Concrete continues to be specified for a number of commercial projects. Whether your client is looking to achieve specific aesthetic goals, needs to meet budget limitations or has a unique structural problem to solve, concrete is often found to be the solution. In this article, we look at some commercial concrete projects that have received recognition and acclaim over the past few months.
Out-of-the-box application of bag concrete at Gensler’s office
The main entrance foyer to Gensler’s design centre in Morristown, New Jersey, received an innovation award from Concrete Construction. Initially, the plan was to pour 3.8cm of 5 000 psi concrete over a wood substrate with a bond breaker and wire mesh reinforcement and to fill the control joints with polyuria. The building is 100 years old and the concrete was polished to a 3 000 grit on the fourth storey.
Due to a mechanical entry door that was installed, the elevations changed, which left a much smaller clearance for flooring elevation. The contractor used a rapid setting concrete mix to achieve 5 500 psi in just three days while also ensuring that the concrete was strong enough with the depth that was provided. The floor was formed in a grid pattern and each panel was cast in place.
Over 200 bags of concrete were used to complete the pouring and forming portion of the project and it took the team two weeks to complete the polishing. The result is a stunning foyer and entrance at the revamped Gensler office.
Extra green polished concrete applications at Northern Alberta Institute of Technology
The 2016 Concrete Surfaces Polishing Award for the best educational concrete polishing project went to Desco for their work at the Northern Alberta Institute of Technology Centre for Applied Technology, NAIT CAT, in Edmonton, Alberta. The LEED Silver certified institution is renowned as a centre of excellence for simulated learning where students can experience real-word situations in classrooms and labs. The polished concrete flooring in high traffic areas is one of the sustainable features of the project.
Radiant heating in floating concrete slabs was placed on top of the structural concrete slab. Various mix designs were used to achieve the client vision and large mock-ups of the floor assemblies were constructed on site. The mock-ups were cast in place on top of the structural concrete slabs before being removed so the final flooring could be installed. Grinding processes were used to expose mainly large aggregate and polishing ensured a high gloss sheen.
A significant amount of control joints and expansion joints were needed to accommodate the radiant heating lines installed in the floating concrete slab. Significant effort was taken to colour-match the filler that was used in these joints. The grout itself was also colour-matched to limit streaking or colour variation and decorative concrete dye was used to mirror other architectural details of angular intersecting lines.
Parallel structural columns were constructed with a small gap between them. This gap was polished to match the adjacent floor as a design detail. The design team had to take particular care to avoid damaging the exposed concrete columns with this polishing process because the polishing tooling was only slightly smaller than the gap.
Polished and dyed concrete at the Liberty Center in Ohio
The Liberty Center in Ohio is a real estate development featuring the first enclosed mall to be built in the US since 2007. The owners of the development, Steiner and Associates, were able to save over US$1 million by installing polished concrete floors in lieu of ceramic tiles.
The building was designed to look like a rustic, old steel mill with exposed iron, bricks and steel forms, including a 27m tall, faux smokestack on the exterior. Natural polish as well as dye were used to create unique solvent-based colours that were matched to accentuate the look and feel of the mall.
Polished concrete enabled the architect, KA inc., to achieve the aesthetics and cost savings that were sought by all parties involved. The project recieved the retail category award by Concrete Surfaces in 2016.
New technologies and finishes in concrete and cement
• The use of fibre-optics or light reflecting aggregates and pigments in flooring has become popular in outdoor entertainment areas, on concrete staircases and in nurseries, providing a maintenance-free, safe alternative to traditional night lights.
• Titanium dioxide as an additive to the surface of concrete has sterilising and deodorising properties, resulting in what is becoming known as self-cleaning concrete.
• Experimenting with innovative applications on concrete floors fills the gap between what is physically available and new possibilities, allowing new products to be brought to commercial fruition.
• Stained concrete finishes adds a sense of depth to any surface.
Full thanks and acknowledgement are given to www.concretenetwork.com, www.concreteconstruction.net and www.descoalberta.com and for the information contained in this article.