Tag Archives: Chryso Southern Africa

CONCRETE WIND TURBINE TOWERS GET CHRYSO TREATMENT

In wind farms all over South Africa’s Eastern Cape and Western Cape provinces, CHRYSO Southern Africa is adding value to the precast concrete segments used to construct the 100 metre tall wind turbine towers.

The average concrete turbine tower comprises 18 precast segments, each with a height of between 18 to 20 metres and a diameter of between 600 mm and two metres. In the manufacture of these precast elements, the production speed and segment uniformity are essential. This demands high early strengths to ensure fast erection, while giving the towers an ability to withstand demanding fatigue loads. Wind turbines must also be able to perform in some of the country’s harshest working environments, making durability a key requirement for the concrete mixes used in precast units.

The CHRYSO® Fluid Premia range of plasticizers facilitates workability retention of between 30 and 45 minutes while achieving high early strengths. These early strengths allow for the fast erection of the towers owing to the quick turnaround time as the mould release and pre-stressing release can be done earlier. optimises early and late age strength development in concrete mixes.

The CHRYSO® Fluid Premia range maintains consistency in the manufacturing of reinforced concrete components, reducing the sensitivity of concrete to variations in water content.

Plastic shrinkage cracking and plastic settlement cracking can occasionally penetrate deep into a precast unit, causing significant cost in remedial measures and even replacement. Applying a curing compound from the CHRYSO® Cure Range to the precast segments reduces the incidence of shrinkage cracks and promotes better strength gain characteristics. Curing compounds also increase the impermeability of concrete, making it more durable.

Another important product gaining traction in this market is a.b.e.® duragrout. Developed especially for wind farm precast applications, this product which is proving popular is being used to level segment holders. The duragrout WF product is used for grouting and bedding of structural elements; it can be pumpable or gravity fed and has good cohesive properties without bleed or segregation. It is pre-blended and ready-to-use, requiring only clean water to be added.

In a related development, CHRYSO has partnered with Maturix to develop an innovative sensor solution with a digital cloud platform to monitor the maturity of concrete. It has been used worldwide on more than 350 in-situ and precast projects, and is being trialled on a wind farm project in South Africa. This cloud-based solution helps the construction industry to monitor concrete curing and hardening through hydration temperature measurements.

CHRYSO SOUTHERN AFRICA LEADS WITH FIBRE SOLUTIONS

CHRYSO Southern Africa offers outstanding solutions when it comes to fibre reinforced concrete. A mutually beneficial partnership with Oxyfibre has resulted in world class products being available locally, supported by expert fibre technology development and consultancy capabilities. 

Izak Louw, general manager at Oxyfibre, says that CHRYSO’s presence and established infrastructure in Southern Africa made them the partner of choice for making Adfil fibres available in Southern Africa.

CHRYSO® EasyFinish, as a macro fibre, optimises speed of construction by eliminating the need for costly placement of rebar and ensuring adequate cover to reinforcement. Added benefits include smooth surface finishes, maximum bond, greater tensile strength per fibre for enhanced residual flexural strength and toughness in the concrete. 

For micro fibre applications, CHRYSO® Fibrin XTserves as alternative to crack control mesh. The use of micro fibres in concrete product manufacturing has proved to enhance the surface properties and durability, significantly reducing the occurrence of plastic shrinkage and plastic settlement cracking.

Recent projects where these fibres have been used include the placing of 7000 m2 of concrete in very thick surface beds and several large warehouse floors. Other applications have been in coastal defence structures and shotcrete in the Western Cape, as well as for the construction of floors in the farming and food processing industries where harsh chemicals and other deleterious substances could potentially affect the concrete. All these projects reported noticeable cost and time savings. 

Louw says that ongoing research has resulted in new fibre solutions that will be available shortly. These include Ignis, a micro fibre specifically designed for its fire protection benefits, and a macro fibre that will address problem areas in the precast industry.

Fibre technology is used extensively in readymix concrete, but the ease of transport, storage and handling of these fibres also makes them ideal for smaller projects and on-site mixing.

