Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D27/00—Foundations as substructures
  • E02D27/01—Flat foundations

Definitions

• This invention relates to a monolithic foundation system with homopolymer/resistant aggregate pavement with a semi -continuous configuration, more specifically to a semi- continuous cement concrete pavement having joints formed by load transfer plates, with a structural strength which, by itself, absorbs, degrades and transmit loads, while withstanding the forces exerted thereon as well as the abrasion caused thereby, without differential settlements on the joint axis, also serving as a wearing course, the said pavement being laid on a foundation which is independent of the natural soil and acting as both a base and a sub-base .
• rigid pavements also comply with well-established rules.
• the standards usually considered for determining the pavement characteristics are closely related to aspects such as traffic, loads, sub-bed support and drainage.
• One of the main problems to be solved is the differential settlements between adjacent concrete slabs in pavements laid on elastic soils.
• load transfer elements are considered which minimize the loads projected on the foundation and prevent the settlement of the slabs.
• Another problem to be solved in the design of a rigid cement concrete pavement concerns the sealing of the joints between slabs.
• the basic function of the sealing of the induction slot in the joints of a concrete pavement is to prevent the intrusion of water and incompressible solid materials, such as sand, small stones and other foreign substances.
• Water infiltration through the joint has damaging effects on the durability of a pavement, essentially because it is the main cause of pumping, which consists of the deterioration of the foundation layer by expulsion of the grindings of which it is constituted, meaning that the board becomes unprotected and thus subject to degradation (this being known as the pumping phenomenon) .
• an object of the invention is the use of a semi-continuous cement concrete pavement having joints formed by load transfer plates, with a structural strength which, by itself, absorbs, degrades and transmits loads, while withstanding the forces exerted thereon as well as the abrasion caused thereby, without differential settlements on the joint axis, also serving as a wearing course, the said pavement being laid on a foundation which is independent of the natural soil and acting as both a base and a sub-base for supporting the said semi-continuous concrete pavement .
• the load transfer elements used by the system of the invention are basically the elements of prior art disclosed in Portuguese patent no. 102947, to which improvements have been made so that the use of polystyrene blocks in the foundations is permitted.
• Patent PT 102947 is herein incorporated for reference purposes .
• Figure 1 is a schematic illustration of the system of the invention
• Figure 2 is a schematic illustration of an expansion and contraction joint
• Figure 3 is a schematic illustration of a construction j oint ;
• FIG. 4 is another schematic illustration of the system of the invention.
• FIG. 5 is a perspective view of the load transfer plate of the system of the invention.
• Figure 6 is a main elevation of the load transfer plate of the system of the invention.
• an appropriate foundation Prior to pavement concreting, an appropriate foundation is built to receive the area of the pavement to be concreted, being comprised of several strips, each of them being formed by a sequence of slabs. In turn, the slabs must be confined by a formwork. Finally, the concreting of the slabs is carried out.
• the foundation (1) is obtained by the application of high-density expanded polystyrene blocks which, as a homopolymer, remains stable throughout the useful life of the system and, in terms of its technical specifications (density, deformation modulus) , has a steady behaviour without modification of the Westergaard modulus: K/cm 3 .
• the foundation (1) ensures the carrying capacity of the overall structure and must be designed to that end.
• the polystyrene blocks having densities and dimensions according to the design are laid over the natural soil (2) . Surface levelling errors should not exceed 5 mm in a 3 m ruler. In order to obtain an appropriate formwork, it is not necessary to fill it with inert materials of various granulometries and with possible frames, as is the case in prior art .
• base and sub-base foundation (1) used in the system of the invention since it is formed by high- density expanded polystyrene, it has specific technical characteristics which remain unaltered throughout the useful life of this material and which are essentially the following :
• polystyrene blocks replaces the base and sub-base of conventional foundations. These blocks also provide a formwork which is suitable for a continuous concreting.
• the level of the formworks will be according to the initial design elevation. Horizontal tolerance will be between 1 and 2 cm in length. The length of the formwork elements is limited in order to allow levelling and layout according to the design elevation.
• the pavement (3) After the laying of the foundation (1) and consequently the formwork, the pavement (3) can be concreted according to the established work specification.
• the concreting process comprises the following steps :
• the layout of the longitudinal profile will be realized on site with the aid of topographic precision instruments.
• the prescribed levels are verified by stakes placed solidly in the ground, outside the concreting corridor, at maximum intervals of 50 m, so that a rigorous longitudinal profile is formed parallel to the final elevation of the slab to be executed. In the case of curves, the distance between the stakes is reduced in order to exactly follow the profile of the design.
• the placing of the stakes must be carried out at least one day before the concreting operation. Unless there is a local impediment, to be recognized by the inspection authority, the preparation of the joints and the placement of the load transfer plates should precede the concreting by a distance of around 50 m, in order to ensure continuous implementation .
• the foundation In order to prevent any water absorption from the concrete to the foundation (1) , the foundation should be always covered with a sliding complex of approximately 0.2 mm and coverings of 20 cm.
• composition of the concrete will be sent to the inspection authority to be approved thereby. It must be in compliance with the pre-established conditions for each specific project.
• Manufacturing will preferably take place at the construction site and the equipment will have sufficient capacity to ensure a continuous laying operation.
• the type of transport will be subject to approval by the inspection authority, whether in a cement truck mixer or in a dump truck.
• the concrete may be laid and hand vibrated with a vibrating needle.
• All the edges of the slabs along the formworks will have to be vibrated using a needle vibrator. Atmospheric conditions Concreting will not be permitted during days of heavy rain.
• the surface treatment of the coating will be made by brushing the fresh concrete with brushes previously approved by the inspection authority.
• All the transverse and longitudinal joints are provided with load transfer plates .
• Contraction and expansion joints are according to figure 2.
• the sawing depth is of at least 2 cm.
• the construction joints are established at the end of each daily production or in the case of interruption of the concreting operation. As can be observed, the face of the joint must be flat and perpendicular to the surface of the coating. As soon as the concreting operation is restarted, the said joints are placed concrete against concrete, the face of the preceding slab being bathed with an anti-adherent agent, such as Antisol, in order to provide an effective separation.
• the pavement generically illustrated as (3) is formed by several slabs (4) which are provided with load transfer plates (5) .
• the said plates (5) are comprised of two anchors (6) with two rebars (7) for alignment of a joint inductor (8), and a ball joint (9) which, at the load support moment, rotates anticlockwise and, at the support moment generated by the load transfer plates (5) , performs a clockwise movement.
• This ball joint (9) is positioned under the joint inductor (8) and its centre is aligned with the vertical axis of the joint formed by the said inductor (8) .
• the said ball joint (9) releases the concrete slabs (4) from stress caused by bending/traction at the moment of load transfer, allowing the foundation (1) to be unaffected by bending moments resulting from the load and thus making the slab (4) work essentially with compression stress, thereby ensuring a safety coefficient much higher than the normal one and a long life of the foundation (1) of the slab (4) .
• the ball joint (9) releasing the concrete slabs (4) from stress caused by bending/traction at the moment of load transfer will thus allow the said concrete slabs (4) to work for a longer period of time with compression, i.e. releasing them from permanent stress and filtering most of the vibrations caused by rolling loads.
• the said slabs (4) will be subject to:
• this invention relates to a pavement (3) which has been successfully tested in all kinds of adverse conditions, having now a new conception of supports for joints, which consists of providing the load transfer plates (5) with ball joints (9) which, as previously mentioned, release the concrete slabs (4) from stress caused by bending/traction at the moment of load transfer, allowing the foundation (1) to remain unaffected by bending moments resulting from the load and thus making the slab (4) work essentially with compression stress.
• the ball joints (9) that foundations (1) with polystyrene blocks can be obtained. Joint sealing is required for protecting the foundation (1) against chemical agents/diluents.
• the foundation (1) must be coated along its upper and lateral parts with a plastic material .
• This material allows a reduction from about 2.5 to 0.5 in the friction coefficient of the slab (4) concrete when contracting and it also insulates the polystyrene blocks against any chemical attack resulting from spillages on the pavement surface (3) .

