cement, its resistance can he further enhanced with addition of air entrain- 

 ing admixtures. 



(4) Soil Cement. Soil cement is seldom exposed to severe tempera- 

 tures and ice as these conditions require an increase in cement content 

 resulting in a substantial increase in cost and may eliminate the considera- 

 tion of soil cement as a construction element in this environment. For 

 severe exposures it is important to note that an excess of cement is not 

 harmful but that a deficiency of cement will result in inferior soil-cement 

 resulting in cracking and spalling. 



(5) Sulfur Cement Concrete and Grout. Sulfur cement concrete and 



< , — i — o 



grout because of the low melting temperature of sulfur (130 Celsius) will 

 deteriorate at elevated temperatures. Low temperatures have little effect 

 on this material. 



f . Marine Organisms . 



(1) Bituminous Concrete . Bituminous concrete is subject to 

 deterioration from crustaceous organisms as it is comparatively soft as a 

 coastal environment construction material. When used as a binder with other 

 materials such as large stone, this type of deterioration has little effect 

 on the structure. 



(2) Preplaced Aggregate Concrete. Preplaced aggregate concrete is 

 not affected by marine organisms. 



(3) Portland Cement Grout . Portland cement grout is not affected 

 by marine organisms if properly mixed and placed. 



(4) Soil Cement. Soil cement is not usually exposed to an environ- 

 ment containing marine organisms. When it is, many organisms will become 

 attached to the rough surface of an exposed soil cement surface and cause 

 spalling. Boring animals can penetrate the surface but apparently do not 

 find it a desirable environment; therefore it is not a common condition. 



(5) Sulfur Cement Concrete and Grout . Sulfur cement concrete and 

 grout has not shown any deterioration from marine organisms; however, due to 

 the limited experience with this material, long-range performance experience 

 is not available. 



g. Periodic Wetting and Drying . 



(1) Bituminous Concrete . Bituminous concrete surfaces may tend 

 to develop fine cracks or alligator patterns on exposed surfaces when 

 subjected to alternated wetting and drying. Such cracks seldom develop any 

 signficant depth in asphalt concrete and are not serious in coastal struc- 

 tures . 



(2) Preplaced Aggregate Concrete . Preplaced aggregate concrete is 

 subject only to the same action as Portland cement concrete, i.e., the 

 formation on the surface of "D cracks" usually in random patterns. These 

 are normally restricted to the surface and do not contribute to serious 

 deterioration. 



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