The CHRYSO Southern Africa / Oxyfibre partnership has created a win-win solution for all stakeholders providing concrete reinforcement solutions for construction projects to be undertaken safely and rapidly with reduced waste and reduced impact on the environment.

CHRYSO DECO WASH PICO GIVES THE PERFECT SANDED FINISH

CHRYSO Southern Africa offers a comprehensive range of products to optimise the placing, performance and aesthetics of concrete. Particularly in the field of decorative concrete, CHRYSO has become a leader in addressing the need for quality, durable and inspiring surfaces and finishes. 

One such a product is CHRYSO® Deco Wash Pico, a surface retarder that lightly delays the setting of the concrete surface layer. Following the correct application and washing-off procedures will result in a finished look of a “sanded” or “acid washed” surface.

Before application, all surrounding supports and elements for which the product is not intended must be covered. No bleed water must be visible on the concrete surface and troweling and smoothing should have been completed. After thoroughly mixing the product, it is sprayed uniformly onto the surface of the fresh concrete. This water-based solution forms a thin film that is resistant to fine rain and high temperatures.

Depending on weather conditions, the product should be washed off with a high-pressure washer within 24 hours to reveal the surface effect. For a better homogeneity and detail, a preliminary brushing with a single nylon brush machine is advised. To ensure a uniform appearance, it is important to keep to the same washing-off time for all parts of the project on a given site. Time windows may vary in case of significant temperature variations.

CHRYSO® Deco Wash Pico is suitable for use on walkways, pool surrounds, patios, and areas open to public pedestrian traffic. 

CHRYSO Southern Africa’s sales and technical teams are on hand to discuss how CHRYSO® Deco Wash Pico can add aesthetic appeal to a concrete surface.

CHRYSO® DEM RANGE PLAYS CRUCIAL ROLE IN FORMWORK

CHRYSO Southern Africa’s commitment to provide quality solutions for the built environment, is evident in the CHRYSO® DEM range of application driven release agents.

Understanding the crucial role formwork plays in the production of quality concrete and similarly moulds in the manufacture of precast elements, the CHRYSO® DEM range has introduced much needed flexibility to the industry. Previously, it had been a case of one-size-fits-all when it came to release agents.

Discerning clients, developers, manufacturers and specifiers are increasingly particular about the aesthetics of concrete finishes. To achieve the desired texture and colour finish on the concrete’s surface it is imperative that formwork surfaces are adequately prepared in terms of cleanliness and that an optimal release agent is selected for the application.

As different form-face materials have varying longevity, absorbency and texture characteristics, specialised release agents are required to realise the full aesthetic potential of the formwork, eliminating wastage of time and materials.  

Not only will the optimal release agent reduce the likelihood of imperfections and surface defects (particularly blow holes) in the concrete, when applied correctly it will also ensure no staining or deviation from the specified colour finish.

The top quality release agents in the CHRYSO® DEM range provide greater coverage, are easy to use and add consistent quality, which is important on construction sites as well as in precast plants.

CHRYSO®Dem Bio 10 is a vegetable-based, bio-degradable and non-toxic release agent, which will not pollute the environment. It has a low odour and is therefore safe to use in confined spaces such as mining, tunneling and any poorly ventilated areas. It is suitable for use with all types of formwork: metal, wood, plastic, polystyrene and fibreglass.

Another product in the range is Elio VP, a hydrocarbon oil-based agent, which is suitable when producing concrete pipes with roller compacted pipe technology. The Elio VP significantly reduces surface defects. The low viscosity oil creates less surface tension against the sides of the pipe steel moulds which results in less outer concrete surface damage when demoulding.

CHRYSO® Dem Oleo WB is a wax-based delayed-release agent for wooden formwork used on conventional jobsites and for wooden pallets for cement-based brick manufacturing. This release agent temporarily protects and extends the life of veneer laminated shutter boards, decreasing the frequency of re-lamination. This release agent can also be used to coat pallets for protection, when stacking cement-based bricks on them.

