Title: Performance of a New Supplementary Cementitious Material in Combination with Chemical Admixtures
Author(s): B. J. Christensen, E S. Ong, and S. D. Somerville
Publication: Symposium Paper
Appears on pages(s): 647-666
Keywords: admixture; brightness; durability; high-range water reducer; pozzolan; silica fume; white
A new type of high-performance, light colored pozzolan (LCP) has been investigated as an alternative supplementary cementitious material. The LCP is a by-product of the production of zirconium oxide from sand, unlike conventional gray silica fume (SF), which is a by-product derived primarily from the silicon metal/ferro-silicon industry. The LCP is predominantly an amorphous silicon dioxide, with minor amounts of zirconium oxide (zirconia) and zirconium silicate (zircon) present. The LCP provides similar strength enhancement and permeability reduction benefits to concrete as SF, without increasing the water demand of fresh concrete, which SF often does. As a result, it does not significantly increase the demand for high-range water reducer (HRWR) as compared to a reference concrete mixture. The LCP is white to off-white in color, which is an advantage as compared to SF when used in architectural, reflective or color-enhanced concrete applications. In addition, the cost of LCP is generally less than that of white silica fume.