Recent content by gosai

Thank you so much to Ron and SlideRuleEra for sharing your knowledge and experience. This will help me a lot to continue our work.

Thanks Ron They have only three hours window between pouring concrete and train service starts. Use of high early concrete is not permitted.

Caissons are between the tracks and contractor work during night hours when train traffic stops

How long will it take for concrete caisson to develop enough strength to resist vibrations caused by train traffic?

Specified strength is 4500 psi with 5 to 8 % air

The sidewalks has been poured 3 to 4 years back. Recently the sidewalk concrete spalled at several locations. In our opinion the spalling is a problem related to finishing and workmanship. The contractor is blaming deicing chemicals for the problem. Could any one provide more information on...

Thanks for the reply, Let me attached the first photo to show how the crack developed. One of the sub trade also noticed water dripping from the pipe conduit. The temperature was below 0 for some days and then in +. Ron, the pier was poured up to underside of the base plate elevation. The...

I have a job site where debonding of concrete occured on a concrete pier. The concrete was poured 7 months back. recently a big visible shear crack occured. Two photos are attached. I am not sure why this happen? Is any one can provide causes for debonding of the concrete and recommendation to...

Thanks to everyone for helping me. Epoxy coating will be placed on the floor after treating all cracks by sandblasting and filler.

The specified slump was 5". No vapour barriers underneath. Fibres were used to prevent cracking.

A slab was poured in July 2012 on granular A materials. The granular 'A' materials was compacted to a 98%. The saw joints were placed at a distance of 10' 6". The average measured thickness of the slab was 6". Approximately after 8 months of the pour the cracks appeared on the concrete slab. The...

Could any one help me in selecting concrete strength for Head Walls of SWM Pond? Does it require air content?

Jed, It is between 1 and 28 days, the final test results show shrinkage but few readings as i said show slight increase in length (between 4 and 7 days). One specimen show 1 mm increase and other specimen show 1.5 mm increase. Overall results of shrinkage looks fine. Just to know is it possible...

Hi all, I am involved in pumping station project and during concrete pour for slab on grade for reservoir we cast set of prisms to test Linear Shrinkage. I received test results from testing company. The test results show shrinkage around 0.044, which is slightly over the specified limit in the...

At one of our project contractor wants to use 2% Krystol Internal Membrane (KIM)as an admixture for water proofing purposes. The information for product is uploaded. I never came across using this type of product. Is there someone who knows anything about such products and its suitability to use...