Hello
When pouring a basement wall of 300mm a problem occured in the batch plant which led to a concrete delay of 5 hours (half of the basement wall was poured). A cold joint was formed as noticed in the picture. The basement wall is resisting a soil pressure as well as a high water table...
Hello i have been searching posts in this forum about achieving a pinned connection in a beam column rc building.
Lets consider that i have a beam resting on a column at a roof level (or intermediate one).
I would like to design this beam in order not to transmit moments to the columns
Pinned...
Hello,
i have a preliminary pile load test where a central pile if being placed between 4 anchor piles. The designer is requesting a maximum load of 2 times the service pile load capacity along with a high strain dynamic test.
Generally, once the pile is subject to the ultimate pile load test...
I have a building which has already been constructed supported on piles and a mat foundation. The bottom of the raft is -1.9.
A watertank has been added recently. It is composed of one basement, ground and a roof.
The bottom of its raft is -6.4.
I would like to know what is the minimum distance...
hi,
the attached is a section of a parapet having a sharp shape in reinforced concrete.
Since this shape, whether it will be cast in situ or precast, I am afraid that one of the aggregates will settle at the top of the parapet and we wont get the desired shape.
In addition, the reinforcement...
The effects of temperature in ACI318-11 are left to the engineer judgment where the load combinations does exclude the effect of T.
When dealing with temperature on a roof slab where temperarure is considered due to the external exposure of the slab, what is the load combination including the...
Good day,
In a recent project, i had to deal with a typical basement wall extending 4 stories below ground.
The basement slabs were designed as a 300mm thick post tensioned plate.
The basement walls were designed in a separate model assuming pinned connection at the level of the slab.
Here...
Good day,
During the excavation of the piles under a bridge, one of the piles has been excavated and the machine broke down. Therefore, concretre couldnt be placed inside the pile for more than 24 hours. The machine will be fixed this night and today will be ready.
the pile is filled with...
Good day,
i am currently investigating the effect of temperature of a roof concrete slab exposed from one side to the outer environement (top face).
a thermal gradient will be developed of around 20 degrees. Since temperature will depend from the restraint in the slab and then, from the...
Hi guys,
when analysing a roof slab, edge columns will absorb unbalanced momenta which will result in a high reinforcement ratio since the compression carried by thee colums are not enough to counteract the tensile forces caused by the moment.
if we look at the below floors, reinforcement will...
Hi guys,
when analysing a roof slab, edge columns will absorb unbalanced moment which will result in high ratio of steel since the axial force will be small to counteract the tensile forces caused by thr moment. If we look at the below floors, the ratio will decrease since the moment will be...
Hi guys,
i have encountered the attached crack in some columns that have been poured 5 days ago. the crack is just at the top of the column which is the bottom of the slab since the column is stopped at the slab soffit.
Despite it is wide, I don't think it will affect the strength of the...
hi guys,
during an inspection on site, i saw that for all the cantilever beams, the hook for the stirrup was at the bottom of the beam not at the top. When i discussed why it was done that way with the foreman, he told me that is because a cantilever beam. I couldn't find anything in the ACI...
Good day,
For computing the second order effects, ACI 318-11 recommends 3 methods:
1-Non linear second order analysis.
2- linear second order analysis.
3- moment magnification factor.
For the moment magnification factor, we must uncheck the p delta option in etabs and run the analysis based...
Good day,
Regarding the anchorage of positive moment reinforcement, aci318-11 states that u need to enter the support by 150mm and the bar diameter should be small in order to satisfy an equation ( section 12.11.3) (ld <Mn/Vu + la). This option is disregarded if the reinforcement is anchored...
hi guys,
during the concrete pouring of a reinforced concrete slab (the volume poured was 650m3 - quite big), and after 14 hours of work, the pump machine stopped and the contractor didn't have any plan B since he didn't have any other pump to replace the old one. The remaining volume was...
hi,
regarding the development length for a bar in tension, and in order to be able to develop fy, i should anchor it ldh + the standard hooK which is 12db according to aci318.
if my column section is not big enough to ensure the ldh and i dont want to use the reduction factors allowed in the...
hi guys,
what is the acceptable range for concrete slump (during a slump test) for a ready mixed concrete with superplasticizer ?
the poured element is a reinfoced concrete element. Is 21 cm ok ?
THank you.
Hi guys,
i had an inspection on a site where they were pouring a concrete Slab. The concrete is C35/45. The concrete slump is reaching 21 cm although no superplasticizer has been added to the mix. it is too much since the allowable for slabs as i know is around 14 cm.
What is weird is that the...
Hello guys,
I have a reinforced concrete wall already built.
I want to anchor top and bottom reinforcement for the landing of a staircase. The wall is assumed as pinned and it is a non seismic region. What is the required embedment length for epoxy bars ?
Thank u.
