Concrete Standard/Grades

	I'm looking for standard concrete mixture for radiation shielding purposes. Will u please guide/give me some information regarding; a) Concrete standard. b) Its' composition/mixture ratio. c) Aggregate size. d) Density.
	Radiation shielding concrete is heavy weight concrete made with aggregates and additives that help absorb radiation and can resist its destructive effect better than regular aggregates. There are 2 sources I would recommend for some basic information. Both are from the ACI (American Concrete Institute) Manual of Concrete Practice. The first is from Standard Practice 211 (appendix 4) which provides guidelines for a step-by-step design of heavy concrete. The second is Chapter 11 of Standard Practice 304R that provides general information about aggregate selections and properties of additives. Table 11.2.2 will provide you with a list of typical aggregates and their properties. Table 11.3.2 includes typical proportions for nuclear shielding concrete of different sources and different functions. These proportions and aggregates should be used in the design procedures of practice 211. The manual should be available in any university engineering library that has a Civil Engineering program. You can also get it directly from ACI by following the links on my web site. Where are you and why do u need that information?
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