Construction World March 2015

PROJECTS AND CONTRACTS

SOLVING DRAINAGE PROBLEM The vast Midrand Estates in Gauteng, which comprises Midstream, Midfield, Midlands and Midstream Hill Estates, boasts not only upmarket residential properties, but also private schools, shopping centres, sports and recreational facilities, fuel stations and churches.

table being exposed in the cuttings, it was imperative that an effective drainage system be installed. This is when Endecon Ubuntu Consulting Engineers proposed that a specific Kaytech geotextile would be the most suitable product for the problem faced. The difficulty in this area is the vast amount of different in-situ soils, ranging from sandy material to black clay and, of most concern at the hospital site, the presence of residual granites and ferric- retes. These sub-soil conditions could result in clogging of drains by means of ferric oxide build-up on conventional woven and nonwoven continuous filament geotextiles, thus a drainage product with larger openings was a necessity. The engineers specified Kaytech’s Geomesh, a dimensioned, PVC-coated, multi-filament woven polyester, designed for soil reinforcement and as a high modulus separator in composite drains. The conventional method of drainage would be to utilise washed river sand dimen- sioned as backfill over slotted pipes. However this sandmay also potentially clog over time and the engineers proposed that a select, suitable geotextile would be the most practical solution for the problem at hand since its installation is similar to that of a conventional sub-soil drain which is more familiar to the site labour. Other factors in this decision were the cost implications of importing washed river sand and that the structure of Geomesh is very similar

Geomesh has larger openings than woven tape to provide non-clogging drainage.

to the retention characteristics of a medium to coarse-grained river sand. The final product consisted of the installation of a conventional shaped drain: 300 mm x 300 mmwith a 110 mm slotted pipe and 19 mm stone all of which was wrapped with 2 500 m 2 of Geomesh. Although it is expected that some fine material will wash through the Geomesh, it will eventually create a natural reverse filter at the interface. The larger openings in Geomesh are known to retain grain sizes of 0,4 – 2 mmwhich will definitely assist to prevent the system from becoming blinded or clogged by the extremely varied sub-soils. It is debatable whether any other upmarket estate in Gauteng can compete with everything that Midrand Estates has to offer the discerning investor and buyer making Kaytech a proud participant in this unique development.

Various in-situ soil types posed a challenge for effective drainage.

To add to all these facilities, a new hospital was constructed on Midstream Hill by main contractor Basil Read. Jodan Construction undertook the earth- works including the installation of the Sub-soil drainage systems. The site for this new Mediclinic Hospital in Midrand Estates has undergone extreme exca- vation operations to accommodate basement parking. With the natural flow of ground water having been altered, resulting in a high water >

32

Stand 47 is an award-winning concept house co-developed by Saint-Gobain, the world’s leading producer of contemporary building technology. The home was built to physically demon- strate the considerable benefits of building with state of the art building materials and systems, rather than with more traditional materials like bricks and mortar. While the public are invited to personally visit and experience the home (situated in Monaghan Farm in northern Johannesburg), this potentially excludes a broader, national audience who are based further afield. Accordingly, the www.stand47.co.za website features an interactive filmed Virtual Tour that gives viewers direct visual exposure to the inside and outside of the house. The tour allows the user to easily move through the home at their own pace and examine information that explains the features and benefits in different parts of the home. Importantly, this ‘first- person view’ is accessible to anybody using any smart device connected to the Internet, without the need for any application download. The site also offers useful insight on how to build a home that is more efficient, comfortable, safer and healthier to live in. The website was produced by The New Order, a design-led multi- disciplinary agency directly involved in developing and building the concept house. VIRTUAL GUIDED TOUR A novel website allows visitors to take a step-by- step guided tour through a physical home using only a cell phone, tablet or desktop computer. >

“The Stand 47 website is a great example of our approach to technology and innovation. We innovate to deliver tangible benefits to consumers. In this case, our digital innovation enables practically any consumer to visit our home and experience aspects of its benefits with the greatest of ease. The new design aims to attract more viewers, to demystify concerns and perceptions about contemporary building methods and to inform those interested to build their own Abode of Awesome,” says Evan Lockhart-Barker, head of marketing at Saint-Gobain South Africa

Says Gavin Rooke, founder of The New Order: “We believe design is the interface between information and understanding. Everything we do is aimed at enabling consumers to understand the benefits of the brands we build. We believe this website achieves exactly that”.

Scan and view the innovative virtual guided tour.

I

CONSTRUCTION WORLD MARCH 2015