Aggregates, concrete

Jiir-entraining cements produce concretes that protect the concrete from frost damage. They are commonly used for concrete pavements subjected to wet and freezing conditions. Cement of low alkah content may be used with certain concrete aggregates containing reactive siUca to prevent deleterious expansions. 

The grain size distribution of spent foundry sand is very uniform, with approximately 85 to 95% of the material between 0.6mm and 0.15mm (No. 30 and No. 100) sieve sizes. Five to twelve percent of foundry sand can be expected to be smaller than 0.075 mm (No. 200 sieve). The particle shape is typically subangular to round. Spent foundry sand gradations are too fine to satisfy the fine aggregate standard specified in specification ASTM C33 Standard Specification for Concrete Aggregates. 

ASTM, Standard specification C33 concrete aggregate, in Annual Book of ASTM Standards, Vol. 04.02, American Society for Testing and Materials, West Conshohocken, PA, 1996. 

Odler, I. and Abdul-Maula, S. (1987). Cement and Concrete Aggregates, 9, 38M3. 

Dunstan, E. R. 1980. A possible method for identifying fly ashes that will improve the sulfate resistance of concrete. Cement, Concrete, Aggregates, 2, 22-30. 

Uses, Concrete aggregate, heal and sound insulation, filtration, finishing glass and plastics, road construction, scouring preparations, paint fillers, absorbents, support for catalysts, and dental abrasive. 

Tervahattu H, Kupiainen KJ, Raisanen M, Makela T, Hillamo R (2006) Generation of urban road dust from anti-skid and asphalt concrete aggregates. J Hazard Mater 132 39-46... 

Construction materials such as cement, concrete, aggregate, mineral and glass fiber insulation, and gypsum wallboard. 

Use Railroad ballast, highway construction, cement and concrete aggregate, raw material for Portland cement, mineral wool, and cinder block. 

Use Lightweight concrete aggregate, insulation, sound conditioning, fireproofing, plaster, soil conditioner, additive for fertilizers, seed bed for plants, refractory, lubricant, oil-well drilling mud. Filler in rubber, paint, plastics. Wallpaper printing, removal of strontium-90 from milk, absorption of oil spills on seawater, animal feed additive, packing, carrier for insecticides, catalyst and catalyst support, litter for hatcheries, adsorbent. 

A number of studies have been carried out to assess the feasibility of manufacturing constructional materials from rubbish to avoid landhll disposal. An example of these is the neutralysis process, which combines pulverized MSW with clay to form pellets, which are calcined to produce a light aggregate material. In addition, several reports are available on the use of the ash of incinerated MSW as a concrete aggregate. 

ASTM C586-92 Test method for potential alkali-reactivity of carbonate rocks for concrete aggregates (rock cylinder method) , 1992. 

T.P. Lees, Impurities in concreting aggregates , British Cement Association, 1987, ref 45.016. 

Finally, in order to obtain frost-resistant concrete, aggregates must also be able to withstand this type of attack. 

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