Self-Compacting Concrete - the substance of future dreams


Self-Compacting Concrete - the substance of future dreams

The use of Self-Compacting Concrete (SCC) in the precast industry is gaining an increasing amount of attention due to the many benefits that may be gained from its properties.These affect product quality, the working environment, architectural design possibilities, and overall economics.

SCC is a concrete mixture that includes water-reducing admixtures that significantly increase the workability and fluidity of the material. As a result, it flows quickly into place, fills every corner of a mold and allows perfect compacting around the densely located reinforcement. This feature also eliminates the need to vibrate the concrete to reach the desired strength and durability, thus doing away with the noise from electrical compacting equipment. As frosting on the cake, the surface is smooth and free of pores, needing no repair or additional rubbing. The Consolis Group started research on SCC some 10 years ago at their R&D Central laboratory in Parainen on the southern coast of Finland. They applied different new-generation super-plasticizers and, once they became familiar with the practical principles on mixing and casting SCC on a lab-scale, they moved on to Consolis' factories to try and find the best applications. Today, SCC is regularly used at several Consolis-factories, mainly for the manufacturing of beams, columns, and walls. Annually, the self-compacting concrete is used for approximately 20 percent of all products (excluding hollow-core slabs) and is increasing continuously.

Improved ergonomics and operational safety

The benefits of SCC are numerous. Because it flows so smoothly, it can be poured quickly, which means less work and a faster casting cycle. The more complex the element, the greater the advantage gained. Improved ergonomics and operational safety make the working environment more comfortable and more attractive to young people considering a job in the industry. The longer life cycle for mold surface materials means less waste from the used molds and less cleaning up of tools, equipment, and surroundings.

Doing away with noise

Strängbetong AB in Kungsör, Sweden, is a Consolis-company. Since a few years back they use solely SCC in their production of wall elements and TT-beams. "Although the material costs for SCC are higher than for normal concrete, the savings in labor are so significant that the total costs are substantially lower when using SCC", says Mr. Allan Myllyvainio, Factory Manager at Strängbetong AB. "In addition, the material prices are steadiliy cheapening". Already back in 1986, Strängbetong began replacing their old hollow-core slab production machines with silent Elematic Extruders, considerably dropping the noise level of the working area. "That was a great improvement, but now that we are also using SCC, which requires no vibrating, we have completely done away with noise at our factory in Kungsör", says Mr. Myllyvainio. "This comfort factor has made it easier for us to recruit new personnel".

Old equipment in a new light with SCC

At Spenncon AS in Hönefoss, Norway, another Consolis factory, they are also using SCC in part of their production of wall elements. Says Production Manager Mr. Magnar Dammen: "We have been casting walls with SCC for about four years now, and are very pleased with the quality of the final product". "This concrete dries quicker, the surface is smoother, and it is much easier to make openings for doors and windows". "In the old days, we used vibrators on the molds to compact the concrete, but the noise was terrible, and so we stopped using these otherwise perfectly good battery molds", says Mr. Dammen. "But with SCC, we could start using them again, and we are in fact considering more Elematic battery molds to increase production".

Designing future dreams

In the words of Mr. Klaus Juvas, Manager of Laboratory of Materials Technology at Consolis: "To assure the final success and breakthrough of SCC, the precast industry designers and material suppliers should use their imagination to find new products, new production methods, and the best materials for SCC". "The use of SCC is a real step forward in terms of modern concrete technology, and the volumes of products made with SCC will certainly continue to increase in the future".