Title: Properties of mass concrete con taining an active pozzolan made from clay

Author(s): Miguel N. A. Saad, Walton Pacelli De Andrade and Vladimir A. Paulon

Publication: Concrete International

Volume: 4

Issue: 7

Appears on pages(s): 59-65

Keywords: adiabatic conditions; alkali-aggregate reaction; bleeding (concrete); clay minerals; com-pressive strength; concrete dams; construction costs; drying shrinkage; fineness; kaolin; mass concrete: pozzolan cements; raw materials.

DOI:

Date: 7/1/1982

Abstract:
An active pozzolan is being produced in Brazil at cost approximately one-third that of portland cement. It is made by calcining kaolin clay and then grinding to a fineness of 7000 to 9000 cm2/g. This pozzolan has been used since 1965 as an ingredient in concrete four large dams that required more than 7,000,000 (9,156,000 cu yd) of concrete. Because of the high fineness and activity of the pozzolan, it can be used for cement replacement up to 50 percent by volume, with 90-day compressive strength similar to concrete made with portland ce-ment only. Besides cost savings, use of the pozzolan as a partial replacement for cement in concrete resulted in a lower temperature rise, better plasticity. and effective reduction of expansion due to alkali-silica reaction.*