| In addition to some general functions, more importantly, the shielding concrete also plays an important role in shielding y rays and neutron rays. The application of the shielding concrete shall be expanded gradually as the development of nuclear reactor technology and the implementation of national long-term nuclear power policy. Whereas the current research made on such respects of its performance is not quite systematical and comprehensive, such methods as theoretical analysis, testing in laboratory and simulating with computers have been adopted to make a further study on domestic raw materials and its performance, as well as mix design ratio, performance, construction techniques and parameter of serial shielding concrete with the density of 2320 kg/m3-5700 kg/m3, which has been made valuable achievements on its design, construction and inspection in China.1 .After testing and analyzing different ore materials on the respects of unit volume density, index of crushed materials and crystal water, it shows that these ore materials (namely hematite, magnetite, barite, cast iron &steel shot, limonite, serpentine, boric dahllite made in Jiangsu,Liaoning,Jilin,Shandong,Henan,Guangxi and Sichuan etc.) can be used as coarse/fine aggregates for shielding y rays and neutron rays. If shielding y rays and neutron rays at one time, two or three ore mixed aggregates and admixture shall be applied.2.When the design proportion is made, coarse aggregates with constant grading and fine aggregates with the density of close to coarse one should be applied. The minimum difference shall be the best. Besides limonite and paigeite applied to the concrete for shielding neutron rays, both cement and admixture with boron shall be applied so as to intake hydration water and increase the amount of boron. For the concrete with high density, a certain amount of admixture (fly ash cement, limonite, chromite etc.) shall be added.3. The mix design ratio for such shielding concrete adopted with both quality mix proportion and volume mix proportion has been made. By this method, the mix proportion of shielding concrete with the density of 2320 kg/m3, 3000 kg/m3, 3300 kg/m3, 3600 kg/m3, 3900 kg/m3, 4600 kg/m3, 5700 kg/m3 has been designed, which can be directly used in the construction.4. According to the results of testing the concrete with the density of 3600 kg/m3 for shieldingγrays and neutron rays , the way of the mix design ratio for the shielding concrete has been created with adopting ANFIS. The fitting precision and forecast precision shall reach 90% and 89% above respectively, which creates a new way for scientific design of this concrete mix ratio.5. The density of the shielding concrete has a lineal relation with the density of aggregate. When stabilizing the amount of cement, water reducing agent and grit proportion, the density shall increase with adding up the amount of iron ore, water quantities shall decrease on the contrary. Water quantities and grit proportion have the primary impact on the slump that shall increase with water quantities, water cement ratio and grit proportion, the slump will increase by 5-20mm with adding water of 5-10kg, so 5-20mm with 2% increase. The compressive strength is mainly influenced by water cement ratio, which shall decrease with the increase of water cement ratio. The relation among compressive strength, flexural strength and splitting strength shall be shown just as follows: fcc=6.90ff, fcc=9.72fts. The factors for shieldingγrays which influence the density, slump and compressive strength of the concrete, are the same as that for shielding neutron rays.6. Different construction technique and technical parameter shall be applied to each shielding concrete. For the shielding concrete with the density of less than 3600kg/m3, placing with pump is 6-10 times quicker than that with conventional methods. As for those with the density of 3600kg/m3 above, the conventional method shall be adopted.7. It creates the non-radial method to test the uniformity of shielding concrete and it also presents the criterion (0.98pc,d≤Ïn≤1.04Ïc,d and 0.99Ïc,d≤Ïcu≤1.03Ïc,d) to evaluate its uniformity.8. It creates the radial method to test the uniformity of shielding concrete, Density of each measurement point can be calculated in shilding concrete according to the attenuation value of the dose equivalent of radiant point due to before and passing shilding concrete, The density of calculation results shall be used for identifying its uniformity according the above-mentioned criterion.
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