The first set of concrete cylinders was prepared with treated aggregate 
rinsed in the acetone-water solution, which had been selected as the 
best solvent. After 6 months of exposure in Port Hueneme, the compressive 
strength of treated cylinders was 4,200 psi, while that of untreated 
controls was 5,140 psi. 
The 28-day compressive strengths of cylinders from set no. 2 are 
compared below to those duplicates from this set exposed 9-months in the 
ocean: 
Compressive Strength 
(psig) 
Treatment Designation 28 Days 9 Months 
Control UT 35 710) 6,710 
Pea gravel PG 6,080 
TBTO TB 4,840 6,090 
TBTO/creosote KR 3,200 3,840 
The 9-month exposure measurements were for the Key Biscayne cylinders. 
The third set of concrete specimens had 28-day compressive strengths 
as follows: 
Treatment Designation 28-Day Compressive Strength (psig) 
Control V4 4,660 
TBTO v1 6,010 
TBTO/Cu,,0 V2 5,360 
Cu,,0 v3 5,330 
The compressive strength of the fourth set of cylinders was not 
determined. 
Corrosion of Simulated Reinforcing Rod 
The loss in weight of nails used to simulate reinforcing rod versus 
time is presented in Figure 7. All of the candidate antifouling chemicals 
evaluated in this test inhibited rather than accelerated the corrosion 
of the steel except cuprous oxide, and that only when employed by itself. 
The presence of TBTO, creosote, or a mixture of these compounds caused a 
significant reduction in the rate at which the steel corroded. 
After 446 days exposure, the percentage of weight loss of the 10 
replicate nails exposed to the various concretes was: 
