A BUILDING STRUCTURE, PARTICULARLY A ROAD BRIDGE STRUCTURE

Abstract: A building structure, particularly a road bridge structure, has an upper part (6-10) adapted to carry traffic, and a lower part (2) supporting the upper part. The two parts are separated by a non-adhesive, low friction membrane (1) having hood portions (4) fitting around anchorage blocks (3) projecting upwards from the surface of the lower part. The upper part comprises a course of pavement blocks (7) in which blocks are omitted to form a void around each anchorage block (3), the voids being filled with concrete (9). At least one asphalt layer (10) is laid on top of the pavement blocks (7). Liquids penetrating through the upper part are prevented by the membrane (1), including the hood portions (4) from penetrating into the lower part (2) and are drained off above the membrane (1). Horizontal forces resulting from traffic are transmitted via the asphalt layer (10), the pavement blocks (7), the concrete filling (9), the hood portions (4) and the anchorage blocks (3) to the lower part (2).

Description: A building structure, particularly a road bridge struc¬ ture. The invention relates to a building structure of the kind set forth in the introductory part of claim 1. A particularly important field of use of such a build¬ ing structure is for road bridges, where the lower part consists of a supporting beam of reinforced concrete covering a span of the bridge, while the upper part serves to carry the traffic and to transfer both verti¬ cal and horizontal forces resulting from the traffic to the lower part. The invention will in the following be described with particular reference to that field of use, but it will be realized that the invention may likewise be used for other building structures where similar problems exist. A building structure of the kind referred to is known from PCT/DK 90/00211. An important feature of that structure is that the membrane is practically not sub¬ jected to shearing or tearing stresses, because hori¬ zontal forces resulting from changes of speed and di¬ rection of vehicles driving and anoeuvering on the bridge are transferred to the anchorage blocks of the lower part in a direction perpendicular to the mem¬ brane portions covering the flanks of the anchorage blocks. In the embodiments disclosed in PCT/DK 90/00211, the upper part comprises a continuous layer of re-inforced concrete moulded on top of the membrane and forming the recesses to accomodate the hood-clad anchorage projections of the lower part. There is however a risk that under unfavourable conditions cracks may be formed in such a layer when the lower part undergoes elastic vibrations under the traffic load. In the case of repeated vibrations the cracks are enlarged because the concrete is crushed and crumbles along the edges of the cracks, whereby the lifetime of the upper part can become unsatisfactory without, however, impairing the safeguard against penetration of liguids into the lower part of the structure. To preclude this contingency, the invention is charac¬ terized by the features set forth in the character¬ izing clause of claim 1. In a course of pavement blocks no cracks can be formed, because the joints between the blocks are suffiently pliant to absorb any vibrating forces to which the blocks may be subjected by the lower part. The concrete poured into the voids of the course of pavement blocks may be of a type expanding in the pro¬ cess of setting, in order to obtain a closer fit of the concrete against the inner and outer contours of the voids, i.e. between the hood portions covering the flanks of the anchorage blocks, and the side faces of surrounding pavement blocks. When, in a road construction, a course of pavement blocks is laid on a gravel bed, it is usual to fill the joints between the blocks with multi-grade sand, i.e. sand having grain sizes distributed over a rela¬ tively large range. Such a sand material has the prop¬ erty that when compressed it becomes very compact with a minimum of pore volume. That makes the sand mechan¬ ically stable and capable of transferring a certain amount of vertical forces from block to block, whereby the depression of the edge of a block under the load of traffic is counter-acted by next block. This mutual supporting effect of the blocks is not re- quired in the course of pavement blocks used according to the invention, because the blocks are laid on a solid base formed by the lower part covered by the mem¬ brane. It is therefore possible to use a sand filling material of relatively uniform grain size, such as beach sand, which, when compressed, has a much higher pore volume than multi-grade sand, and a correspondingly higher penetrability to liquids, and is therefore more suit- able for draining off liquids collecting on the free surface of the upper part. Preferably the pavement blocks are laid on a thin layer of the same sand material spread on the upper surface of the membrane or a hydrophilic layer placed on top of the membrane in the same manner as disclosed in PCT/DK 90/00211. The upper surface of the course of pavement "blocks, in¬ cluding the surface of the concrete filling the voids, is in itself capable of carrying traffic, even heavy load traffic, such as service traffic during the con¬ struction period. If the structure is to carry normal traffic, it is however preferable to lay at least one layer of asphalt on top of the course of concrete pave¬ ment blocks and adhering thereto. Thereby the free sur- face of the structure assumes the character of a normal road surface, and besides the asphalt has the function of locking the pavement blocks against acci¬ dental lifting or tilting under the influence of high speed traffic. With the exception of the differences following from the above explanation, all features and functions of the building structure disclosed in PCT/DK 90/00211 are applicable to that of the present invention. The invention will now be further described with refer¬ ence to the drawings in which Fig. 1 is a partial vertical section through a build¬ ing structure according to one embodiment of the inven¬ tion, and Fig. 2 is a horizontal section along the line II-II in Fig. 1. In Fig. 1 a liquid impervious membrane 1 is loosely laid out on the upper surface of a reinforced concrete beam 2. Anchorage blocks 3 of a solid strong material are bolted to the upper surface of beam 2 and are covered with hoods 4 of the membrane material having horizontal collars 5 which are sealed to the membrane cloth 1. A draining mat 6 of hydrophilic material is placed on top of the membrane cloth 1. On the top of the draining mat a course of concrete pavement blocks 7 are laid in a thin layer of beach sand (not shown) . The joints 8 between the pavement blocks are likewise filled with beach sand. The pavement blocks 7 are of the well-known type having zig-zag contour portions fitting together in a firm bonding pattern, such as the product marketed under the trade-name of SF pave¬ ment blocks. Pavement blocks 7 are omitted in areas around each hood-clad anchorage block 3,4 so as to form voids which are filled with concrete 9 which may be of the expanding type to establish a particularly close fit between the hood-clad anchorage blocks 3-4 and the surrounding pavement blocks 7. A layer of asphalt 10 is laid on top of the pavement blocks and the surface of the concrete 9 filling the voids. This layer adheres to the pavement blocks and thereby locks these against accidental lifting or tilting under the influence of high-speed traffic, as previously mentioned. The avoidance of lifting or tilting of the blocks therefore does not depend on the thickness and weight of the pavement blocks 7. These can therefore be made considerably thinner and lighter than in a pavement laid on a gravel bed. The consequent reduction of the gravity of the pavement is particu¬ larly important in the case of bridge structures. 11 symbolizes the wheels of vehicles driving and manoeuvering on the bridge. The horizontal forces thereby exerted on the asphalt layer are transferred from this layer via the pavement blocks 7, the con¬ crete fillings 9, the hoods 4 and the anchorage blocks 3 to the beam 2.

