Impact Response of Autoclave Aerated Concrete/FRP Sandwich Structures

Abstract

A novel concept of hybrid fiber-reinforced polymer (FRP) - Autoclaved Aerated Concrete (AAC) sandwich panels have proven to be a structurally efficient combination for lightweight structural components. The FRP composite material was made of carbon reinforcing fabrics embedded in an epoxy resin matrix. The carbon fiber reinforced polymer (CFRP) reinforcement was applied on the top and bottom faces of the AAC panel and several innovative processing techniques were used including hand lay up as well as vacuum assisted resin transfer molding (VARTM). Beside the need to have adequate flexural properties, the AAC-FRP sandwich structures need to be evaluated in their ability to withstand localized damage. During service, the structural members in the building structures are subjected to impact loading that varies from object-caused impact, blast due to explosions, to high velocity impact of debris during tornados, hurricanes, or storms. The objective of this paper is to evaluate the response of AAC-FRP sandwich structures to low velocity impact and to assess the damage performance of the panels. Low velocity impact (LVI) testing serves as a mean to quantify the allowable impact energy that the structure is able to withstand and to assess the typical failure modes encountered during this type of loading. Impact testing was conducted using an Instron drop-tower testing machine.