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Road Paving Structures (AREA)
• Foundations (AREA)
• On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
• Building Environments (AREA)

Priority Applications (11)

Applications Claiming Priority (2)

Publications (2)

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Citations (1)

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• 2008
  • 2008-07-04 PT PT104125A patent/PT104125B/pt active IP Right Revival
• 2009
  • 2009-07-03 PT PT97738181T patent/PT2356287E/pt unknown
  • 2009-07-03 US US13/002,560 patent/US20110170950A1/en not_active Abandoned
  • 2009-07-03 UA UAA201015968A patent/UA101505C2/ru unknown
  • 2009-07-03 WO PCT/PT2009/000039 patent/WO2010002285A2/en active Application Filing
  • 2009-07-03 PE PE2011000003A patent/PE20110234A1/es active IP Right Grant
  • 2009-07-03 JP JP2011516199A patent/JP2012503112A/ja active Pending
  • 2009-07-03 CN CN200980131914.9A patent/CN102388189B/zh not_active Expired - Fee Related
  • 2009-07-03 BR BRPI0915370A patent/BRPI0915370B1/pt not_active IP Right Cessation
  • 2009-07-03 EP EP09773818.1A patent/EP2356287B1/en not_active Not-in-force
  • 2009-07-03 CA CA2729779A patent/CA2729779A1/en not_active Abandoned
  • 2009-07-03 RU RU2010154175/03A patent/RU2509841C2/ru active
  • 2009-07-03 AU AU2009266512A patent/AU2009266512A1/en not_active Abandoned
  • 2009-07-03 KR KR1020117000829A patent/KR20110038669A/ko not_active Application Discontinuation
• 2010
  • 2010-12-31 MA MA33478A patent/MA32430B1/fr unknown
• 2011
  • 2011-01-02 IL IL210422A patent/IL210422A/en active IP Right Grant
  • 2011-01-04 CL CL2011000003A patent/CL2011000003A1/es unknown
  • 2011-02-02 EC EC2011010799A patent/ECSP11010799A/es unknown
  • 2011-02-03 CO CO11012633A patent/CO6341497A2/es active IP Right Grant

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