PRECAST WALLING IS THE SAFEST OPTION

Precast walling is facing fierce opposition from new steel fencing systems that create a tough barrier, as well as providing occupants with almost unhindered views. While these fencing systems provide buyers with far greater choices, they are not suitable for every application and, in most instances, simply cannot provide the same level of security that is offered by a solid concrete barrier.

Melinda Esterhuizen, operations and marketing director of Echo, a preeminent supplier of hollow-core precast concrete walling, says that while some suppliers market the fencing as being as effective as concrete walling, it actually is not.

No comparison “Where security is a priority, fencing simply can’t be compared with a 50MPa 150mm (thick ) prestressed precast concrete wall. It provides both a visual and physical barrier that prevents wouldbe intruders from scoping the premises, as well as being able to withstand extreme punishment.

“ I t ’s i m p o r t a n t t h a t p e o p l e under st and the di f f er enc e . S t e el fences are largely used in residential or light industrial systems for low- to medium-security applications – unless they’re supported by supplementary measures such as guards or control room-linked cameras. Our hollow-core concrete walls are used in high-security applications and provide barriers to protect anything from military bases, airports, telecoms, petrochemical and gold refineries to providing barriers to

separate pedestrians and traffic from railways and highways.

“Due to their smooth surface, the walls can’t be climbed and the highstr ength r ein f or ced concr ete will withstand hammer blows and even vehicles being driven into it at speed. Since they’re up to 6m high, specialised equipment would be needed to either climb or penetrate the walls – and that would take time and involve a considerable amount of noise and effort.

“Considering that one precast panel can be 5-6m long, 1,2m high and weigh about three tons, it can’t be manhandled and anyone wanting to smash their way through it would have to contend with two rows of 5mm triple-indented prestressed wire that can’t simply be bent or cut,” says Esterhuizen.

Maintenance-free She adds that a precast wall is a lifetime investment and does not require maintenance once erected, provided it is properly installed and founded. This is an important consideration wherever conditions conductive of corrosion exist, such as coastal areas, certain industrial

plants, marshy areas, etc, where fences would probably eventually corrode.

Precast walling systems in all shapes and forms o f fer versatile solutions that can last a lifetime. By its nature, concrete is robust and strong, which adds an element of security that cannot be matched . E cho’s high -security prestressed hollow-core walling system provides rapid deployment and can secure even the highest-risk areas, which is a tougher act than any fence can follow.

(Above and left): Precast walling systems.

Benefits of precast walling systems: - Rapid installation. - Wall heights are up to 6m. - Super-strong. - Effective barrier traffic and sound - Restricts visibility. - Lifetime investment. - Suitable for industrial and some residential estate applications.

(Below): An aerial view of the University of Pretoria’s impressive new Engineering 4.0 building.

The University of Pretoria will become the env y o f academics around the world when its ultra-modern national material reference laboratory, including an impressive concrete laboratory, is completed later this year.

Engineering 4.0 is the fourth major engineering building on the university’s premises and will serve as a research centre for materials used in the roadbuilding and construction industries. The facility will also facilitate specific commercial testing for extreme or difficult testing, especially where other laboratories do not have the required facilities. According to Prof Wynand Steyn, head of the Department of Civil Engineering at the university, the decision to construct the facility follows talks with the SA National Roads Agency Ltd (Sanral) over the requirement for a roads reference laboratory. Because the experimental area is situated between the university and the Council for Scientific & Industrial Research premises, an agreement was signed between these parties to cooperate in its development.

Multi-purpose facility He adds that when completed, it will be the largest facility of its type in SA and

WORLD-CLASS ACADEMIC LABORATORY NEARS COMPLETION

one of the largest in the academic world. The facilities and equipment will have “extraordinary” capabilities, including extreme temperatures and conditions, which will give the university’s postgraduate students the opportunity to undertake focused and advanced research. It will also give trained engineers valuable exposure to material tests in controlled laboratory environments and provide suitable facilities to conduct duplicate testing for Sanral, as well as other local and international institutions. Facilities for the training of concrete technologist are also on the cards.

The concrete laboratory takes up a large part (5 500m² of the total 8 000m²) of the new building and will be fully equipped to handle under- and postgraduate students with a preparation area, standard concrete testing apparatus, controlled curing facilities with four specialised curing rooms from 5-85˚C and 85-100˚C humidity and other equipment.

Special floor “We’ve constructed a 1m-thick strong floor spanning 20m x 15m with precisely spaced connection points every halfmetre. This will allow for different configurations of jacks and other gear and give space for multiple projects to be accommodated simultaneously,” says Steyn. “The facility will be a major benefit for our students, partners and the concrete industry as a whole. It will generate knowledge for the benefit of the entire civils community and when it opens its doors on 1 March, it will allow co-operative research between disciplines and other civils laboratories and will be part of the exciting Innovation Africa initiative.”

“The facilities and equipment will have extraordinary capabilities, including extreme temperatures and conditions.”