ESCSI Weekly 10: Remembering U.S.S. Selma
Expanded Shale, Clay and Slate Institute
ESCSI is the association for manufacturers of rotary kiln-produced expanded shale, clay and slate lightweight aggregate.
Expanded shale, clay and slate (#ESCS) #lightweight #aggregates have numerous applications in #concrete #structures, including #buildings, #bridges, and #marine #structures. The U.S.S. #Selma, launched in June 1919, was the second and the largest #concrete #ship constructed in the United States. The ship had a 7,500 ton tanker with 434 ft length, 43 ft beam, and a draft full cargo of 26 ft, constructed from 100% #expandedshale #lightweightaggregate #concrete.
The history of #slump cone test, ASTM C143 Standard, begins with U.S.S. Selma as engineers needed the means to control the #workability of #concrete filling congested #steel #reinforcement grids. The construction used 7,350 tons of expanded shale #aggregates with 69 and 44 pounds per cubic feet density for fine and coarse materials, respectively.
The ship, one of the 104 #lightweight #cocnrete ships built in the United States, served as an oil tanker until it hit a jetty and retired in #GalvestonBay, where she resides today. Since then, the ship has served as a valuable specimen to help engineers understand the #durability of #concrete in #marineenvironments. Several series of tests conducted in 1953, 1980, and 1990 have confimed the contribution of #ESCS to #concrete #durability and #protection of #steel #reinforcement disregarding the #corrosive #marine #environment.
Visit The Story of the U.S.S. Selma - ESCSI for more information about Selma! There are also additional information about #ESCS applicaions in marine structures in 4710.5-Performance-of-SLWC-in-a-Marine-Environment.pdf (escsi.org) and <https://www.escsi.org/wp-content/uploads/2017/10/4710.88-Evaluation-of-LWC-Performance-in-55-to-80-Year-Old-Ships.pdf>. Two additional information sheets cover bridges and marine structures using #ESCS in <https://www.escsi.org/wp-content/uploads/2017/10/4700.0-Building-Bridges-and-Marine-Structures-with-SLWAC.pdf> and <4700.4-Back-Up-Statistics-to-Building-Bridges.pdf (escsi.org)>.
Castrodale Engineering Consultants, PC
1 年This is a favorite story of mine regarding the history of lightweight concrete! The ship is still in pretty good condition - sitting in Galveston Bay. Search GoogleMaps for "SS Selma" and you'll find it (see attached screenshot taken after the search). It is certainly not a pile of rubble, but a well-preserved, 100-year-old ship! This ship is an amazing testament to the durability of well-proportioned and well-placed concrete. The bottom of the hull was only 5" thick, with the sides being 4" thick. And these had reinforcement in them, so in some cases, the cover was less than an inch, yet the reinforcement is still protected, even in this marine environment. I say that this is very convincing evidence that expanded lightweight aggregate, a porous rock, can indeed be used to provide durable concrete that can last over 100 years!