| Research Abstract |
The achievements obtained in this study are divided into the four themes of ASR suppression mechanisms of mineral admixtures, irples of Ca(OH)2 in ASR gel composition, effects of lithium salts on ASR gel compositions and ASR in ultra-high strength concrete. The items revealed in each theme are summarizedas follows ;
(1) ASR gels were found to be produced even in fly ash-containing mortars showing no expansion.
(2) Iri blastfurnaceTContaining jmprtars, reductions in/OH^- ion concentration are not so great, and the suppression of ASR expansion in the mortars is due to the reduction in the mobility of ions and pore solution through the cement paste phase.
(3) In silica fume-containing mortars, the suppression of ASR expansion is, brought about by great reductions in OH^- ion concentration in, the pore solution.
(4)The pore solution intnided into fissures in the cacined flint aggregate particles in mortars, and then ASR occurred along silica surfaces in the fissures.
(5)The composition of ASR gels was homogenized by the addition of lithium salts. However, the homogenization in the ASR gels may not directly be related to the suppression of ASR.
(6) In mortars with, an extremely low water : cement ratio, ASR gels produced within reactive aggregate particles could not permeate into the cement paste, and were accumulated in cracks within the cement paste.
|
