(19)

(11)

EP 0 837 970 A1

(12)

(43) Date of publication: 29.04.1998 Bulletin 1998/18 (21) Application number: 96925754.0 (22) Date of filing: 10.07.1996

(51) International Patent Classification (IPC):  E01D 2/ 04( . ) E04C 3/ 29( . ) E04B 5/ 02( . ) (86) International application number: PCT/EP1996/003102 (87) International publication number: WO 1997/003249 (30.01.1997 Gazette 1997/06)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 11.07.1995 NL 19951000770 (71) Applicants: Akzo Nobel N.V. 6824 BM Arnhem (NL) Grontmij Advies & Techniek B.V. 3730 AE De Bilt (NL) Polymarin B.V. 1670 AD Medemblik (NL)	(72) Inventors: ZWART, Walther, Hendrik NL-3904 DJ Veenendaal (NL) DALMOLEN, Lambertus, Gerrit, Peter NL-6844 GN Arnhem (NL) ROB, Alphonsus, Joannes NL-1671 EV Medemblik (NL) (74) Representative: Schalkwijk, Pieter Cornelis, et al  Akzo Nobel N.V. Patent Department P.O. 9300 6800 SB Arnhem 6800 SB Arnhem (NL)