Monitoring Of Fresh Concrete With Superabsorbent Polymers (SAPs) Using Acoustic Emission (AE)

In fresh concrete, early-age shrinkage is affected by many factors, such as thermal deformations moisture loss and the hydration reaction. Novel admixtures for internal curing, like SuperAbsorbent Polymers (SAPs) can be used to mitigate the shrinkage phenomenon. These admixtures strongly modify the microstructure influencing the Acoustic Emission (AE) activity. Acoustic emission has been proven adequate to monitor activities during the curing of fresh cement-based materials. However, so far, it is difficult to distinguish the original mechanisms due to the overlapping nature of the processes that take place. In addition, localization of AE sources is not possible due to the heterogeneous and damping nature of the fresh material. The motivation of this study is to obtain real-time information on the different ongoing processes in fresh concrete, like settlement and shrinkage cracking, using AE and comparing the results to concrete containing SAPs. A preliminary study for 3D source localization in fresh concrete is also performed. The goal is to control concrete curing and confirm suitable final mechanical properties, resulting therefore in more sustainable materials.