Internally Cured High-Performance Concrete Slabs Reinforced with Glass Fiber-Reinforced Polymer

This paper presents a new concept of high-performance structures composed of internally cured concrete and glass fiber-reinforced polymer (GFRP) reinforcement. The former addresses autogenous shrinkage that leads to premature cracking of concrete, and the latter provides a noncorrosive service environment. Presaturated superabsorbent polymer (SAP) is mixed with concrete at 0 to 0.4% of the cement mass to facilitate a hydration process. The swelling kinetics of SAP due to water absorption is quantified, and its releasing rate with time is determined. A total of 15 one-way slabs are tested in flexure to examine the effects of SAP inclusions. The behavior of the slabs is assessed by deterministic and stochastic models with an emphasis on tension stiffening and performance reliability. The amount of the internal curing agent affects the strength of the concrete and the response of the slabs. Various cracks are observed when the slabs are loaded, including flexural, horizontal splitting, and diagonal tension cracks. As the amount of SAP increases, the cracks become localized and expedite the failure of the slabs. The tension stiffening of control slabs (0%SAP) is more pronounced than that of the slabs with SAP. The cumulative degradation probability and the risk level of the slabs made of the internally cured concrete are controlled by the amount of SAP.