A continuously reinforced concrete pavement (0.35 m thick) for the steel mill Sidmar in Belgium

The project consists of the construction of a continuously reinforced steel slag concrete pavement (0.35 m thick) on a base course of slag sand-bound granular material (0.85 m thick). The road (area 8,000 m2, width 10 and 17 m) has to lenable the transportation of hot (800 0 C) steel slabs by means of heavy slab carriers from the continuous foundry of the steel mill SlOMAR in Belgium. The slab carriers have a rear axle load of 175 tons, distributed over two wheels which induce a contact pressure of 7.44 kg/cm2 per wheel. The overall pavement structure was designed by using the anisotropic multilayer theory of Dr. F. VAN CAUWELAERT. With this theory, the pavement base is simulated mathematically as a uniformly cracked coarse , aggregate base in the horizontal direction and as a hydraulically bound material in the vertical direction. As the use of joints would have resulted in very high stresses at the edges and comers of the pavement slabs and because of the expected detrimental effect I of the heat on the joint sealant material, a continuously reinforced concrete pavement without trans- ~ verse joints was opted for. The cross sectional area of longitudinal reinforcement is 0.68 % of the concrete cross section. The required reinforcement was placed in two layers and consisted of two bars ~ 16 mm, each bar placed at 1/3 and 2/3 of the thickness of the concrete slab respectively (longitudinal spacing 0.17 m). The occurrence of excessive stresses at the left and right edges of the pavement slab was avoided providing I an overwidth of the pavement and by supporting the pavement edge by a longitudinally continuous slab of lreinforced concrete (2.50 m wide and 0.25 m thick). The steel slag concrete is composed of blast furnace slag cement, broken blast furnace slags, slag sand and ground slag sand. The selection of the concrete composition results from the consideration of exposure to heat radiation from the hot steel slabs and of enabling the use of by~products of the mill. The pavement was poured over the full depth and over widths of 8.50 m and 10 m. The longitudinal construction J01nts were of the tongue and groove type with tie bars. Separately cast fillets placed at intersections consisted of reinforced concrete slabs with a thickness of 0.60 m. The project was executed during the end of 1984. It is expected to obtain a first evaluation of the behaviour of this pavement towards the end of 1985.