Assessment of the potential of superabsorbent polymers as internal curing agents in concrete by means of optical fiber sensors

Superabsorbent polymers (SAPs) have been widely explored in concrete technology for their promising application as internal curing agents. SAPs reduce shrinkage deformation and the risk of early-age cracking. In this paper, the efficiency of SAPs is assessed with mechanical strain gauges and long-gauge optical fiber sensors embedded inside the matrix. Two commercial and two in-house developed SAPs are used. The commercial SAPs and one of the in-house developed SAPs completely mitigated the autogenous shrinkage of concrete and all four reduced in 30% the total shrinkage. The optical fiber sensors performed better than the mechanical strain gauges and identified crack formation.