A SIMPLE AND LOW COST METHOD FOR RAPID ASSESSMENT OF AIR VOIDS IN HARDENED CONCRETE

Presented herein is a new technique and a low cost method to estimate the ratio of air voids in hardened concrete within 30 minutes using available flatbed scanner, black inkjet, personal computer and image treatment software This test method includes contrast enhancement steps ensuring black ink (air voids) in gray concrete (aggregate and paste), image acquisition and computer analysis of scanned image. It is applied on specimens of normal concrete (NSC), high strength concrete (HSC) and high strength concrete with Polypropylene fibers. Results obtained are compared with the peer values of wet concrete ratios of air voids. As compared with other ASTM procedures, it is concluded that this method may have superiority over other methods due to its simplicity, low cost, less time and no need of skilled technicians. It is recommended to be used for hardened concrete as well as rock specimens.