THE TECHNICAL ASPECTS AND FUTURE OF THE CANAL
The chambers of the new locks system are 427 m long, 55 m wide and 33 m deep. They act like giant lifts that raise the ships 27 m above the level of the ocean to the level of the artificial Lake Gatún and the navigable route that crosses the Isthmus of Panama, to be then lowered down again on the opposite side, ready to set off on their oceanic voyage. Next to each chamber the Consortium has built enormous storage basins where the water is recycled: they allow more than 60% of this precious resource to be saved, and then feed it back into the locks system. The “old” Canal, built by the Americans at the beginning of the last century, and which today still gives a return of 2.5 billion dollars, will continue to operate. The Panamanian authorities have already received more than 166 bookings between now and December. Estimates foresee that income from the Canal will double to 5 billion dollars a year once the new Canal has become fully operational.
The main client is still the United States, who on the 31st of December 1999 handed over administration of this precious waterway to Panama. But the Chinese are fighting back with their increasingly large merchant ships. So much so that the Canal authorities are already working on a future plan and are analysing the costs and benefits of a fourth route, maybe even larger than the current one.
The construction of the new canal required an enormous building site with head-spinning figures: 70 million cubic metres excavated, 290,000 tonnes of steel, 5.5 million cubic metres of concrete and more than 100 million hours of work. The jewel in the crown of the project are the 16 giant steel gates, built in Italy and transported via sea over the courseof seven years. The average weight of each gate is 3,000 tonnes and they carry out their task in just five minutes: to open and close the water chambers which – operating like enormous lifts – allow he ships to overcome the 27 m difference in level between the two oceans and the artificial Lake Gatún.
Through their subsidiary company Mapei Construction Chemicals Panama S.A., Mapei supplied various admixtures of the latest generation to manufacture around 5,500,000 m3 of mass concrete and marine concrete, used respectively to build the internal and external sides of the locks.
DYNAMON XP2 and DYNAMON XP2 EVOLUTION 1 were developed specifically to build the new Canal (see Realtà Mapei International no. 40, 42, and 46). After numerous checks, carried out in the purpose-built Mapeilaboratory in Panama, and cross-referencing the results with the GUPC laboratory, DYNAMON XP2 was chosen for use during the first six months of work on the project on both the Atlantic side, where they were using Panama cement, and on the Pacific side, where they were using Cemex cement.
The objective was to guarantee a service life of the work of 100 years, thanks to the use of a model that calculates the durability of concrete. After commissioning the plants producing the concrete and aggregates, several serious problems regarding a considerable loss of mechanical strength and durability in the concrete produced by the plants were solved. In this phase, Mapei’s support focused on various activities: a study and chemical and mineralogical analysis of the rawmaterials used (basalt aggregates, pozzolan and cement); technical suggestions for the correct choice in flocculants and coagulants employed to treat the waters used to clean the aggregates so that they would be more chemically compatible with the super-plasticisers used in the concrete mix; chemical and petrographic analysis; control of the pozzolanic activity of the basaltic fines from the cleaning operations to assess its use in the concrete mix and optimise its natural pozzolan content.
Following a request from the client, Mapei then started to develop a new product which could work well with the new mixdesigns being verified at the GUPC laboratory. Mapei technicians designed the formulation for a new admixture called DYNAMON XP2 EVOLUTION 1, with the name chosen to give a sense of continuity to the enormous amount of work previously carried out on the old admixture. This product proved to be even better at maintaining the workability and placing of the concrete at even lower dosage rates compared with the competitors’ products.
RENOVATING THE EXISTING CANAL
The project also included renovation work on the original Canal. Mapei offered their contribution to help repair and consolidate the foundations for the Gatún Lock, located approximately 30 m below ground and considered to be the most imposing reinforced concrete structure ever built. This building site used a particular type of mortar and to make it Mapei supplied PLANITOP 15, an one-component shrinkage compensated cementitious mortar ideal for form-and-pour and form-and-pump applications (which is manufactured in theUSA by Mapei Corp.), and MAPECURE SRA, a special curing admixture for cementitious mortars and concrete to reduce hydraulic shrinkage and the formation of micro-cracks.
SYNTHETIC WATE RPROOFING MEMBRANES
For the third set of locks – which completed the expansion work on the Canal - an environmentally and socially sustainable project was drawn up, called the Water Saving Basins project, to limit its impact on the surrounding area, the people and the environment. In so doing, 60% less water will be required: whereas normally each passage requires around 500 million litres of water, the new system will only need 200 million litres.
Mapei contributed to this work with the synthetic membranes SIBELON PVC-P. SYBELON trademark is owned by CarpiTech Sibelon. Manufactured at the Polyglass (Mapei Group) plants,the membranes were used to waterproof the auxiliary basins that recover and partially recycle the water from Lake Gatún. Developed specifically for hydraulic works, SIBELON PVC-P synthetic membranes, laminated to non-woven polypropylenefabric, were applied over a total surface area of around 800,000 m2. Characterised by their high resistance to UV rays and aggressive atmospheric agents, they guarantee a high level of durability over the years.
Mapei supplied numerous other products for completing this grandiose project, such as PLANIGROUT 300, MAPEGROUT 05/06, IDROSTOP PVC BI/BE, IDROSTOP MULTI, MAPEGEL UTT, IDROSILEX PRONTO, MAPEPROOF SWELL, IDROSTOP 10 and IDROSTOP MASTIC.