Tsuzuki who is specialised in designing and manufacturing concrete segment for shield tunnels, has acquired ISO9001 certification for Head Office and Saitama Plant. Scope of supply of the certification is Design and manufacturing of structural precast concrete civil engineering elements: Reinforced concrete (Including unreinforced and nominally reinforced) The certification has been given by BVQI under UKAS (United Kingdom Accreditation Service) and also been accepted by RAB (USA) and RVA (Holland).