Prof Thomas Murray passed last week at age 84.
I attended several of his AISC "virtual" seminars. Always a very professional researcher and presenter.
I am guessing several "Hokies" enjoyed his engineering classes and lectures.
A memorial is here: Modern Steel Link
I have to load test (in the field) some old (40+ years old) high-tensile post-tensioning components to a force not to exceed 33 kips (about 150 kN).
The post-tensioning element is made up of 7-wires to form a 1/2" nominal diameter strand, of 270 ksi tensile capacity. Outer six-wires are...
According to a Google source, carbon steel (type AISI 1010 steel) has a resistivity: ρ = 14.3 x 10-8 Ωm at 20 °C.
Does the resistivity of carbon steel vary significantly depending on its carbon content, heat treatment, relaxation properties etc?
I am trying to determine the electrical...
I have designed and detailed a 6 foot tall steel testing frame that shall be used for static testing of post-tensioning strand & wire tendon assemblies. Simple set up of multi-wire or multi-strand vertical tendons, concentric within a steel frame.
I have an immediate need for a 200,000 lb.f...
I am trying to find a traceable source of mechanical properties vs hardness for AISI 4140 cr-moly steel that is quench and tempered to achieve Rockwell C hardness of 40.
I have this table of properties from a unreferenced paper:
I understand it was derived from the 1965 SEA Handbook and...
I have a project that may require the use of compacted 7-wire prestressing strand. I have experience with 1/2" (12.7mm) and 0.6" (15.2mm) diameter 7-wire prestressing strand, but little with compacted strand.
Does any one know if after regular 7-wire strand is manufactured, does the strand...
I have a project constructed with structural steel that is existing and without original structural drawings (more than 50 years old), so we do not know too much about the mechanical properties of the steel used.
We propose to take field coupon of selected members (mainly W sections) and have a...
Last week Saturday there was a sizeable concrete placement close to a project I am working on - more than 700 cy - and being nosy I decided to swing by and take a look.
RC foundation slab with thickened edge beams for a new industrial warehouse lease complex by a local developer, who has many...
I live/work in the structural 'world' and need some assistance from EE's.
I work with unbonded post-tensioning strand tendons - basically high-tensile 7-wire carbon steel strands that are 'insulated' with HDPE sheath along there continuous length, and placed inside concrete slabs and beams and...
I recently repaired a 60 ton center-hole hydraulic ram (for post-tensioning bar stressing), and to verify that the new seal kit was indeed holding I did a recent load test. I grabbed a 1" dia x 105 ksi F1554 galv anchor rod with heavy hex nuts and washers (I usually use a 150 ksi PT bar but not...
I recently extracted 4 failed 7-wire steel strands from a post-tensioned concrete parking/plaza deck.
Strand tendons are the typical MUTS 270 ksi, 1/2" diameter, greased and sheathed, and the structure is 20 years old, and otherwise in excellent condition with meticulous maintenance etc. The...
I have a new aggregate conveyor (not yet installed) that has to be lengthened with a new vertical support frame to be added. Due to some site obstructions the new frame will be asymmetric. The exterior geometry of the frame is somewhat fixed, but I can 'play' with the internal bracing...
I need to regularly calibrate 10,000 psi pressure gauges (hydraulic stressing applications).
I want to do this now in-house and want to know if anyone has experience with RALSTON or FLUKE pressure gauge calibrators with their respective manual hydraulic pumps.
Specifically, I am looking at...
I have to load test existing unbonded post-tensioning tendons to an existing buildings floor system that was built 50 years ago. I do this regularly - usually to 1/2" diameter 270 ksi 7-wire stranded tendons - but this one was built using 1/4" dia high-tensile wires with "upset" (button-heads)...
I have a 1920's structure with concrete repair requiring possible rebar splicing due to corroded rebar. Existing rebar is deformed with square section, and shall be coupled to new round deformed rebar.
Has any one used the NMB grouted splices or shear-screw coupling for such applications...
Trahair's name/research has come up here on E-T over the years with LTB and related issues. Sad to be notified of his recent passing:
I enjoyed his lectures and his lecturing style.
I was doing an online search a few days ago (engineering-related search on unbonded post-tensioned concrete tendon failures) and deep within the search results I found a link and PDF document (from a Canadian structural engineering consultancy web site - FIRM 1) that includes a photograph that I...
I hang out in the structural forums, so forgive me with this probably simplistic question for you EE's.
Our washing machine (front loader - which I dislike, but do not really wish to replace at this time - it is only 6 years old) recently stopped working with a 'LE' code. I found the problem -...
For those that are ACI members and missed ACI's January announcement (if you are like me you get bombarded with too many emails) then you can participate in free on-demand webinars and obtain PDH's: Link
The MyCourses portal keeps track of your courses, certificates, transcripts, etc., similar...
