LIGHT GFRC FAÇADES CLADDING FOR THE CARREFOUR MALL OF BOGOTÁ.

The Project Management of the spanish firm Architectonic Concrete, S.L., for this project can be summarized as:

1.- Previous definition of cladding panels adapted to the architectural project.

2.- Supervision of the manufacturing and assembly budget study for definite budget making with local parameters.

3.- Definition and making of the first panel as a prototype, which was initially intended as 1,20 m. width, and nerved totally with GFRC, therefore saving the iron stud-frame.

With technical assistance of Francisco X. Regas in the Bogotá precast plant.

4.- Texturing of the prototypes by sand-blasting.

5.-With Architectonic Concrete S.L. advice, it is finally decided to manufacture the series panels in 2,40m. width, doubled than originally, variable heights and stud-frame reinforcement sollution.

Thus, halve the total panels ammount and speeding the rate of assembly.

Prices are then re-calculated by our precast client and he agrees on a rigourous assembly calendar.

6.- A strenght test is advised and done over a prototype panel skin, overloading it with water, up to 200 kg/m2, thus forcing large deformation but not appearing any fissuration on the panel skin, in spite of that load.

7.- Precast manufacturing of the panels run at 100 sq. m. /day, and façade assembly at the same rate.

With assembly tecnical assistance of “Architectonic Concrete, S.L.” at the woksite.

8.- The assembly advances in a synchroniced process, due to high speed required cycles: sooner free cranes by holding panels provisionally, then anchor panels permanent while crane comes loaded again.

9.- Cladding of the façades progress, untill full termination of its 5.000 sq. m. project.

GFRC-Studframe cladding for a Cartagena de Indias cement plant.

The new plant of the colombian cement manufacturer ARGOS is located next to the shore, in the Cartagena de Indias bay, that is surrounded by nice landscapes.

The tallest element of the plant, the preheater, has been cladded with precast GFRC pannels, understood GFRC is glassfiber reinforced concrete.

Architectonic Concrete, S.L. has provided technical assesment to all the main stakeholders and steps for this particular cladding sollution to be done: the plant owner, architects, precaster, and the assembling teams; about cost and schedule, detail definition of the elements, anchorage systems, precast manufacturing quality, and assembly proceeds.

The architects entitled for design wished this ventilated façade to resemble the shape of a modern sail, to evocate the discoverer Columbus, after who the plant itself is named.

These precast pannels are conformed as GFRC shells, half an inch thick, which are connected flexibly, to an extend, through embeds to an iron studframe, sized to each shell.

The whole element (shell + studframe) weights around 45 Kg./m2.

Diedral main face.

Diedral side face.

The total cladding is a by-faced diedral, forming a sharp edge to give a perception of volume and hide the panels back-face as well.

The average pannel size is about 6 m2 and for the total closure it is 3.000 m2.

Elevation means for all the elements was through a winch placed on ground. The heaviest pannels to lift were of 400 kg.

In order to reduce the façades exposure to pollution of the surrounding atmosphere, the pannels where coated with silicate pigments.

Also wind loads at 40 m/s. speed where integrated, while in design fase, as a potential stress to the elements.

GFRC-Studframe cladding for the Argos plant. Constructive details.

This image shows the back face of a pannel, while stocked, (it is 90º counter-clock when mounted).

Detail is an anchor plate serving the union with the "L" bracket support to the façade structure.

The iron studframe is calculated to sustain the stress due the wind loads, it is joined to the back of the GFRC shells (15 mm. thick), through L iron rods, embeded in the GFRC shell during the precast process.

This method for GFRC cladding pannel manufacturing was first introduced in USA, some 30 years ago, being a wordlwide standard now.

Bending and tensile resistance of this GFRC is higher than 10 Mpa (about 1.500 psi) at 24 h, thus allowing the whole precast pannel to demould next day without damage.

Pannels are fixed to the auxiliary structure of the building, through bolted unions, each comprising bottom to sustain self load and top to avoid tilt. That also makes pannel pre-positioning easier.

The back face of the whole cladding remain allways accessible to the maintenance services of the building.

Commercial buildings. Valencia, Spain.

This cladding was conceived after the presentation we did to the promoter and the architects of the main project, about the architectural concrete possibilities, white cement based.

As a consequence of that previous work, detail project was born quite optimal allready, taking cost, quality and execution schedule, into account as well.

Design included a moulded strip to fix external air cond. devices on it. White color was to be that of cement and selected agreggates, and the exposed surface of the pannels slightly textured by acid.

To make the most of the site own elevation means, pannels weight was limited to around 2 tones each.

A nicer looking modulation of precast façades benefit from L-shaped pannels to solve the corners cladding. So, "L" elements were precasted to match carefully those areas.

All the cladding fixings to the structure are bolted, providing the needed security and precision, the average work progress was of 8 or 9 pannels / journey (8h).

In this image, next to the silo, a previous prototype module can be seen, complete with window frames and glasses.

When it comes to an industrialized constructive solution, we insist allways in the importance of making a prototype or mock-up, thus helping better all the parties agree on the details for the whole future series.

Architectonic Concrete S.L. helped to agglomerate the whole cladding project and its execution, throughout the main concerned stakeholders of it.

Textured building's façade. Las Palmas de Gran Canaria. Spain.

This residential building is cladded with mass-colored architectural concrete pannels, by proper dosage of three different "black" tones, to resemble basalt-like.

The texture for the exposed surface was obtained by flexible skins, which can be cutted as for the intended pannel sizes, so avoiding fake joints.

Precast façade claddings allways require a detailed project for the elements explode, identifying type and series of elements and intended location for each. Precasters can help architects while in that desing phase, too.

Architectonic Concrete S.L. assisted the project phase of the architect for this building, and to the precaster for moulds, prototypes and serial manufacturing of this architectural concrete.