Popis: |
The effects of four pulverised fuel ashes (PFA) and three ground blastfurnace slags (GBFS) on the alkalinity of the pore solution phase of hardened cement pastes has been studied. It has been found that the total alkali content of a PFA is an important factor, but not the only one, determining its effectiveness in reducing the hydroxyl ion concentration of the pore solution. For GBFS, however, there was found to be no direct correlation between the total alkali content of the slag and the composition of the pore solution. Implications regarding the roles of PFA and GBFS in reducing expansion associated with alkali silica reaction (ASR) are discussed. |