Effect of the clinker composition on the threshold limits for Cu, Sn or Zn

The threshold limit corresponds to the maximum amount of trace element that could be incorporated into clinker whilst reaching the limit of solid solution of its four major phases (C3S, C2S, C3A and C4AF). For Cu, Zn or Sn, these threshold limits in a standard clinker (65% C3S, 18% C2S, 8% C3A and 8% C4AF) were equal to 0.35, 0.7 and 1 wt.% respectively (Gineys et al., in press). This paper presents the effect of the clinker composition on these threshold limits. Laboratory made clinkers having different mineralogical compositions was characterised by XRD and SEM. Results showed that the threshold limits for Cu, Zn or Sn were consistent. The threshold limit for Sn was affected by the Bogue content in interstitial phases. On the other hand, the threshold limit for Zn was affected by the Bogue content in C3S of clinker while that of Cu was unaffected by any modifications of clinker composition.