Quade999
Civil/Environmental
- May 29, 2020
- 61
In AASHTO it gives two equations for determining the stress that can be used in design of prestressed strands that are extended past the girders and into a continuity diaphragm with a 90 degree bend. See below.
In the equations it shows that the stress is a function of the total strand length minus 8 inches. Below it says that the strands must project at least 8 inches before they are bent.
My question is if the equations need to be adjusted if the distance before the bend is longer than 8 inches? See below example where strand extends 10 inches before being bent upwards. In this case would the equation be updated to fpsl = (30"-10")/0.228, or would it remain the same as in the code with fpsl = (30"-8")/0.228.
I think the equation should remain the same as presented in the code regardless of the distance before the bend as it specifies that ldsh is the total length the extended strand which includes the total horizontal and vertical distances. But the 8 inches in the equations and the 8 inches projecting requirement throw me off.
In the equations it shows that the stress is a function of the total strand length minus 8 inches. Below it says that the strands must project at least 8 inches before they are bent.
My question is if the equations need to be adjusted if the distance before the bend is longer than 8 inches? See below example where strand extends 10 inches before being bent upwards. In this case would the equation be updated to fpsl = (30"-10")/0.228, or would it remain the same as in the code with fpsl = (30"-8")/0.228.
I think the equation should remain the same as presented in the code regardless of the distance before the bend as it specifies that ldsh is the total length the extended strand which includes the total horizontal and vertical distances. But the 8 inches in the equations and the 8 inches projecting requirement throw me off.
