We are designing a temporary epoxy adhesive anchoring system to prevent a distribution beam rotation against unbalance concrete pouring. The main function of this distribution beam is to support the temporary form work and cap concrete self weight of a pier cap. The only way for these beam to rotate is when they are pouring the concrete in the form work they do it in such a way as to unbalance the load and create this rotational effect on the beam. We are using 1-1/4 in threaded rod with HIT-HY 200 Adhesive anchoring system and an embedment of 11.25". The two bolts are spaced at 34 inches from each other, but on the load adjustment factor table , the spacing factor provided is 0.94 at 30" and 1.00 at 36". My questions is , since we there is no spacing for our actual spacing of 34", can we interpolate for a temporary work ? or how have you handle temporary works factors ?
Joseph,
As seen in Footnote 1 of the load adjustment factor tables "Linear Interporlation is not permitted" for intermediate spacing, edge distance, and concrete thickness values. In these instances, designers will either (1) utilize the PROFIS Anchor design software (https://www.hilti.com/software/software-for-fastening-systems/r2755) to determine the capacity of the anchor system, or (2) utilize a the lower of the two reduction factors (in your case 30") to perform a conservative calculation.
Let us know if you have any additional questions.
Regards,
Bryan