Claims: CLAIMS: 1. A building structure comprising an upper part (7,8,9,10) having an exposed upper surface and consist- ing of building materials permitting the penetration of liquid collecting on said upper surface, a lower part (2) forming a structural support of the upper part, a liquid impervious membrane (1) interposed be¬ tween the lower part (2) and the upper part (7,8,9, 10) for the purpose of preventing the penetration of liquid through the upper part (7,8,9,10) to the lower part (2), distributed anchorage blocks (3) projecting upwards from the upper surface of the lower part (2) and fitting tightly in hood portions of the membrane (4,5), which again fit tightly in recesses formed in the upper part (7,8,9,10), the membrane (1) consisting of a non-adhesive material having practically zero friction at least towards the areas of the upper part (7,8,9,10) with which it is in contact, characterized in that the upper part (7,8,9,10) comprises a course of concrete pavement blocks (7), in which blocks are omitted to form a void (9) around each of the hood- clad (4) anchorage blocks (3), the voids (9) being filled with concrete poured in situ and forming the recesses accommodating the hood-clad anchorage blocks (3,4). 2. A building structure as in claim 1, characterized in that the concrete poured into the voids (9) is of a type expanding in the process of setting. 3. A building structure as in claim 1 or 2, charac¬ terized in that the joints of the pavement course (8) are filled with sand of relatively homogeneous grain size, such as beach sand. 4. A building structure as in any of the beforegoing claims, characterized in that it further comprises at least one layer of asphalt (10) laid on top of the course of concrete pavement blocks (7) and adhering thereto. 5. A building structure as in any of the beforegoing claims, characterized in that it further comprises a drainage layer of hydrophilic material (6) interposed between the upper surface of the membrane (1) and the course of concrete pavement blocks (7). 6. A building structure as in any of the beforegoing claims, characterized in that the concrete pavement blocks (7) are of the type having zig-zag contour por¬ tions fitting together in a firm bonding pattern.

Inventors: THYGESEN SOEREN, THYGESEN, SOEREN
Applicants: THYGESEN SOEREN, THYGESEN, SOEREN
Application year: 1991
Main classification: E01D19
IPC codes: E01D19