Speed hardening system improves tunnel construction

BASF claims that its latest innovation will help improve efficiency in tunnel construction operations. Developed by BASF's Construction Chemicals division the new Crystal Speed Hardening system (CSH) is an advanced admixture technology aimed directly at the tunneling market.
February 14, 2012 Read time: 2 mins
The new concrete concept from BASF will help cut curing times
2645 BASF claims that its latest innovation will help improve efficiency in tunnel construction operations. Developed by BASF's Construction Chemicals division the new Crystal Speed Hardening system (CSH) is an advanced admixture technology aimed directly at the tunneling market. This product offers increases in efficiency for concrete casting, both for precast segments and cast in-situ linings. The fast-curing concept allows the removal of formwork at an earlier stage of the casting process and increases productivity. The product can shorten the length of time that formwork or shuttering has to be kept in position or by reducing the number of sets of formwork required. In addition to supporting efficiency, the system helps reduce CO2 emissions, optimises material use and meets high quality specifications according to the firm. It does so by providing high early strength development whilst balancing the requirement for an optimum mix through the use of more binding material and reduced clinker content.

The CSH concept uses a new hardening accelerator, X-SEED, to boost early strength development by modifying the action mechanism of cement hydration. X-SEED is made of suspended CSH-seeding crystals: the material added is of the same nature as the final hydration products from the cement reaction with water. As the suspended crystals are considerably smaller than microsilicas, the surface is much more beneficial for accelerating the crystal growth during the early stages of concrete hardening. The product has already been tried and tested in a number of tunneling trials. The abbreviation CSH also refers to calcium silicate hydrates; the cement hydration products responsible for the compressive strength of concrete. Hydration speed depends on the chemical composition of clinker and other cementitious materials. To simplify the science, by using BASF's X-SEED admixtures, a liquid suspension of synthetic crystal seeds on the nano scale, the growth of calcium silicate hydrate crystals is significantly accelerated.

Road Structures

For more information on companies in this article

Related Content

  • Advanced road recycling with Wirtgen
    November 4, 2019
    Wirtgen has developed its high-performance W 380 CRi cold recycler to meet requirements for roads requiring structural rehabilitation. This innovative machine is said to highly productive, allowing it to carry out structural road rehabilitation more quickly and with greater cost-effectiveness and quality than previous equipment.
    Read More
  • Finnish research body highlights hydrogen as future fuel
    May 7, 2013
    The Finnish VTT research body believes that hydrogen offers considerable potential as a future fuel, according to its latest study. The Finnish hydrogen roadmap has been compiled by VTT Technical Research Centre of Finland and partly funded by the Finnish Funding Agency for Technology and Innovation (Tekes). According to VTT’s study, hydrogen fuelled vehicles will be as important as electric/battery types in minimising traffic pollution. The study says that transport applications for hydrogen are now close
    Read More
  • ADT market developments
    May 25, 2016
    The market for ADTs has developed considerably in the last 20 years while the number of manufacturers active in this segment has also grown Volvo CE was a pioneer of the ADT; the first firm to mass manufacture an articulating, tipper truck with all-wheel-drive in the 1960s, although it is not correct to say that the firm actually invented the ADT as some may claim. Performance has increased considerably in the ADT sector in recent years, with many trucks now featuring low maintenance, oil-immersed d
    Read More
  • A breakthrough in the horizontal reuse of PA (porous asphalt)
    May 12, 2016
    An ambitious objective has led to significant steps in the reuse of PA (porous asphalt). While the market incidentally produces PA with a maximum of 30% of recovered raw materials, BAM has introduced its own innovations, enabling more than 90% of raw materials to be reused. And this year, subsidies from the European Commission will enable the LE2AP demonstration project to be constructed: one kilometre of sustainable PA. Large-scale production is also being developed.
    Read More

Highlighted Content