Effects of alkaline and alkaline-earth ions on the rheological behavior and zetametric study of two cement pastes (artificial cement portland-CEMI and cement resistant to the sulfates-CRS) with the polynaphthalene sulfonate (PNS)

摘要

The use of admixtures which tends to be generalized in the formulation of self-compacting concrete (SCC), requires taking into account the chemical co mposition of cement, particularly its content of SO 3 , which can inhibit or restrain the effect of these a dmixtures (superplasticizers). For more information of the compatibility problem of cement-superplasticize r, the rheological tests with a rheometer-AR2000 and measurements of zeta potential with a Zêtasiser -2000 were used in this study. In order to understand this phenomenon due to the presence of S O 3 in cement, we propose to evaluate the action of alkaline and alkaline-earth ions, incorporating different types of additions (K + , Na + , and Ca 2+ ) to the cement pastes. To achieve this, our work will conce rn the study of rheological properties and physical characteristics of the pastes obtained using two ty pes of cement (C1: Cement Resistant to the Sulfates (CRS) and C2: CEMI). This experiment will focus on two reports: Water/Cement ( W/C) = 0.30 for which the polynaphthalene sulfonate (PNS) is used as supe rplasticizer and W/C = 0.50 (without superplasticizer). The results show that the presen ce of sulfate leads to different rheological behavi ors which are function of sulfates and the cements used