Shrinkage Mitigation and Mechanical Properties of Cement‐Based Mortar With Silane‐Functionalized Hydrogels

ABSTRACT This study investigates the applications of silane‐loaded polymer hydrogels in field‐relevant cement‐based mortar intended for future 3D printing applications. The gels utilize a silane monomer, 3‐(trimethoxysilyl) propyl methacrylate (TPM), to chemically integrate into the cement matrix while maintaining a swelling capacity sufficient to aid internal curing. Three variations of silane‐loaded gels were compared to a commercially available acrylic acid‐co‐acrylamide hydrogel. Mortar samples were prepared with varying water‐to‐cement ratio to maintain a pre‐defined workability of 22 cm ± 1 cm across mixes containing gels with different swelling properties. The gels' internal curing ability was measured through autogenous and drying shrinkage measurements. The synthesized gel with the lowest silane loading (5% silane) reduced autogenous shrinkage by 20% while exhibiting 23% less drying shrinkage compared to the reference mix of the same workability. Mortar samples containing the silane‐loaded gels maintained compressive strength values of 70–80 MPa required for high performance concrete while maintaining workability. Furthermore, mortar samples containing silane loaded gels met, and at times exceeded, the flexural strength of 9 MPa provided by the reference mix of the same workability. Microscopy performed on 7‐day samples showed improved integration of the silane‐loaded gels into the mortar matrix.