Investigation of microstructural development in mortars with recycled paper ash used as cement replacement, using NMR relaxometry

For the investigation of porous media with applications in the field of civil engineering on concrete and mortar, NMR technology is used, with emphasis on the sensitivity of 1H hydrogen protons to pore filling fluids. NMR technology was used to highlight the changes that replacing cement with recycled paper ash powder in mortar recipes brings at a molecular level. The samples are analyzed during 56 days, at predetermined deadlines depending on the evolution of cement compounds hydration. Ability of recycled paper ash to replace cement in its role as binder is analyzed and the results obtained from mechanical tests are correlated with the structure and volume of pores in the control samples. Mixture compositions and C–S–H characteristics are calculated based on NMR signal intensities and relaxation analysis.