Drill a Precast Beam

Is it like SpanCrete Beam?

I would talk to them or whoever cast it, You do not know what's internal or the makeup of the beam.

If it is pre-stressed, when you drill, try to drill through one of those rods running the length of the beam, now that is an eye opener!

SERIOUSLY, don't drill until you have contacted the manufacturer.

Price of a phone call = $

Price of a new beam = $$$$$$$$$$$

Price of potential liability if the beam fails post drilling and construction = $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

Hy Guys J

lyn : thanks for the drilling info.

phoenix911 & KJK : I've just contacted the manufactured of the pre-stressed beam. He said it's possibile, far from the cables (min 20 cm - 8 inch). Wise advice !

I have to connect the beam to the column in order to avoid seismic risks after in 2012 Emilia quake. I can't use reinforced fiber 'cause the moist environment (industrial laundry).

Thank you all :)

[URL=http://imageshack.us/photo/my-images/689/201210101.png/][IMG]http://imageshack.us/a/img689/1749/201210101.png[/IMG][/URL]

[URL=http://imageshack.us/photo/my-images/689/201210101.png/][IMG]http://imageshack.us/a/img689/1749/201210101.png[/IMG][/URL]

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Hy,

I wanna post an image but I don't know how?

Can you help me? Thanks :)

Seriously, hire a Structural Engineer to design the connection. Typically, one normally doesn't drill through a prestressed precast concrete to attach it to anything, unless you know EXACTLY where the prestressing wire strands are located within it. You do not want to drill or cut a strand, otherwise you might as well throw out the beam because it will be useless and structurally unsound.

What type of column, steel or concrete? Usually a structural steel angle (beam seat) is used to support a beam or a prestressed precast concrete (PPC) beam or plank. This seat must be secured to a concrete column with expansion anchors or a concrete corbel......be careful of hitting internal reinforcement steel in the column! If it's an existing steel column, then the beam seat must be field welded to the face of the column, or the column drilled to accept structural bolts.

Regardless of the type of column, the underside of the ends of the precast beam must have a cast-in-place steel plate anchored back into the concrete so that the beam can be field welded to the steel beam seat. You should also install a smaller structural steel clip angle at or near the top of the beam to prevent it's rotation (twisting) while under load.

I cannot stress this enough, for safety sake hire a qualified Structural Engineer......for peace of mind and as a cheap insurance policy that the design is structural sound and safe!

Hy CaptMoosie,

I've asked to manufacturer to know exatly where the prestressing wire strands are located. I wanna post an imagine of the joint but URL code doesn't work. Can u help me? :)

That is a GA, but,

If you want to get anywhere, the structural Engineer should be from the manufacturer of the precast beam.

Having worked in installing components and modifing walls, with penatrations. An outside structure engineer will not get you results in a timely manner.

Again, the structural Engineer should be from the manufacturer of the precast beam.

just from my experience.......

That is a GA, but,

If you want to get anywhere, the structural Engineer should be from the manufacturer of the precast beam.

Having worked in installing components and modifing walls, with penatrations. An outside structure engineer will not get you results in a timely manner.

Again, the structural Engineer should be from the manufacturer of the precast beam.

just from my experience.......

Hy Phoenix911,

it's not possible, but I have the manufacturer engineer authorization and the wires position.

See: http://imageshack.us/photo/my-images/689/201210101.png/

thanks :)

Plan 'B' is good enough.........

Good luck

Hy, do you mean the right part of the drawing or the manufacturer autorithation? :)

I wish my command of the Italian language was good.....it isn't, and almost non-existant. My Grandfather from a small mountain village outside Naples didn't teach me it! So, I've tried to guess what some of the words are.

I really don't like either scheme, especially if the structure is in a known seismic zone.

The left scheme is somewhat okay, but needs to be heavily modified from a structural seismic engineering standpoint. It is in my Professional opinion, structurally insufficient in regard to seismic resistance. Is the beam in question actually a concrete truss, as shown in the drawing?

Okay, has the beam manufacturer's engineer actually design the connection for seismic loadings? It doesn't appear so to me.

Instead of opposing steel channels used in the connection, the top of the column (concrete?) should be totally wrapped (continuously) with a series of structural steel plates all welded together. The plates, and anchor bolts (sizes and number), have to be calculated to withstand the seismic load, which has to be determined as well. the anchor bolts on both sides of the column cap should be spread out enough to prevent overlapping shear and tensile pullout zones, thereby dictating the depth of the wrap-around structural steel plates.

The same steel reinforcing and anchorage should be installed at the ends of the precast concrete beam.....all of this reinforcement must structurally resist the seismic lateral loadings that will occur back and forth (like shaking). You must be able to transfer the loadings into the top of the columns to be effective. You must also prevent the precast beam (@ roof?) from toppling over onto one of it's side from the from shake. You could utilize pinned earthquake dampeners that are properly designed, thhat allows the beam to move back and forth independently from the columns, but also prevents the rotation of the beam in respect to the columns. Again, a structural engineer should design this, who is licensed in Italy. I cannot do it for you, even if I an a New York State Licensed Professional Engineer and hold SE credentials.

I sure hope that both the concrete beam and the columns have been designed properly for seismic events and applicable building codes!

Ohhh my, what a can of worms we have here!

Are you the Contractor fixing this mess??????

use clip angles. that's angle iron that's wide and long enought to support a maximim load. consider the type of anchor bolts you're planning to use. one cip angle top and bottom. drilling ito the side of the post and beam will eliminate the possibility of weakening the pre-cast un less you drill though a rod. move the hole if you hit a re-bar.

i would recommend a hilty hammer drill with a good concrete bit. if you [hit a re-bar, move the hole].

If planned properly,During casting they should have included 2 pvc sleeves to match the dia of bolt to be inserted at both ends to fix it to the column.

Hy CaptMosie, DirtieDuck and Pnaban !

The drawings is from the gov. instructions for the fast rehabilitation of prefabricated one storey industrial buildings ( a lot of them have fallen down in Emily !). Infact there is no connection between prefab. colums and beams. So we wanna recreate a hinge, no moment transmitting, in order to avoid relative movements. The same with the roof elements.

In my case, the columns are made of reinforced concrete and the beams are of prestressed concrete. I welcome any advice (and drawings) thanks!

if i understand ur situation, slotted holes in bottom clip. lose the top clip..i've used teflon,, "two layers", at expandion joints that served the same purpose,.and shoulder bolts on the bottom clip for movement.

Hy Durtieduck, can you show me what you mean? Thanks