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Thanks again HotRod. I'm going to follow up with our state DOT. Their manual previously stipulated #4 spirals at 4.5-inch pitch, even if that didn't meet 5.6.4.6. A revision to the manual issued in January removes the #4x4.5 and simply requires compliance with 5.6.4.6.

Thanks for taking the time to reply HotRod10. When you say you ignore the requirement for drilled shafts, do you mean you ignore 5.6.4.6? If you design the shaft for the core concrete only, then what do you use as the basis for determining the required transverse reinforcement, since under this...

In AASHTO 8th Edition, Equation 5.6.4.6-1: rho=(4Asp)/(dc*s) >/= 0.45(Ag/Ac-1)(f'c/fyh) does anyone know for certain if the term "Asp" is meant to be just the area of a single bar of the size being used for the spiral, or is it twice that (i.e. "2 legs" as for shear reinforcing)? I have a 42"...

dik/hookie 66- I am going to take a look at it this evening and will check as many of those things as I am able to. The house is almost 100 years old and I think the corrosion is just the result of dampness and low concrete cover, probably some freeze the contributing as well. The space above is...

A friend's house has a garage with a concrete slab "roof" that is the floor of the living space above. House built probably in the 1920s. Most of the concrete cover has spalled off the slab soffit in lines following the rebar (orthogonal grid)and the rebar is obviously corroded. I haven't been...

Thanks so much bridgebuster!

Does anyone know if the recommended changes contained in this report have been adopted in the latest (7th) edition of the AASHTO LRFD Code?

BridgeEI, except that there are "zones" of the beam that are in compression. Why would they specifically call out a certain zone in a very specific manner if they intended the check to apply to the entire beam?

Question about the following provision of the AASHTO LRFD Bridge Design Specifications: Section 5.9.4.2.2 - Tension Stresses Table 5.9.4.2.2.-1 - Tensile Stress Limits in Prestressed Concrete at Service Limit State after Losses, Fully Prestressed Components Other Than Segmentally Constructed...

Question about the following provision of the AASHTO LRFD Bridge Design Specifications: Section 5.9.4.2.2 - Tension Stresses Table 5.9.4.2.2.-1 - Tensile Stress Limits in Prestressed Concrete at Service Limit State after Losses, Fully Prestressed Components Other Than Segmentally Constructed...

Section 10.6.3.4 of the AASHTO LRFD Bridge Design Specifications gives provisions for calculating sliding resistance of spread footings. For footings on clay, the specifications state that the sliding resistance shall equal the cohesion of the clay. This is my first use of this particular...

Section 10.6.3.4 of the AASHTO LRFD Bridge Design Specifications gives provisions for calculating sliding resistance of spread footings. For footings on clay, the specifications state that the sliding resistance shall equal the cohesion of the clay. This is my first use of this particular...

Section 10.6.3.4 of the AASHTO LRFD Bridge Design Specifications gives provisions for calculating sliding resistance of spread footings. For footings on clay, the specifications state that the sliding resistance shall equal the cohesion of the clay. This is my first use of this particular...

I would start with my local ready-mix plant, and ask them for strength histories on mixes using pea gravel (which is essentially aggregate smaller than 3/8" as I understand it, or an AASHTO #8 size). I think this is not an uncommon mix.

Thank you Kootk and bridgebuster for your thoughts. KootK, my thoughts were similar, so I am going to do some investigating to see if 1" studs and the proper equipment are readily available. Bridgebuster, the minimum transverse spacing is violated with 3 studs per row, and the longitudinal pitch...

Designing a steel beam vehicular bridge with a composite concrete deck. Initial run resulted in a W21x68 as the optimal section. However, shear stud design would require rows of (3) 7/8" diameter studs spaced transversely across the beam flange in some locations. The problem is that the flange...

dcarr- Thanks for your thoughts. The construction issues you mention are certainly things that we will consider in our final response to the contractor. The current design calls for rails as long as 38 ft. I thought I had read somewhere that standard lengths were 39 ft? f-d - a quick google...

fattdad- Are you referring to made in the US, or legally as in not stolen off some abandoned rail line?

msqaured- This is a tangent wall with plain concrete plug piers, so no lagging. We have done some additional research and decided to analyze it as a reinforced concrete section, utilizing bond stress for plain bars from the earlier ACI codes (1963 I think) to determine appropriate development...

I posed this question over in the Structural Engineering forum, but it occurred to me that perhaps the retaining wall guys might have had some first hand experience with this. In short we have a contractor proposing to utilize salvaged steel railroad rail as reinforcement for drilled concrete...