waterproofing civil engineering works. It wasentrusted with the waterproofing since its craftsmen are very familiar withSiplast products, having been trained at the Siplast Training Centre inMondoubleau (France). The Parafor Ponts system (read the inset) wasselected for its bonding qualities and for its light weight (5kg/m²),important requirements on this structure. Furthermore, it is rapidly laid inone pass, then it directly receives the wearing course. The economicaspect is also favourable to Parafor Ponts, a complex that is lessexpensive than other systems. Finally, it was essential to propose asystem holding the Technical Assessment from the Setra¹, technicalbranch of the French Bridge and Roadway Authority, the reputation ofwhich is recognised internationally.From the viewpoint of the Japanese project management firm, Siplast-Icopal, present in Japan for nearly 15 years, can certainly be considered

as a reliable partner. For the design of the waterproofing work, theRades-La Goulette Bridge required a very meticulous detailed layout,given its architecture with its curves and their countering inflected curves.The work itself was executed on time. This required some work at night.Inaugurated on March 21 st , 2009, the Rades-La Goulette Bridge will becarrying a traffic load estimated at 30,000 vehicles per day, 15 to 20% ofwhich will be heavy road vehicles. The drivers will be avoiding the dailytraffic jams.A major step in the development of Greater Tunis.¹SETRA – Service Technique d’Etudes des Routes et Autoroutes (Road and HighwayTechnical Study and Design Agency)Jobsite identification sheetContracting Authority:Ministry of Infrastructure, ofHousing and of TerritorialPlanning, General Bridge andRoadway AuthorityEngineering company:Nippon Koei CO ltd Group.Technical inspection body:Pacific ConsultantInternational (PCI), CentralTerritorial DevelopmentAuthority (SCET Tunisia),Tunisian EngineeringCompany (STUDI)Contracting company:group comprising Kajima(Japan) and ArabContractors (Egypt)Waterproofing contractingcompany: ProbatSiplast products: ParaforPonts membrane, SiplastPrimerParafor Ponts: the reliable, fast and economical single-plysolution, holding a Technical Assessment from SetraParafor Ponts is a prefabricated single-ply membrane (as describedin Booklet 67, 1 st Chapter of the CCTG²). Full-surface welded on theSiplast Primer coated concrete deck, it can be used under certainconditions on a metal structure. It then directly receives the macadamlayer, without protective layer.Its benefits: No excessive loading of the structure: the waterproofing weighsjust 5kg/m². Fast application. Inexpensive. Allows for light traffic on the jobsite. Parafor Ponts constitutes an excellent interface between themacadam and the concrete deck, and limits any risk of slippagebetween the various layers.Packing: Standard roll: 1m x 8m, weight: 49kg. Other packings in longer rolls are possible for mechanisedapplications.Reference documents: Technical Assessment for civil engineering structures, issued bySetra. Siplast “Road-Bridges” Design and Installation Manual.²CCTG – Cahiers des Clauses Techniques Générales (General Technical ClauseBook)12 rue de la Renaissance - 92184 ANTONY Cedex - Francecontact@siplast-international.com