Monitoring hydration of UHPC and conventional paste by quantitative analysis on Raman patterns

• Raman spectroscopy is used to track hydration process in different cement pastes.
• Quantitative analysis on peak area of Raman patterns is applied.
• Raman spectroscopy is sensitive enough to differentiate conventional cement hydration and pozzolanic reaction.

Cement hydration governs physical, chemical and mechanical properties of cement pastes. Therefore, tracing hydration progress in different types of cement pastes can help to understand different hydration mechanisms and paste behaviours. In the present research, a quantitative analysis on Raman spectroscopy (RS) patterns for conventional cement paste and ultra-high performance concrete (UHPC) matrix at different hydration ages has been applied. It has been found that quantitative analysis on peak area of Raman patterns is fully capable to differentiate between conventional cement hydration and pozzolanic reaction in UHPC. The result also showed that silica fume included in the UHPC matrix was more reactive at early ages, which was completely in agreement with reduction of calcium hydroxide (CH) content at the same hydration period.