Title:
Lightweight Concrete for OTEC
Cold Water Pipes
Author(s):
A. Litvin and A. E. Fiorato
Publication:
Concrete International
Volume:
3
Issue:
3
Appears on pages(s):
48-55
Keywords:
compressive strength; concretes; con-crete
pipes; flexural strength; lightweight concretes;
marine atmospheres; research; tensile strength;
tests.
DOI:
Date:
3/1/1981
Abstract:
Development of a lightweight concrete suitable for use in cold water pipes of OTEC plants is described. Target properties for the concrete include a minimum design compressive strength of 4000 psi (28 MPa) and a maximum unit weight of 95 pcf (1520 kg/m3). Numerous trial mixes were prepared and tested to evaluate concrete properties obtained with available aggregates. Variables included very lightweight fine aggregates and newly developed admixtures. Tests were conducted to determine compressive, flexural, and tensile strengths as well as elastic and long term deformation characteristics. Water absorption was investigated under conditions corresponding to ocean depths up to 300 ft (914 m). The investigation led to a lightweight concrete with an air dry unit weight of 77 pcf (1233 kg/m3) and com-pressive strength in excess of 400 psi (28 MPa). Tests are continuing to determine concrete properties under combined stress conditions simulating those over the depth of the pipe.