NANOCLAY REINFORCED POLYMER COMPOSITE AND ITS APPLICATION TO HYBRID COMPOSITE STRUCTURES

Abstract

The purpose of this study was to find the optimum mixing technique that leads to maximum gain in mechanical, thermal, and fire-retardant properties of vinyl ester based nanocomposites. Specifically, five combinations of incremental mixing intensity were applied to five groups of samples that were made of vinyl ester resin reinforced by 1 wt. % of montmorillonite (MMT). Changes in mechanical properties associated with each mixing combination were examined through a variety of tests, which were low velocity impact test, bending test, compression test, and dynamic mechanical analysis (DMA). Additionally, changes in thermal properties (e.g., thermal diffusivity, glass transition temperature) and fire-retardant properties associate with each mixing combination were also evaluated. The result was compared with pure vinyl ester resin. Finally, an optimum mixing combination was proposed. In order to additionally approve the effect of exfoliated MMT/VE, it was introduced to Advanced Grid Stiffened Fiber Reinforced Polymer (AGS-FRP) tube encased concrete cylinders and to improve their fire resistant behavior and mechanical property. MMT reinforced AGS-FRPC cylinders was fabricated and tested. This paper presents test results of temperature distributions and residual strength of 2 groups of AGS-FRPC cylinders with or without MMT reinforced (Groups A and B), which were exposed to a jet fire of 982oC for a time period of 5 minutes. The temperature distribution of the AGS-FRPC cylinders under fire was recorded by the embedded thermocouples. After fire test, uniaxial compression tests were conducted to evaluate the residual strength. The results were compared with that from a group of AGS-FRPC cylinders without fire exposure (Group E and F). To improve the fire resistance of the confined concrete cylinders, a fireproof additive was also applied to 2 other groups of specimens (Group C and D) and these specimens were also fire tested for 5minutes. And the results were compared with that from a group of AGS-FRPC cylinders without fire exposure (Group G and H). The final results show that the fire exposure has a significant effect on reducing the residual strength of the confined concrete cylinders. The introduced MMT increased the fire resistance and compression strength of AGS-FRPC cylinders. The fireproof additive used is effective in minimizing the effect of the fire hazard, but reduce some compression strength.