Effects of silane-functionalized nanocomposites in superabsorbent polymer and its reinforcing effects in cementitious materials.

As an internal curing substance for cementitious materials, superabsorbent polymer (SAP) is emerging as the most potential solution. Nanomaterials and their composites have wide applications in concrete mainly as crack sealants and viscosity modifiers. Silane, as a coupling agent, is utilized in cementitious materials for its effective particle dispersion and adhesion characteristics. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Thermogravimetry (TGA) analysis, and Scanning electron microscopy (SEM) are utilized to characterize the microstructures and phase compositions of nanoalumina, (3-aminopropyl) triethoxysilane (APTES) and polyacrylamide (PAM) SAP. The impacts of silane-functionalized nanoalumina combined polyacrylamide SAP in cementitious materials are carefully investigated in this work. Compared with plain SAP, the application of silane-functionalized SAP was found to exhibit increased compressive strength, flexural strength and split tensile strength of concrete. The chemical durability properties of cement mortar, rheological and mechanical properties of concrete under self-curing and water curing with cement replaced by the prepared composites at 0.1, 0.2, 0.3, 0.4 and 0.5% by weight of cement are studied experimentally. Results revealed that silane-functionalized nanoalumina modified SAP has good water holding capacity than those with individual SAPs contributing to the advancement of internal curing materials in concrete buildings. The weight loss measurements reveal that lower weight loss is observed for the concrete containing SAP/APTES/nanoalumina in chloride, acidic and sulphate media. This work contributes to the advancement in material technologies for the prevention of building fractures. [ABSTRACT FROM AUTHOR]