Research On Crack Control Of Mass Radiation Protection Concrete In Medical Buildings

A large number of harmful cracks will reduce the overall performance and stiffness of concrete.The phenomenon of concrete fall and steel corrosion will seriously affect the durability of the structure.Large volume of radiation resistant concrete is accompanied by cracks generated by thermal stress during curing.These cracks have negative effects on medical buildings and other components require special protection.In order to reduce the probability of temperature cracks,improve the protection effect of radiation protection and ensure the safety of surrounding environment,crack control is urgent.For mass concrete,a large amount of hydration heat generates during pouring can cause temperature difference between inside and outside,resulting in temperature stress and forming cracks.To avoid excessive cracks reducing the bearing capacity and cause of radiation leakage,based on the analysis of the mechanism of cracks,the control measures are put forward according to the total construction process before construction,such as aggregate selection,construction process,mixing,pouring and monitoring,as well as the overall structure maintenance in the later stage of construction.Then,from the maximum control of radiation exposure,time,distance and physical isolation protection methods are adopted to reduce the cumulative value of radiation in vivo and the goal of radiation protection is achieved.Take a hospital accelerator room in Tangshan as an example.By using low heat cement as cementing material when pouring,the apparent density of large limonite,barite and other coarse aggregate skeleton as to improve radiation blocking ability,filling the gap to enhance compactness,we can reduce the probability of crack caused by temperature can be reduced.Through monitoring the temperature change during mixing,pouring and curing,the temperature,such as low temperature storage,condensation water,air cooling,sprinkling and water conservation,are used to reduce temperature and control the occurrence of cracks effectively.On forming patrol detector radiation on storage radiation therapy instrument room detection are compared by using the radiation of concrete components,the indoor radiation value in a certain range of standard,the scope of radiation outside tends to zero,which indicates that the addition of barite in large volume concrete in radiation protection materials,plays a significant protective effect.