BASF promotes new-age concrete concept
BASF’s construction chemicals division has recently introduced a new-generation concrete concept, which combines the benefits of traditionally-vibrated concrete with those of self-compacting concrete.
Known as the Smart Dynamic Construction (SDC) concept, it has been developed in response to the new challenges for construction chemicals created by constantly changing construction techniques.
These challenges include the need for energy efficiency, higher concrete durability through perfect covering of reinforcement and higher fluid concretes to save time and money, according to Drummond Welsh, business systems manager for Admixture Systems, BASF Construction Chemicals.
The SDC concept allows the readymix concrete industry to reach these goals, he adds.
“As part of ongoing research over the past three years, BASF has been working on a solution to combine the advantages of traditional vibrated and self-compacting concretes, based on the notion that S5 concrete is not fluid enough and self-compacting concrete is not stable and reliable enough,” Welsh explains.
The result is the SDC concept suitable for upgrading S4 and S5 concretes to a higher performance level, with self-compacting characteristics and the same ease of production as standard concrete, at minimum extra cost. This new-generation concrete is easy to produce and robust in everyday use.
“The SDC concept consists of a mix design with less than 380 kg of fines; a tailor-made Glenium superplasticiser with exceptional workability retention and a low water to cement ratio; and the new RheoMatrix product – a viscosity-modifying agent (VMA) with self-organising molecules as the key element. Concrete mix designs can now be optimised to achieve unmatched and unique performance levels,” says Welsh.
VMAs are chemicals of natural origin or engineered purposely to modify yield stresses and/or plastic viscosity. They stabilise unstable concrete, significantly increasing the yield stress, with much lower increase of plastic viscosity. “Improvement of the yield stress of concrete is not enough to stabilise it; it is necessary to increase plastic viscosity at the same time. Combining the two effects, stability is improved to such an extent that the quantity of fines can be reduced,” he says.
“RheoMatrix 100 consists of a mixture of water-soluble polymers, which modifies the rheological properties of concrete. Its tailored mode of action imparts a level of viscosity within the concrete, enabling the correct balance between fluidity, passing ability and resistance to segregation – apparently opposing properties – to be achieved. This balance is lacking when the fluidity of the concrete is obtained by adding water,” Welsh points out.
Features & benefits
This innovative concept meets the existing and continually increasing demand for more fluid concretes and offers the following features and benefits to the industry without affecting flowability or strength development:
• Robust mix design with less than 380 kg of fines and day-to-day raw material;
• Slump flow between 600 and 700 mm;
• Strength C20 to C35;
• Self-compacting characteristics;
• Prevents segregation and bleeding;
• Can be used with all types of cement;
• Does not affect setting time; and
• Less sensitive to changes in water demand.
Welsh continues: “Thanks to a unique mechanism of action in concrete, savings of fines (less than 0.125 mm) can be achieved. The stable and highly-fluid concrete is close to self-levelling and thus permits installation without subsequent compaction. The placing process is easy enough to be handled by just one operator, which additionally saves up to 40 per cent of work time. This increases placing productivity up to five times. This apart, it is as easy to produce as standard concrete because the mixes are less sensitive to changes in water demand.
“In addition, the low percentage of fines such as cement – the production of which causes carbon dioxide emissions – improves the ecological efficiency of the concrete. Furthermore, this highly-fluid concrete embeds the reinforcement perfectly, giving it optimum protection against external corrosion. This characteristic increases the durability of the concrete and as a result considerably extends the lifespan of structures.
“And, due to its self-compacting characteristics, this concrete does not need to be vibrated, which means no noise and no health-hazardous vibrations for workers. Additionally, the new design guarantees a type of concrete with low stickiness, thus improving its workability.”
Application
RheoMatrix 100 is recommended whenever an increase in mix viscosity would be advantageous, especially for self-compacting concrete with low fines content (material passing the 0.125 mm sieve).
It is a ready-to-use liquid admixture, which should be added to the concrete during the mixing process together with the water. “This is particularly important in order to obtain maximum efficiency. For best performance, it is advisable to continue mixing until the concrete is completely homogeneous,” he emphasises.
In summary, the SDC concept provides a technology to simplify the production and control of a dynamic concrete, which adds economical, ecological and ergonomic values.
“It underlines the commitment of BASF’s construction chemicals division to tailor-made solutions that drive the concrete industry forward. In combination with local technical support and the backing of one of the world’s leading chemical companies, this new concept has the potential to move the market up to the next level of advanced construction practice,” concludes Welsh.
