In connections between precast concrete panels and the supporting structure, one of the most relevant critical issues concerns the need to manage installation tolerances without compromising the final behaviour of the joint.
The actual position of the element may differ from the theoretical configuration defined in the design. The anchoring system must therefore allow adequate adjustment during installation and, once alignment has been completed, ensure the controlled transfer of tensile and shear actions, including those acting in the direction of the slot.
Concreteslot is the slotted insert developed by B.S. Italia to meet this requirement. The compact configuration of the component makes it possible to integrate adjustability, dry locking and resistant behaviour within the precast element, while maintaining reduced depth dimensions.
Table of contents
- Joint adjustment during installation
- Anti-sliding knurled surface and dry locking
- Transfer of tensile and shear actions
- Hackled shape and integration in concrete
- Anti-pull-out concrete cone and slot ribs
- Performance in real installation conditions
- Connection configurations
- Concreteslot in adjustable anchoring systems for precast elements
- Frequently asked questions
Joint adjustment during installation
During the installation of a precast panel, even limited geometric deviations can make coupling with the supporting structure more complex. Without an adequate adjustment margin, corrective work may have to be carried out directly on site.
The slot in Concreteslot makes it possible to manage this phase in a controlled way. The system allows adjustment of up to 20 cm, providing sufficient margin to compensate for installation tolerances and reach the correct position before final tightening.
Adjustment is therefore not an occasional adaptation, but a function integrated into the anchoring joint. The connection is designed to absorb actual installation deviations without modifying the configuration defined by the project.
Anti-sliding knurled surface and dry locking
One of the distinctive aspects of Concreteslot is the presence of an anti-sliding knurled surface along the slot.
This configuration makes it possible to move from an initial adjustable phase to a final locked configuration. After alignment of the precast element, the connection can be tightened, counteracting displacement in the same direction used for adjustment.
The system therefore makes it possible to manage two normally opposing requirements:
- maintaining freedom of adjustment during installation;
- preventing unwanted movements once assembly has been completed.
The possibility of obtaining a dry connection also makes it possible, in the intended configurations, to avoid additional operations such as welding or supplementary casting.
Transfer of tensile and shear actions
In adjustable systems, the direction of the slot is one of the most delicate points of the connection.
It is the direction along which initial alignment is carried out, but also the direction in which the joint must ensure controlled behaviour in its final configuration.
Concreteslot is designed to resist tensile and shear actions in two directions, including the direction of the slot.
The configuration of the system therefore makes it possible to counteract:
- tensile actions;
- shear actions transverse to the slot;
- shear actions in the direction of the slot.
This behaviour is particularly relevant in connections subject to horizontal or vertical actions, including those generated by seismic forces.
One typical application concerns the dry locking of possible displacements of roof slabs, obtained without using welding or supplementary casting.
Hackled shape and integration in concrete
The behaviour of Concreteslot does not depend only on the configuration of the slot. The lower part of the insert is also designed to integrate effectively within the precast element.
The hackled shape allows the component to overlap the reinforcement of the manufactured element without interfering with it and without requiring dedicated additional reinforcement.
This aspect simplifies insertion of the slot within the existing reinforcement and reduces the need for local modifications during production.
The openings on the bottom also facilitate the entry of concrete into the insert during casting, improving adhesion between the component and the precast element.
The result is a system that self-anchors in the concrete and can be integrated into the manufactured element while maintaining compact dimensions.
Anti-pull-out concrete cone and slot ribs
The geometry of the insert is designed to develop an anti-pull-out concrete cone around the component.
The cone starts below the typical level of the reinforcement of the manufactured element and involves the surrounding concrete volume. Force transfer is therefore not concentrated exclusively near the surface.
The slot ribs also contribute to the resistant behaviour of the system and distinguish Concreteslot from a traditional slotted configuration without specific geometric reinforcements.
The combination of hackled shape, bottom openings, ribs and development of the anti-pull-out concrete cone makes it possible to obtain an adjustable connection that is also integrated into the structural behaviour of the precast element.
Performance in real installation conditions
Installation conditions do not always coincide with the ideal theoretical configuration. For this reason, adjustability must be accompanied by predictable behaviour even in the presence of permitted deviations.
In compliance with the minimum parameters indicated in the technical manual, Concreteslot maintains the declared load values even with the insert inclined up to ±10° and with the connection positioned near the end.
This allows the adjustment margin of the system to be used without losing control of the performance expected from the joint.
Design must in any case consider the correct positioning of the insert, the minimum distances from the edges and the possible need for confinement according to the configuration of the precast element.
Connection configurations
Concreteslot can be completed with different components depending on the geometry of the joint and the supporting structure.
The system includes three main options:
- screw with anchor head;
- adjustable plate;
- adjustable plate for welding.
These configurations are complemented by dedicated accessories for specific applications, such as the anti-sliding adjustable plate, the vice system, the quadriribbed bracket and the extension.
The different solutions allow Concreteslot to be used in connections between precast panels and reinforced concrete or steel structures, adapting the joint to the actual design and installation conditions.
Concreteslot in adjustable anchoring systems for precast elements
Concreteslot is a specific solution for joints in which adjustability and force transfer must be managed in a coordinated way.
The system makes it possible to compensate for tolerances during installation, dry-lock the connection after alignment and counteract shear also in the direction of the slot.
The self-reinforcing hackled shape, the bottom openings, the ribs and the development of the anti-pull-out concrete cone also allow the component to be integrated within the precast element without requiring additional reinforcement.
Within the adjustable anchoring systems for precast elements developed by B.S. Italia, Concreteslot is therefore a technical solution designed to control the behaviour of the joint both during installation and in its final configuration.
Frequently asked questions
What is Concreteslot used for?
Concreteslot is used to create adjustable connections between precast elements and supporting structures, allowing installation tolerances to be compensated and tensile and shear actions to be transferred in a controlled way.
What is the advantage of the adjustable slot?
The adjustable slot makes it possible to correct the position of the element during installation, providing an adjustment margin of up to 20 cm before final tightening of the connection.
Why is the anti-sliding knurled surface important?
The anti-sliding knurled surface allows the connection to be dry-locked after alignment, counteracting displacement in the same direction as the slot.
Does Concreteslot always require additional reinforcement?
Concreteslot is designed with a self-reinforcing hackled shape and bottom openings to favour integration in concrete. Any need for reinforcement or confinement must be assessed according to the configuration of the precast element and the technical design requirements.
In which conditions is Concreteslot useful?
Concreteslot is useful in joints where adjustability, dry locking and force transfer must be managed, including in the presence of horizontal, vertical or seismic actions.
