MECHANICAL PERFORMANCE OF BLENDED TERNARY CEMENTITIOUS SYSTEMS (PORTLAND CEMENT–FLY ASH–BLAST FURNACE SLAG)

Abstract

In this  paper  are  summarized  the results  of  a  research aimed  to  study  the  effect  of  ternary  cementitious  systems  on  the mechanical  properties  of  concrete  in  compression,  modulus  of  elasticity,  Poisson's    ratio  and    modulus  of  rupture.  The experimental program included the test of 120 concrete specimens from 8 mixtures having different dosages of Portland cement,  fly  ash  and  blast  furnace  slag.    The  characterization  of  the  blends  in  hardened  state  was  performed  by  X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The results indicate that blended concretes have the best mechanical properties for same contents of  fly ash and blast furnace slag equivalents to 10%. Also, the mechanical properties of ternary blends mainly depend on the mechanical properties of binary blends. Futhermore it was observed that for ternary  blends, fly ash and blast furnace slag did not show any interaction between their mechanical properties. It is believed that these materials coexist together in the matrix and provide to the concrete an increase in the strength due to the independent reaction of each with the Portland cement.