• Latest news

    Latest news

  • Latest news

    Latest news

  • Home
  • Blog
  • The fib Symposium “Performance-based approaches for concrete structures” will be held in Cape Town from 21 to 23 November 2016

Structural Concrete, Vol. 8, no. 1, March 2007

Effect of admixtures on fresh grout and two-stage (pre-placed aggregate) concrete

A. Nowek, Gdansk University of Technology, Gdansk, Poland
P. Kaszubski, Gdansk University of Technology, Gdansk, Poland
H.S. Abdelgader, Al-Fateh University, Tripoli, Libya
J. Górski, Gdansk University of Technology, Gdansk, Poland

According to two-stage (pre-placed aggregate) concrete technology, special grout is injected into forms or foundation trenches with aggregate, as backing, placed earlier. The fresh grout differs from the ordinary concrete mixture. Good quality two-stage grout can be prepared in high-speed mixers, for example an Ultramixer (3000 rpm). It is characterised by high fluidity, low sedimentation, good viscosity, intensive hydration and a notable increase in the cement particles' surface. However, because of the unique and complex equipment involved, two-stage concrete technology is still underutilised. The aim of the investigation presented in this work is to design a mixture composition similar in features to Ultramixer grout. For this purpose, the new grout was prepared using a normal mixer (140 rpm) and some admixtures. The experimental tests were performed with different mix proportions. On the basis of the obtained results, an optimal composition has been proposed. A comparison of the new grout features with the properties of the grout produced by the Ultramixer has also been elaborated. The new grout design method can improve two-stage concrete technology. Some preliminary two-stage concrete tests are also presented. 

fib postal address

Case postale 88
CH-1015 Lausanne
Switzerland

Contact

p : +41 21 693 27 47
f : +41 21 693 62 45
e : info@fib-international.org
w : www.fib-international.org

Follow fib

Subscribe our newsletter

 Follow us on
        

Join the fib

Join the fib