Hi Ajay,
I investigated the effect of Si/Al ratio and touched about Molarity briefly in my recently published paper (Jan, 2016 can be referred in my profile). Further suggested readings are Peter Duxson and Deventer of Melb uni.
To summarise, Increased Molarity means a better rate of dissolution until an optimum is reached. Past this optimum, the dissolution decreases slightly.To illustrate, it is like a bell-shaped curve (Reactivity vs. Molarity).
If you need pdf copies of the papers, let me know and I can send by email/message
Dear Ajay,
Generally, higher M of alkalinity results in a mixture with a higher workability and a higher strength. However, if M is too high, it may negatively affect the mechanical properties of the geopolymer. Since the reaction products cover the surface of the precursors rapidly and therefore, avoid the further geopolymerisation of the precursor's grains.
In addition, very high amount of alkali (un-bounded Na in the mixture) in a geopolymer mixture can lead to carbonation problem.
Compressive strength usually increases with increasing molarity, but excessive molarity has negative effects on resistance.
Its effects depends on the chemical composition of precursor materials, for high calcium material, high PH environment might result in quick/flash hardening. also the CA in precursor material easily dissolve in low hydroxyl concentration.
- Badges
- Science topic
- Similar topics
- Engineering
- Civil Engineering