| 摘要 |
#CMT# #/CMT# Radiation-screening constructional concrete (I) comprises (a) a binder and (b) at least one electricity conducting, electricity diverting or radiation repelling material. #CMT# : #/CMT# Independent claims are included for: (1) constructional articles or construction elements produced from (I); and (2) a method for preparing a construction article or element, involving (i) producing a form; (ii) placing reinforcement in the form; and (iii) filling the form with (I). #CMT#USE : #/CMT# The use of (I) is claimed in the production of construction articles or elements. (I) shows radiation screening effects, and buildings, rooms etc. formed from (I) protect inhabitants against harmful effects (e.g. sleeping disorders) caused by environmental electromagnetic fields ('electrosmog') of artificial or natural origin (e.g. due to transmission plants, power lines, image screens or geological radiation). Screening with (I) is also useful within buildings to minimize emission of radiation into the environment from an internal radiation source, e.g. a medicinal appliance in a hospital. #CMT#ADVANTAGE : #/CMT# Inclusion of the screening component (b) in concrete provides a good radiation-protective effect without adversely affecting the other properties of the concrete, e.g. as regards production, storage, transport and cost. The need for subsequent application of protective layers or films to concrete structures is also eliminated. #CMT#CERAMICS AND GLASS : #/CMT# Preferred Composition: (b) is a carbon-based material, specifically graphite, especially colloidal, flock, amorphous or synthetic graphite. (I) optionally also contains a silicon-based electricity conducting, electricity diverting or radiation repelling material, specifically quartz. The binder (a) is white cement, calcium aluminate cement, gray cement or mortar cement. (I) optionally also contains a filler (especially gravel), a pozzuolana additive and/or other additive(s) selected from fluidizers, retardants, flow agents, sealing agents, hardening or solidification accelerators, air pore agents and/or frost protectants. (I) is especially produced from a mixture of 10-20% binder, 30-60% gravel, 30-60% quartz sand, 0.25-2.0% graphite, 0.01-5% fluidizer, 0.01-4% retardant, 0.5-5.0% hydrolite, 0.01-1.0% anticavitation agent and 2-7.5% additional water. #CMT#EXAMPLE : #/CMT# Portions of a constructional concrete, produced by blending a mixture of 1180 kg gravel 4-16, 545 kg quartz sand 0.01-0.2, 220 kg quartz sand 0.2-0.4, 325 kg cement, 2 kg Sika PerFin-300(RTM: anticavitation agent), 50 kg hydrolite, 4.5 kg fluidizer and 108 kg additional water, were mixed with various amounts of graphite. In radiation screening tests, the amounts of radiation passing through a 20 cm wall of the concrete were reduced 212, 350, 1016 and 3706-fold for graphite contents of 0%, 0.25%, 0.5% and 1.0% respectively. The corresponding strength values of the concretes (28 days) were 53.8, 42.4, 41.35 and 35.7 N/mm 2>. |
