On mitigating rebar–concrete interface damages due to the pre-cracking phenomena using superabsorbent polymers. (30th August 2020)

• Record Type: Journal Article
• Authors: Mousavi, Seyed Sina; Ouellet-Plamondon, Claudiane M.; Guizani, Lotfi; Bhojaraju, Chandrasekhar; Brial, Victor
• Is Part Of: Construction & building materials. Volume 253(2020)
• Publication Date: 2020-08-30
• Subjects: Bond-slip -- Pre-cracking phenomena -- Steel rebar -- Superabsorbent polymers (SAP) -- Self-healing -- Reinforced concrete; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.119181
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Low dosage of SAP has comparable bond strength in uncracked concrete. Large-size SAP has similar bond strength, as compared to the smaller size. High dosage of SAP has considerable effect on self-healing at rebar-concrete interface. Self-healing at rebar-concrete interface has no effect on splitting bond failure. EDS test confirms a considerable mass percent of calcium in the healed products. Abstract: This study intends to determine the effects of incorporating superabsorbent polymers (SAP) within concrete on the bond properties of steel reinforcing bars (rebar) embedded in uncracked and pre-cracked concrete. An experimental program is conducted to check the performance of SAP, as a healing agent inside the concrete, in mitigating internal damage at the rebar-concrete interface due to the pre-cracking phenomena. Two types of SAP with different particle sizes (0.15 and 0.50 mm) and chemistries are considered in the experimental program. Pull-out test results show improved bond properties of steel rebars embedded in uncracked and healed concrete containing lower dosages of SAP. However, concrete containing a high dosage of SAP shows lower bond strength, compared to normal concrete, due to the presence of macro voids. A considerable healing effect is observed for the initial bond-slip curve portion, the bond strength, and the energy absorbed by the bond mechanism, within the cracks of pre-cracked SAP-modified concrete subjected to wet-dry cycles. This study shows that SAP can significantly increase the autogenous healing performance of concrete at rebar-concrete interfacial damage sites.