Santiago Metro, Chile

CONTRACTOR: FERROVIAL AGROMAN / OHL

CLIENT ISSUE

Two additional underground lines, Lines 3 and 6, have been under construction to extend the vast Metro network in Chile’s capital city of Santiago. Line 3 includes 19 stations and 21.7 kilometres of running tunnel to very demanding sprayed concrete strength development and permeability specifications. Line 6 called for 15.3 km of running tunnel and 11 stations with sprayed concrete strength requirements beginning at 12 hours.
The total amount of sprayed concrete for both lines is approximately 500,000 m3 that was to be placed until mid-2016.

Line 3 is split into six sections, with four contracts awarded:

Sections 1 and 2: Awarded to OHL
Section 3: Awarded to Ferrovial Agroman
Section 4: Awarded to Isolux/ICA
Sections 5 and 6: Awarded to OHL

All the contracts awarded are led by large Spanish companies accustomed to working with traditional European admixture and accelerator suppliers.

THE JOB / THE CHALLENGE

The technical specifications for the sprayed concrete for Santiago Metro Line 3 required the strength development to fall within the J2 and J3 classes, with a four- hour slump retention time and a 25% strength drop over the control sample without accelerator. This was a particularly difficult challenge considering that all local cements are blended cements, which generally do not help early strength development.

THE SOLUTION

Normet Chile identified the challenge much earlier than the competition and provided the contractor with trial support and technical advice ahead of the competitors. Intensive worksite training with contract personnel was provided, and on-site troubleshooting strengthened our position with the customer, allowing Normet to defend its leading position in the project.

Extensive field trials were conducted to compare three brands of accelerators using three brands of cement. Based on the strength results and intensive Normet field service and technical advice provided during the trials, OHL and Ferrovial selected Normet’s TamShot 70 AFC and our package of knowledge and support. Our accelerator supply will account for 80% to 100% of demand for Line 3.

Most of the sprayed concrete mixes were supplied by ready- mix companies, who use Normet competitors products.

Normet Chile’s strong position with the Metro contractors and our sprayed concrete know-how and good contacts with the ready-mix industry allowed us to negotiate with one of them as a strategic partner for different contracts.

PROJECT OUTCOME

When Ferrovial Agroman was awarded the contract for Section 3 of the Santiago Metro project, the supply of concrete spraying equipment was being negotiated in Spain by its purchasing department. Ferrovial Agroman had not worked with Normet equipment in other parts of the world so the local contract management was not interested in an equipment quotation. As the project developed in its early stages and Normet TamShot 70 AFC accelerator was showing good performance, the companies forged a closer relationship, and the contractor came to see Normet Chile as a problem-solving company. When the equipment supply negotiations from Spain dragged on and a commitment on delivery date could not be achieved, Ferrovial approached Normet Chile for a solution. We offered two Spraymec Alpha 1430 PCs in a package with TamShot 70 AFC, allowing the contractor to avoid any project delay and use the product that was the best performer on-site.

In addition, large volumes of Normet’s TamCem 65C, TamCem HCA and TamCrete silica fume admixtures were extensively used in readymix as well as shotcrete mix supply site plant.

The technical knowledge of Normet’s product managers, their ability to serve as contractor advisors to meet the demanding Metro specifications, the good product performance and long working hours helped to position Normet Chile’s Chemicals division as specialist market leaders in the Santiago Metro project.