Chose alternate sections quickly and easily
Also, if you are thinking of replacing one section with another, you can easily compare, LxW , Weight Per Meter, Section Modulus.
Author: Pon Dhileepan
Lysaght Zed sections feature one broad & one narrow flange, sized so that two sections of the same size fit together snugly, making them suitable for lapping.
The table below from the lysaght catalogue clearly shows the difference in sizes of each flanges.
The purlin bolts are always placed equidistant from the centre & hence the steel modeller does not have to worry about whether the broad flange of a purlin comes at top or the narrow flange. The broad & narrow flanges will be placed alternatively at the site. This is the case for almost all the times.
But very rarely, there might be additional bolts/holes at the top flange or bottom flange and the steel modeller has to consider modelling the purlins with their exact orientation i.e, whether broad flange of a purlins comes at top or the narrow flange.
For instance, the below design demands for M12 bolts or hook rods from the top flange of the Zed purlin to support the nearby gutter. Hence the modelling has to be precise about the broad flange & narrow flange for each purlin in a continuous row.
TEK1 done a detailing work for the link bridge.The complication of this project is site measure. We have to co ordinate with the existing building site measure to finish this work.Most of the structural members are connected to the existing concrete.We have coordinated with site surveyor & got the dimension we want to connect the steel.
TEK1 completed this job without any mess.We have provided a good info to fabricator as well as erector to finish this project smoothly.
Precast erection procedure having the set of sequences. When the panel is installed on the slab, props are fixed to stable the panel, then panel was unhooked from crane then the temporary stich plate or stich angles are connected to the next panel through cast in ferrule, which is casted on the precast panel.
The temporary connection is additional support for the precast panel for until grouting the grout tube & slab were connected to the particular panel. The panels are easily leveled up with respect to the connected panel. Minimize the no of brace connections. Easy to maintain the panel gap.
Based on the position of panels & face of the connection it is classified as below,
1. In-line stich plate:
When the panel are next to each other the temporary connections are made by the straight stich plate with ferrule as mentioned below picture.
2.Internal Stich angle:
When the panel is perpendicular each other and inside corner is access to perform the connection, the internal angle stich angle is being used.
3. External stich angle:
When the panel is perpendicular each other and outside corner alone is access to perform the connection, the external angle stich angle is being used.
4.On edge stich angle connection.
Some cases, same level panels one is erected on top of slab and another one is located on ceiling level is supported by on-edge ferrule mentioned as below picture.
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Precast panels are ready made concrete element, which is the part of the building as structural as well as façade panels, which required the surface finish as per the customer or Architect requirements. Various type of finishes are used on the both side of panel and edges according to where the panels are positioned on the building.
Due to the process of precast manufacturing, the finishes are made by replication of table on the one side, and the other side our traditional or conventional methods are preformed after pouring the concrete. As per concern of precast finishes, its classified as
2. Table Finishes.
Every multi story buildings typically need the loading bay or hoist for each and every level during construction. A loading bay or loading dock is an area of a building where goods are loaded and unloaded to it from vehicle or site. On hoist or loading area of façade walls is being unbuilt up to end of construction. Final stage of construction only it needs to be built. Refer below picture for different types of loading bays are highlighted.
If the rest of the building is constructed by the precast, the hoist area also needs to be covered or fixed by precast panel. This type of covering panels are named post fix panel. Which means the panel will fix on the existing structure after completion of required task.
These post fix panels have different type of erection procedure, connection details compared to the all-other precast panels.
Propping Method for Post Fix Precast:
The temporary bracket connection between panel and to the slab need to be done at the top of the panel. The rest of the panel hanging below slab where braces are connected to plumb the panel as well as support. That the brace is anchored below level slab. The bottom of post fix panels is connected with dowel & grout tube arrangement to the below level precast panel. Refer the propping snap.
Permanent Connection of post fix panel:
The grout tube with dowel connection between the panels are only resist the horizontal movement, the additional permanent connection is made between panel and the slab through cast in plate and weld on site at both top and bottom the slab. The structural connections details are need structural engineer approvals. Refer below picture for typical connection details.
