Formation of ASR gel and the roles of C-S-H and portlandite

Alkali–silica reaction: Kinetics of chemistry of pore solution and calcium hydroxide content in cementitious system

“…Several researchers [10,37,38] found that Na + ions increased the dissolution rate of silica (which consequently increases the rate of ASR reaction). In contrast, other researchers [8,39] reported that the system containing K + ions appears to be reacting faster than the one containing Na + ions. In the current study, it is interesting to note that, as shown in Fig.…”

“…The suggested sequence includes the formation of C-S-H as the first reaction product in the ASR process. The formation of C-S-H continues up to a point of local depletion of Ca(OH) 2 [8][9][10][11][12].…”

“…Recently, several researchers suggested detailed sequence of the ASR gel formation [8][9][10][11][12]. The suggested sequence includes the formation of C-S-H as the first reaction product in the ASR process.…”

“…Once the available Ca(OH) 2 is completely consumed, the concentration of silica (Si) in the reacting system increases and this increase leads to the subsequent formation of ASR gel [8,[10][11][12].…”

“…Afterwards, these dissolved silica ions combine with potassium (K + ), sodium (Na + ) and calcium (Ca 2+ ) ions, and produce calcium silica hydrates (C-S-H), calcium alkali silicate hydrates, and ASR gel [6][7][8][9][10].…”