Thick concrete overlays in Belgium

The technique of con5tructin~ thick concrete overlays is at present being greatly developed in Belgium. Three periods are to be distinguished in overlay construction in this country: 1960 to 1969: experimental phase in which 210.000 m2 of overlay was constructed; 1970 to 1977: the second phase, in which the results obtained were assessed and methods were refined and in which an area of 122.000 m2 was constructed; - 197B to the present time: the third phase, in which this technique has been used very extensively, with an area tocalling 3 million m2 expected to be constructed by the end of 19B6. Some of the latest projects more particularly call for mention. These are concrete overlays on motorways: E 40 (Brussels - Namur); A 12 (Brussels - Antwerp) E 5 (Liège - Aix-la-Chapelle); E 3 (Ghent - Courtrai) The examples presented in the paper are illustrated with drawings of cross-sections and with colour slides. It is moreover to be noted that this technique is being extended to secondary roads and even to minor country roads.