State of The Art Technologies
There are a number of ways of doing this such as via:
• Grouted Coupler to connect walls and columns to foundations
• Wire Loop Box to connect walls together
• Precast Coupler to connect precast elements
• Dowel Systems for connecting slabs to walls
Moment® Grout Coupler
Moment® Wire Loop Box
They are usually used to connect 2 adjacent precast panels together, where the interlocking rebar and wire loops provides robustness in the event of an Earthquake to ensure that grout degradation would not result in complete collapse.
Moment® Connection Loop
In order to connect 2 precast elements, both precast elements has to be cast with the Moment® Connection Loop at the wall. A rebar will then be inserted through the intersection of 2 loops. After placing the rebar, the gap between the precast elements will need to be grouted using a 40Mpa or 70MPa non shrink grout depending on the application. Material strength of the Moment® Connection Loop is 1770N/mm and complies to EN12385-4:2002+A1.
HEK Precast Coupler
Cast-in DEMU Fixing anchors i.e. T-FIXX®, bolt or bar anchors transfer the tension and shear force into the precast element.
The main advantage of the system is the fast and efficient positioning of precast elements. The connection can be subjected to load immediately after installation. This results in a substantial improvement in construction time.
But by keeping the grouting to a minimum, one such technology – Invisible Connections – has revolutionized the use of precast all throughout Northern Europe; it is a patented system, with its origins in Norway, to connect precast concrete without use of corbels or steel angles, and is used extensively throughout Europe due to the independently tested and certified European Technical Approval (ETA ) that provides engineers with peace of mind about the capacities.
The product range of Invisible Connections consists mainly of TSS Telescopic Stair Connectors & BSF Telescopic Beam Connectors.
Another topic relating to Invisible Connections will be covered as a future topic in our Academy site.
There are many good technologies available, but a dependence on local testing and local reference projects will hinder and slow down their introduction. An increased readiness to accept the certification schemes for prequalification that exist overseas such as ETA and ICC certification where appropriate, will mean that the technologies can help keep pace with the requirements of the precast industry.
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