Evaluation of residual behavior of organic admixture in pore water from hardened cement pastes

Fujita, Hideki*; Haga, Kazuko*; Shibata, Masahito*; Mihara, Morihiro  

The elution behavior of polycarboxylate type superplasticizer from hardened cement pastes were examined by analysis of organic matter in the pore water and curing water. A small quantity of superplasticizer was eluted and a large quantity remained in the solid. Only lower molecular weight matter was detected in the pore water, and decomposition of polymer under high alkalinity environment or selective elution of small molecule were suggested. Though there was the assumption that the effect of primary organic matter in cement like grinding aid was canceled by blank test, the assumption may need to be reconsidered.