CHRYSO® Dem Oleo FW is a hydrocarbon based, which is suitable for use with all types of formwork. It is however not suitable for precast applications. It ensures ease of formwork release and also temporarily protects and extends the life of metallic formwork from corrosion.

CHRYSO® DEM Oleo SM is a mineral-based delayed-release agent, ideal for use with metallic or wooden formwork for wet precast. It does not stain or affect the colour of the concrete when applied correctly. It is the perfect solution when white cement is used for specialised architectural finishes. CHRYSO® Dem Oleo SM can handle the high temperatures of steam curing and provides rust prevention. This release agent is a hydrocarbon oil-based delayed release agent, used for steam cured precast elements cast in steel formwork.

CHRYSO® Dem Oleo RT is a hydrocarbon oil-based, delayed-release agent for the roof tile industry, developed specifically for use with aluminum roof tile pallets.

This ready to use range of release agents reduces the likelihood of errors, which may occur in other release agents, where mixing of various components is required.

When applied correctly and for the specific purpose, the CHRYSO® Dem range does not modify cement hydration and as it is water repellent, it is not affected by rain.

These products are manufactured locally by CHRYSO Southern Africa at its production plant based in Jet Park, Johannesburg and comply with regulations for the transport and disposal of hazardous materials.

While generally regarded as a minor item on the bill of quantities, the specification and selection of an appropriate release agent and application method may prove to be critical to the success of the project, affecting both the quality and colour of the surface finish. A release agent is a low-cost item, yet vital in relation to the cost of formwork and moulds. It thus makes sense to use the appropriate release agent for the correct application and formwork substrate, in order to protect and extend the life of the formwork or mould, ultimately resulting in financial benefits.

As each release agent contributes differently to the off-form finish, care in the selection of the release agent is critical.

CHRYSO Southern Africa’s sales and technical teams are on hand to discuss the correct CHRYSO® DEM solution for any application, condition or aesthetic specification.

REFURBISH OLD CONCRETE SURFACE EASILY WITH TEXTURE TOP®

Texture Top® offers the ultimate decorative solution to save money and time by refurbishing old concrete surfaces.

Ageing, worn or surface damaged concrete no longer has to be demolished and recast at a cost to the customer and the environment. Instead, Texture Top®, a CHRYSO Southern Africa product, can be used to enhance existing surfaces through renovation and repair.

Texture Top® is a polymer-modified cementitious coating which could be applied either with a spray gun or trowel to obtain a specified finish. The spray technique allows coverage of large surfaces in a short time.

At an application thickness of merely 2 mm, this thin anti-slip coating offers excellent mechanical resistance. The product is available in a standard range of colours, and could be custom pigmented to complement various finishes.

Texture Top® can be applied to achieve any textured or smooth finish. This is a simple and durable solution to renovate and add aesthetic value to surfaces around swimming pools, paths, terraces, driveways, patios, floors and stairs, as well as interior and exterior walls.

CHRYSO Southern Africa’s technical and sales teams provide leading edge expertise in support of Texture Top® which makes it easy to achieve customised modern and trendy decorative finishes in a cost-effective and environmentally responsible way.

CHRYSO VERTICART CARVES A PLACE AT THE LEONARDO

CHRYSO, a global specialist in the chemistry of building materials, supplied its innovative VerticArt to The Trinity Session for an iconic artistic creation in the foyer of The Leonardo in Sandton.

VerticArt was the material of choice when The Trinity Session, a creative production team, embarked on the curation of a sculpted representation of a cross-section through earth, showing the strata formed by tectonic plates shifting and colliding, to form the intricate patterns of geological formations.

Marcus Neustetter, a director of The Trinity Session, explains that this ambitious project called for an earthy, robust medium. CHRYSO VerticArt, a cementitious mortar which is designed for application to vertical surfaces, presented the ideal material.

The chemical makeup of VerticArt allows for a vertically applied maximum thickness of 150 mm, making it ideal for relief three-dimensional (3-D) artwork.

