Monday, March 3, 2008

RE: Concrete exposed to seawater

Check out:
UFC 4-151-10 General Criteria for Waterfront Construction http://www.wbdg.org/ccb/DOD/UFC/ufc_4_151_10.pdf
UFC 4-152-01 Design: Piers and Wharves http://www.wbdg.org/ccb/DOD/UFC/ufc_4_152_01.pdf

Regards,
Harold Sprague

Subject: RE: Concrete exposed to seawater
Date: Mon, 3 Mar 2008 12:17:40 -0700
From: William.Sherman@CH2M.com
To: seaint@seaint.org

I did find that the AASHTO Bridge Specifications do include specific requirements for "direct exposure to salt water" (4-in) and for "coastal" exposures (3-in).  (Could be reduced 0.5-in for low w/cm ratio.)  But let me be more specific regarding my questions:
 
If a performance specification for a non-bridge, coastal structure for a design-build project states that the design shall be in accordance with ACI codes and standards and with the recommendations of ACI 201.2R and ACI 222R, what are the minimum requirements for concrete cover for seawater and salt air exposure?  I did find that ACI 201.2R, Section 4.4.3, recommends a minimum of 3-inches of cover for "severe marine exposure"; but Section 2.4.3 references ACI 357R (for offshore concrete structures), which recommends 2.5-in for splash zones.  There is less discussion of exposure to "salt laden air" for structures near the coast in ACI 201.2R and ACI 222R, but ACI 357R does recommend 2-in cover for the "atmospheric zone not subject to salt spray".  I am a bit surprised that there is not more explicit direction in ACI and PCA documents on this subject, as such structures are not uncommon.
 
Bill Sherman
CH2M HILL / DEN
720-286-2792
 

From: bart@nbse.com [mailto:bart@nbse.com]
Sent: Saturday, March 01, 2008 2:43 PM
To: seaint@seaint.org
Subject: Re: Concrete exposed to seawater

You can also go to cement.org, and the standard specs for DOT's  for CA, FL, OR or WA which I believe are available online....also make sure you use a well graded aggregate mix as you want as much of an even distribution of cement paste that you can achieve, without a lot of cracking.....

----- Original Message -----
From: William.Sherman@CH2M.com
To: seaint@seaint.org
Subject: Concrete exposed to seawater
Date: Fri, 29 Feb 2008 16:17:06 -0700

Do any ACI codes or standards specifically address concrete cover requirements for concrete:
 
a. Directly exposed to seawater.
 
b. Exposed to salt laden air (coastal structures not in direct contact with seawater).
 
I am aware of some discussion in some ACI guides and commentaries and some requirements in European standards, but I am looking for "mandatory language" documents in the U.S.
 
Bill
William Sherman - CH2M HILL / Denver
Principal Structural Technologist
Structural Global Technology Leader - Water Business Group 
720.286.2792
 
 
 


Bart Needham, SE Principal, nbse associates, inc. civil & structural engineers Office 206-780-6822 Office 805-452-8152 Fax    206-780-6683 Fax    208-693-3667 Mobile 206-300-2346  Office locations: 629 State Street #230 Santa Barbara, CA  93101  205 Fairview Lane Suite 100 Paso Robles, CA  93446  365 Ericksen Ave. NE Suite 328 Bainbridge Island, WA  98110  Mail and Deliveries: 321 High School Rd. NE Suite D-3 PMB 216 Bainbridge Island, WA  98110


Connect and share in new ways with Windows Live. Get it now!
at