Penetron Crystalline Technology Seals Green Heart Capillaries

The Green Heart office complex in Belgrade, Serbia, was officially inaugurated in March 2020 with the completion of the third and final office building. The developer specified the full range of Penetron crystalline technology to ensure waterproof below-grade structures for the office complex.

Over the past three years, strong construction activity in Belgrade, Serbia’s capital, has fueled consistently strong growth in the demand for office space. Most of the new projects are located in the central business district of New Belgrade.

The GTC Group, a leading commercial real estate developer active in Eastern and Southern Europe, launched construction of the €60 million ($70.5 million) Green Heart project at the end of 2017, completing work in just over two years. Construction included the comprehensive renovation of two existing buildings (each with four floors) and the construction of three new buildings (each seven floors tall). Located on Milutina Milankovića Boulevard in the New Belgrade central business district, the Green Heart business complex now comprises five buildings with 46,000 m² of office space and three underground levels of parking accommodating 900 cars.
 

Deepest Excavation in New Belgrade

“The Green Heart complex has a very unique architectural style that creates a verdant environment, giving you the feeling of being in a park, despite the downtown location,” says Theodor Mentzikofakis, Managing Director of Penetron Hellas. “Every floor features terraces lined with trees, adding to the naturalistic impact. Also, ZOP Engineering, the project builder, paid attention to the use of sustainable materials and processes.”

Planned with three underground levels to accommodate the parking garage, the initial excavation phase at the site made the Green Heart project the deepest excavation ever undertaken in the New Belgrade business district – eight meters below the water table. Because of the proximity to the confluence of the Danube and Sava Rivers, the site experienced an abundance of groundwater. Lever Engineering, the project subcontractor for waterproofing, realized a robust waterproofing solution was required.
 

Offering a Superior Solution

Penetron West Balkans, the local support team in Belgrade, worked with the local Penetron distributor for Serbia to offer an optimal technical solution.

“At the time, two competitors had offers on the table at Lever Engineering to waterproof the below-grade concrete structures,” adds Theodor Mentzikofakis. “However, once the Penetron West Balkans team and the project manager at Lever Engineering reviewed the specifications and aggressive project deadlines, we recommended a solution that would meet their budget constraints as well as their tight construction schedule.”

The full range of the Penetron System was incorporated into the Green Heart project. PENETRON ADMIX was used to treat around 2,300 m³ (3,000 cubic yards) of concrete for the foundation slabs and underground garage structures. The resulting construction joints were permanently sealed with PENEBAR SW-55 waterstop strips. The ongoing repairs to the existing retaining walls were carried out with a combination of PENEPLUG, a rapid-setting, crystalline compound that quickly stops active leaks, PENECRETE MORTAR, to fill cleaned and prepped cracks, and finally, a layer of PENETRON, a crystalline material, as a topical application to the repaired surfaces to ensure a waterproof structure.
 

A Value Engineering Solution

PENETRON ADMIX, a permeability-reducing concrete admixture, is delivered in premeasured, soluble bags. These bags are simply tossed into the concrete mix during batching, providing a simple solution to ensure a waterproof concrete mix. The active ingredients in the admixture react with moisture to form insoluble crystals that self-heal and seal all micro-cracks, pores and capillaries in the concrete, becoming an integral part of the matrix, making the concrete impermeable.

“Whilst the concrete was placed, the waterproofing was being placed at the same time. This ensured a dry basement structure and allowed the construction team to stay on schedule,” says Theodor Mentzikofakis. “And today, Green Heart is a new home to many companies.”