Enhance mechanical damping behavior of RHA-cement mortar with bionic inorganic-organic laminated structures

Abstract

To reduce the threat of dynamic loads, the anti-vibratory performance of the building structure is improved by using materials possessing excellent damping properties. Inspired by the microstructure of shells, the bionic inorganic-organic laminated structures which consisted of RHA, thin layer polymer and cement-hydrates matrix are built and used to enhance the damping properties of cement mortar. A nanometer-sized bionic function interface is prepared by immobilizing methyl methacrylate (MMA) and styrene (ST) onto rice husk ash (RHA), which is firstly modified by vinyltriethoxysilane (VTES). Detailed characterizations including FT-IR, TG, XRD, BET, contact angle, and SEM are conducted to investigate the surface characteristic of RHA. The loss tangent, storage modulus, loss modulus, porosity, compressive strength, and flexural strength are tested to investigate the effect of bionic inorganic-organic laminated structures on cement mortar physical properties, and hydration products are interpreted by the adoption of XRD and FT-IR. The test results of cement mortar show that compared with the loss tangent value of plain cement mortar (0.02219), the loss tangent value of the cement mortar containing 12% wt.% RHA (0.02575) shows an obvious increase of 16.05%. Moreover, compared with the cement mortar containing 12% wt.% RHA, the loss tangent of the cement mortar containing 12% wt.% modified RHA (0.0363) is significantly increased by 40.97%. This indicates that the built and use of bionic inorganic-organic laminated structures can effectively enhance the damping properties of cement mortar by multi-phase viscoelasticity interface interaction.