What is: continuous concrete with supported edges and seals.
From a point of view of construction performance concrete qualities are well known, durability, high elasticity modulus and workability, for instance, stand for them among many others. But it is also well known that unfortunately, not all its properties are on the positive side. Cracking, by a variety of reasons, including shrinkage, is a defective feature and accordingly, various technical procedures have been developed to avoid, limit or fill cracking by reinforcing and/or sealing.
The present system takes advantage of the natural development of shrinkage in concrete to induce the formation of joints along the line of previously placed patented devices. The system induces in a in-situ concrete pavement and efficient interlocking indentation between the slab elements resulting from shrinkage.
A patented ready-made device set extended along the previously chosen joints lines is able to ensure the alternate interlocking of neighbouring slabs after shrinkage has taken place. Shear is transmitted through the contact surfaces of the resulting joint.
The article “New load transfer solutions in construction and repair of roads, railways and concrete pavements” describes tests which were carried out to show that the transfer with JRI + system is permanent.
In traditional concrete pavements, load transfer is implemented based on the placement of dowel bars that connect the slabs together. This implies the need of designing high quality layers of significant thickness and guaranteeing the necessary elastic means for generating appropriate terrain response through the dowel bars, on the concrete slab.
This solution has a problem that affects conservation and pavement life due to the following factors:
High specific stresses in the contact areas between edges of slabs.
Plasticizing of concrete in areas of concrete-pin contact.
Long term oxidation of pins.
Given the usual dimensions of the slabs, high peak thermal stresses.
Need to cut and seal the joints and provide their maintenance.
Important field response needed..
Traditional pavement structure
In the dowel bar system, because the cutting is not transmitted permanently, in the event that a bituminous mixture layer were used, it must be thicker than in the JRI+ system.
PERMANENT LOAD TRANSFER SYSTEM
The STPC solution is based on the permanent load transfer amongst slabs leaning against each other. By being able to divide the floor in a greater number of slabs, the resulting structure is similar to a continuous beam with a significant reduction of tensions on each of the slabs. The critical load is at the center of the slab and not on the edge.
The load transfer is produced through the surface of teeth of the concrete slabs, with a much wider load transfer area as compared to the traditional dowel bar system.
STPC pavement structure (similar to continuous beam)