It is recommended to add water to fresh concrete for 7 days to keep it moist and effect good curing. What if it's not done. Can one add water to the concrete 2 months later to continue the chemical reactions that could have stopped because of insufficient water during the 7 days curing period...
I need to remove a section of epoxy from a column and need feedback from those
with experience.
Epoxy seem to drill softer than concrete. Is it normal? This means one can just
drill it around rebars to separate the epoxy from bars? What else do you suggest?
Picture of the column with epoxy is...
Something I don't quite get even after reading the following portion many times (see My questions below)
http://mmgrouting.com/foundation.htm
"Epoxy grouts cannot be reinforced with rebar like cementitious materials because of the differences in the thermal coefficient of expansion and modulus...
3000 psi means concrete has compressive strength of 3000 psi. What if the load is very light, like using only the concrete 200 psi. As the load gets heavier, would the column compresses more (and shorten in length in say very tiny 0.001 mm)? Or is there no change in concrete column length due to...
I'm just wondering while researching about non-shrink grout. Can one make an entire beam or column using non-shrink grout instead of poured concrete? What is its disadvantage aside from price? What is the equivalent aggregate sizes of non-shrink grout, 3/4" or 1" or is it equal to ready-mix...
Is epoxy mostly for waterproofing or could it be used for structural repair? if the latter not possible, what properties make it not possible since some epoxy are rated as 20,000 psi? Are there different kinds of epoxy? Who have used these? thanks.
How often do you encounter columns with misaligned main bars, for example, one corner has the bar 30mm from the corner while the other corner has bar that is 50mm from the corner. Originally they should be 40mm (meaning the surrounding concrete cover is 40mm), but in actual construction, it...
when you are pouring concrete section by section in a column, which section is allowed partial pour in your practice? Can you do it at middle of column? I know the best is to pour the entire columns at once but the problem is you can't insert the vibrators thru the upper floor column-beam joints...
a building has columns with ties distance 100mm (4") apart with close ties. But in the construction in the ground floor columns, one of the hooks are not bent 135 degrees but just 90 degrees (it is corrected in second to fourth floor which is the maximum storey). What kind of column retrofit can...
for close ties with ends bent at 135 degrees, what if the ends are shorter and don't have the required ten times diameter? how serious is this in your experience and would it open during seismic activity? what standard or development length do you use for the ends (for example 10x bar diameter...
In upper floor, the column is 3.2 meters and the formworks would be about 3 meters and they would be poured at once. Is this not too long and can cause honeycomb at the bottom? But renting pumpcrete is expensive if only say 2 meters would be poured, what do you think? Is external vibrator...
The usual procedure is to first put compacted soil and put the tie beam on top of the compacted soil so the weight would bear on the soil and not the columns. But in one of the tie beams in the constuction site, the tie beam was poured with concrete using just wooden support (and not soil...
Imagine there are two vertical girder rc beams on left and right. And in between them is a secondary beam with its top bars over the top bars of the girder beams. This means the secondary top bars are higher than the girder top bars. If you use 40mm concrete cover on the left and right girder...
Do you have sites where all of this are shown in details? Two long span slab 5 meters length are to have continuous bars running at bottom and top. I pressume the splicing of those bars is similar to splicing in beam where the top continuous bar are spliced at center, but can you splice the...
The design of top bars at support of a 300mm width by 500mm depth rc beam has 7 bars. Is it recommended to put all 7 bars in one layer (top most) and bundled together in two's or distributed in two layers? What do you usually do in your practice? I think distributing it in two layers can...
Do you in practice actually have to continuously wet or put water newly set concrete in mat foundation, rc columns, or beams, for how long? What happens if you don't?