CHYRSO VerticArt was applied in various thicknesses and then carved and textured using palette knives, trowels, chisels, straight edges and wire brushes, to the exact creative brief. A zero to 48 hour carving window ensured that the artists had sufficient time to perfect the application and sculpting processes necessary to create the required 3-D effect.

The mural was intentionally not pigmented, resulting in a very realistic artistic rendition of a cross-
section through the crust of the earth. This is further enhanced with focused lighting, giving the effect of an upwards journey though geological eons as visitors ascend the staircase.

This project used 4,5 tonnes of CHRYSO VerticArt, covering 140 m2, scaling a height of 15 metres (three storeys). It required the specialised skills of eight individual artists, in conjunction with the CHRYSO
technical team and took seven weeks to complete.

The scale, innovative material, product methodology and conceptual approach ensured that the
programme was not just a financial prospect for the materials supplier and the artistic curating team, but rather an opportunity for upliftment and growth for many of the artists, including emerging creative talent.

The artists, Damien Grivas (team leader), Angelique Koekemoer, Ciara Struwig, Marlecia Marais, Patrick Rapai, Paul Setate and Zanre Van Der Walt brought their own technical and creative touch to realising the vision of this work.

Neville Wearne, CHRYSO Southern Africa’s project manager: concrete aesthetics, says that VerticArt was developed to allow artists to create reliefs and textures, which can be sculpted and carved.

“This massive and bold statement artwork is a first for CHRYSO’s VerticArt in both South Africa and worldwide, challenging architects, designers and artists to further explore the decorative potential of concrete,” he concludes.

WORLD CLASS LAB AT CHRYSO PROVIDING SOLUTIONS

Upgrading its Jet Park laboratory has given CHRYSO Southern Africa the capacity to expand its solutions to customers in fields including aggregates, concrete aesthetics and cement.

Staffed by specialist engineers in interface physical chemistry, the CHRYSO Southern Africa laboratory conducts both research and development (R&D) and testing. It also designs its own molecules for industrial-scale production.

“There are a number of challenges facing our customers, including energy costs, environmental regulations and the recently introduced carbon tax,” Mpume Mlalazi, R&D manager at CHRYSO Southern Africa, says. “By enhancing our world class laboratory facility, CHRYSO can develop solutions that mitigate these challenges.”

Among the capabilities of the laboratory is a recently launched sand and clay diagnosis tool (patent pending) for accurate quantification of delirious clay minerals in aggregates, says Mlalazi. This helps customers address the growing issue of problematic aggregates in a cost-effective and environmentally responsible way.

“Our solutions, rheology robustness enhancers and clay enablers, use polymer science to allow customers to make use of readily available aggregates, without having to wash the material extensively with water,” she says. “The environmental benefits of this technology are substantial, especially in water-scarce areas.”

The facility has an extensive colour testing capability to support CHRYSO’s new concrete aesthetic range. Accurate measurement of colour can be conducted, allowing customers to easily match the colours that are required for a particular project. The expansion of technology also means that the laboratory can scientifically test demoulding oils, another important aspect of the company’s offering.

Mlalazi highlights that the laboratory has expanded its expertise into cement testing as well. “As part of our R&D function, we have acquired additional equipment to facilitate testing of cement,” she says. “This can now be done in a pure molecular chemistry environment.”

In addition, micro-concrete evaluation is used to optimise admixture selection to cement performance.

She emphasises that this work has put the company “ahead of the game” in finding energy saving solutions and meeting the impact of carbon tax legislation. The laboratory can assist with testing and R&D related to both extended cement and concrete.

“All work is conducted within stringent standards,” she says. “These include the ISO 9001 quality system, ISO 14001 for environmental protection and ISO 18000 for safety. We also test water quality to ensure we only discharge clean water and recycle water wherever possible.”

CHRYSO Southern Africa’s commitment to R&D is enhanced by research collaborations with local universities. The laboratory also engages graduates from these universities, who are mentored by CHRYSO specialists as part of their professional development.