The manufacture of every ton of cement emits approximately 0.8 tons of CO2 into the atmosphere, comprising 5-7% of the global human-made CO2 emissions. A low pH - low CO2 class of alkali activated materials consisting of a nanoscopic phase of an Al-substituted C-S-H, called C-A-S-H, is one of the most promising replacements of traditional cementitious binders. C-A-S-H has improved durability and strength properties, as well as environment-friendly character (slag recycling and reduced CO2 emission). Little is known about the atomic structure of C-A-S-H and structural and dynamical properties of water within its pores. We propose to elucidate the H-bond dynamics of water in C-A-S-H, using a protocol that allows accessing the different pores of the C-A-S-H structure. This study will be key to construct a complete picture of water structure and dynamics in the different pores of C-A-S-H.