Fewer cracks in concrete structures thanks to superabsorbent polymers?

(29-06-2021) José Roberto Tenório Filho investigated in his PhD whether superabsorbent polymers can reduce cracks in large concrete structures under realistic conditions.

Superabsorbent polymers (SAPs) are present in a wide range of products in our daily life (e.g. diapers). Over the past two decades they have also been extensively studied as a new admixture for cementitious materials. But how do we go from diapers to concrete structures? Due to their ability to absorb and retain water, SAPs can be successfully used for internal curing (which is the internal provision of water to the concrete to prevent self-drying and reduce autogenous shrinkage – one of the main causes of cracks at the early age of the structure). In addition, they can promote self-sealing and crack healing.

Although much research has been conducted and progress has been made, there is still a lack of studies on the use of SAPs in large-scale concrete structures. In this thesis, two commercially available SAPs and eight "in-house developed" SAPs were investigated. Five reinforced concrete walls (14 m x 2.75 m x 0.80 m) were constructed under realistic conditions in Bruges: two reference walls without SAPs, one wall with a commercial SAP, one wall with an "in-house developed" SAP, and one wall with a combination of both SAPs.

"The addition of SAPs completely prevented cracking in the SAP-containing walls during the nine months of monitoring, with a limited effect on the compressive strength of the concrete. In contrast, in the reference walls, the first cracks were noticed 5 days after pouring. Moreover, a reduction of the shrinkage reinforcement by at least 10% was possible for the walls containing SAPs", says José Roberto Tenório Filho.

The PhD research was financed by SIM-Flanders and had as industrial partners the companies Artes Depret, InterBeton and Chemstream bv.

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Contact:  José Roberto Tenório Filho

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View the full PhD:  Innovative Superabsorbent Polymers for Crack Mitigation of Concrete Structures: From Laboratory to Construction Site

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Editor: Jeroen Ongenae - Final editing: Ilse Vercruysse - Illustrator: Roger Van Hecke