At my personsl home I had my driveway sawcut into panels that measure 4.5'x9.75'. I know this goes against a recommended aspect ratio but I really like the design. The driveway is 4" thick and has 6"x6"-6/6 WWM. The mix is not a standard mix. It has a large does of colour and is an has an...
Our office policy is not to stamp calculations prepared by another engineer with our "submission stamp". We just review them and keep a copy of the calculations. Althought the stamp is a disclaimer to protect us, the owner of our firm tells us not too stamp the calculations with our stamp...
What does the term "Net" mean exactly in factored net geotechnical resistance? The geotechnical report is stating that the factored geotechnical resistance values given are the "net of the lowest surchange pressure on the soil surrounding the footing".
I don't have much experience dealing with...
I am working on a project that has a 4" Slab-on-grade with embedded in-floor heating tubes. The slab is 4000 psi concrete with fibre (the type that only reduces plastic shrinkage cracking). The tubes floated to the top of the slab (near the top of the slab) because the contractor was careless...
In a job I'm involved in, the contractor did not install the joists centred on the bearing plates. I guess the mason was not careful enough to locate them properly. Anyways, I was give the task to review the condition.
I believe that the pressure below the entire plate area will not be uniform...
In ontario & michigan, we specify that connection design is to be carried out by the steel fabricator and/or engineer retained by the steel fabricator. This is common practise here.
Is this common everywhere in the US? Why don't the design engineers always do the connection design?
I have a watermain that has to pass over a very large storm pipe. The thermal cover will be 3'. 5' of cover is required in our area. Should pre-insulated pipe be used or should styrofoam sheets be used above the pipe? Both?
Thanks,
PG
Jike,
This is an interior Slab-on-grade. Are you saying that the extra cement contributes to shrinkage? I thought that the extra water in a higher w/c ration contributes to shrinkage.
Our office standard is a w/c ratio of 0.45.
A ready mix supplier is telling my client that this will increase the chances of slab curling because the mix is more likely to dry unevenly (especially on a poly base). He also said drying shrinkage is more likely to be a problem. Finally, he said...
Does the existance of a top chord extension affect the forces in the web members near the cantilevered end? A simple analysis would suggest that the forces would be greater at the cantilevered end compared to a simply supported case of the same span and loading if there was no top chord...
When joists are parallel to masonry partitions should the bridging start and stop at the wall? Can it punch throught the wall and be grouted in place? what are the adverse effects of this? would a clip angle detail at the wall allowing vert. deflection be required? If less than 3/4" of max...
I forgot to mention that the 3 feet of masonry is above a poured concrete foundation wall. There is no bond beam specified below the window. The window jambs are reinforced with 1-#5.
Is the masonry below a window to be desinged as a cantilever? I notice that drawings from another consultant does not show this as reinforced. Could this be a mistake?
The situation I'm referring too is 3 feet of 8" block below a 12'-0" wide x 5'-0" high window.
If designed as a cantilever the...
Concrete block w/ brick veneer construction:
Is it common practice to use concave mortar joints on the exterior side of a concrete block wall? I notice that contracotrs usually don't rake these joint, they just make it flush. Is there a structural benefit for using concave joints on the...
I have used 18" dia. csp catch basins with cast iron grates in the past to drain playground area's combined with a cont. swale.
The grates are fiarly lightweight. Since a child could lift the grate it may be a safety issue. I was wondering if there was a typical way of preventing children...
I have a situation where I only have 12" of cover for a pcv pipe to catchbasin connection? The pipe is in a grassed area that would not expect any vehical loading.
Is there a problem associated with having storm pipes above the frost line? It's done all the time right?
Another problem I am...
Bonding agent may not normally be required but I want to ensure threre will be no problems. The slabs are already installed and have been finished smooth.
Are bonding agents typically used to bond the topping to the slabs? If so, what product is recommended. I've seen the topping crack and delaminate from the slabs a few times. In a current job, the concrete is the finished floor. The owner is concerned.
I want to use a bonding agent, WWM and...
JAE thank-you for the links. I found some good info.
My sawcut spacing will be 10 feet o.c. governed by the geometry of the classrooms.
I plan to use fibremesh 300 and specify that the WWM be placed 1/2" from the bottom.
Next job I will try a 4 1/2" slab with 2 layers of mesh.