BASF’s construction chemicals division has recently introduced a new-generation concrete concept, which combines the benefits of traditionally-vibrated concrete with those of self-compacting concrete.
Known as the Smart Dynamic Construction (SDC) concept, it has been developed in response to the new challenges for construction chemicals created by constantly changing construction techniques.
These challenges include the need for energy efficiency, higher concrete durability through perfect covering of reinforcement and higher fluid concretes to save time and money, according to Drummond Welsh, business systems manager for Admixture Systems, BASF Construction Chemicals.
The SDC concept allows the readymix concrete industry to reach these goals, he adds.
“As part of ongoing research over the past three years, BASF has been working on a solution to combine the advantages of traditional vibrated and self-compacting concretes, based on the notion that S5 concrete is not fluid enough and self-compacting concrete is not stable and reliable enough,” Welsh explains.
The result is the SDC concept suitable for upgrading S4 and S5 concretes to a higher performance level, with self-compacting characteristics and the same ease of production as standard concrete, at minimum extra cost. This new-generation concrete is easy to produce and robust in everyday use.
“The SDC concept consists of a mix design with less than 380 kg of fines; a tailor-made Glenium superplasticiser with exceptional workability retention and a low water to cement ratio; and the new RheoMatrix product – a viscosity-modifying agent (VMA) with self-organising molecules as the key element. Concrete mix designs can now be optimised to achieve unmatched and unique performance levels,” says Welsh.
VMAs are chemicals of natural origin or engineered purposely to modify yield stresses and/or plastic viscosity. They stabilise unstable concrete, significantly increasing the yield stress, with much lower increase of plastic viscosity. “Improvement of the yield stress of concrete is not enough to stabilise it; it is necessary to increase plastic viscosity at the same time. Combining the two effects, stability is improved to such an extent that the quantity of fines can be reduced,” he says.
“RheoMatrix 100 consists of a mixture of water-soluble polymers, which modifies the rheological properties of concrete. Its tailored mode of action imparts a level of viscosity within the concrete, enabling the correct balance between fluidity, passing ability and resistance to segregation – apparently opposing properties – to be achieved. This balance is lacking when the fluidity of the concrete is obtained by adding water,” Welsh points out.
Features & benefits
This innovative concept meets the existing and continually increasing demand for more fluid concretes and offers the following features and benefits to the industry without affecting flowability or strength development:
• Robust mix design with less than 380 kg of fines and day-to-day raw material;
• Slump flow between 600 and 700 mm;
• Strength C20 to C35;
• Self-compacting characteristics;
• Prevents segregation and bleeding;
• Can be used with all types of cement;
• Does not affect setting time; and
• Less sensitive to changes in water demand.
Welsh continues: “Thanks to a unique mechanism of action in concrete, savings of fines (less than 0.125 mm) can be achieved. The stable and highly-fluid concrete is close to self-levelling and thus permits installation without subsequent compaction. The placing process is easy enough to be handled by just one operator, which additionally saves up to 40 per cent of work time. This increases placing productivity up to five times. This apart, it is as easy to produce as standard concrete because the mixes are less sensitive to changes in water demand.
“In addition, the low percentage of fines such as cement – the production of which causes carbon dioxide emissions – improves the ecological efficiency of the concrete. Furthermore, this highly-fluid concrete embeds the reinforcement perfectly, giving it optimum protection against external corrosion. This characteristic increases the durability of the concrete and as a result considerably extends the lifespan of structures.
“And, due to its self-compacting characteristics, this concrete does not need to be vibrated, which means no noise and no health-hazardous vibrations for workers. Additionally, the new design guarantees a type of concrete with low stickiness, thus improving its workability.”
Application
RheoMatrix 100 is recommended whenever an increase in mix viscosity would be advantageous, especially for self-compacting concrete with low fines content (material passing the 0.125 mm sieve).
It is a ready-to-use liquid admixture, which should be added to the concrete during the mixing process together with the water. “This is particularly important in order to obtain maximum efficiency. For best performance, it is advisable to continue mixing until the concrete is completely homogeneous,” he emphasises.
In summary, the SDC concept provides a technology to simplify the production and control of a dynamic concrete, which adds economical, ecological and ergonomic values.
“It underlines the commitment of BASF’s construction chemicals division to tailor-made solutions that drive the concrete industry forward. In combination with local technical support and the backing of one of the world’s leading chemical companies, this new concept has the potential to move the market up to the next level of advanced construction practice,” concludes Welsh.
Gulf construction
