Lateral loads on immature concrete

[ozziz]

Appreciate views,information and opinions on immature concrete subject to lateral loads.

The contractor has to install steel tubular piles for construction of wharf into rock sockets. The concrete specfied is 40 MPa at 28 days strength. The contract calls for the piles to be temporary braced. But the contractor wanted to release the braces after 7 days when the strength is around 25 MPa. This means the concrete is immature and has not reached its 95 % full strength. Question is will the concrete pemanently deformed if the lateral loads such as wave, current is excessive? Where can I source inform on strength of immature concrete?

 

[SlideRuleEra]

American Concrete Institute address loads on immature concrete in their document ACI-347, Formwork for Concrete.
Typically, problems occur if the loads cause cracking.

Google Books has a preview of ACI-347. Fortunately, Section 5 - Loads & Pressures is complete in the preview. See the information starting on Page 5-18. Here is the link

http://books.google.com/books?id=0G...X&oi=book_result&resnum=1&ct=result#PPT104,M1

For your situation, of course the easy answer is to tell the Contractor "NO". But, IMHO, that is not what engineering is about. Take a look at the live loads that the wharf was designed for (perhaps ship mooring or impact?). If those loads are large compared to wave, current, etc. and will not occur while the concrete is curing, perhaps you can consider allowing the Contractor's request.

If your look at the numbers is encouraging, have the Contractor submit to you a detail plan of exactly what he plans to do (prepared by an independent Engineer, at the Contractor's expense). If the plan is reasonable, accept it.

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[ozziz]

SlideRuleEra

I look up at the reference Formwork for concrete as recommended, it does not mentioned about loadings on young concrete. The book is more towards formwork and concrete pressure on formwork

 

[SlideRuleEra]

Ok, you could try "ASCE 37, Design Loads on Structures During Construction".

I have not seen this document, so cannot say if it addresses your concerns. Here is a link:

https://www.asce.org/bookstore/book.cfm?book=4242

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