Noise barriers supplied by Vinh Hung IP, which meet all current standards, are able to minimize the noise affecting surrounding area (residentialareas, hospitals, schools, industrial parks, etc.) and ensure a fine landscape. The noise barriers are windproof and aid to driver's concentration which could increase safety for people and other vehicles. PRODUCT CHARACTERISTICS Absorptive noise barrier: Using sound-absorbing materials, punch plates, etc., which prevent sound reflection. Sound absorption standard rating: Noise Reduction Coefficient NRC describes the average sound absorption performance of noise barrier. For the absorptive noise barrier, the NRC will be within 0.6 to 0.9 range (FHWA highway noise barrier design handbook). Reflective noise barrier: Using good noise insulation materials such as Polycarbonate panels (PC), Poly methyl methacrylate panels (PMMA), Glass laminate. Sound reflective standards: Transmission loss coefficient TL will measure the amount of sound energy hitting on or transmitted through the barrier. For the reflective noise barrier, the TL coefficient is >25 dB at 500HZ and >30 dB at 1000HZ (according to KS F4770 standard). INSTALLATION Preparation: Prepare installation materials, tools and equipment. Check the surface of base structure: - Check the distance among the anchor bolts. - Check the dimensions of posts flanges, positions of bolt holes and anchor bolts.