Research On The Application Of Waste Cathode Ray Tube Glass In Self-compacting Concrete

With the development of science and technology,more and more electronic products were eliminated,which produced a large number of abandoned CRT(Cathode Ray Tube)glass inevitably.Therefore,the recycling of CRT glass become urgent for environmental protection.Meanwhile,with the increase of domestic investment in infrastructure,the demand for sand and stone materials is also increasing.Domestic and foreign scholars have preliminarily proved the feasibility of using CRT glass to replace sand and stone materials in concrete,but few studies have focused on self-compacting concrete.Based on the waste CRT glass,the following parts of the research were conducted in this thesis.The main work and research results include:The waste CRT glass was treated by acid leaching technology.In the experiment,lactic acid,nitric acid,hydrochloric acid and acetic acid with different concentrations and liquid to solid ratios were used to leach lead from CRT glass with different particle sizes.The effects of leaching time and repeated leaching on leaching rate of lead were also considered.The concentration of lead in acid leachate was measured by icp-oes,and the leaching rate under the corresponding working conditions was obtained.The results showed that the leaching efficiency of lactic acid and nitric acid was better than other,and nitric acid was preferred chosen first.The leaching rate of lead reached a stable state after 24 hours of leaching.The extracts can be used for repeated leaching.The CRT glass was used to substitute the aggregate in the self-compacting concrete.The effects of CRT glass on working performance,physical performance and mechanical performance of self-compacting concrete were studied.Based on the problem of lead exudation,the lead exudation of self-compacting concrete was studied by changing the content of CRT glass,using CRT glass after acid treatment and adding biopolymer.It is found in the test that with the increase of the replacement rate of CRT glass,the slump-flow,the segregation percent,and the density increases,the water absorption decreases gradually,and the compressive strength of cube,splitting tensile strength,axial compressive strength and static elastic modulus decrease as well.However,the slump-flow of CRT glass was reduced after being treated with lactic acid.After the addition of biopolymers,the slump-flow was basically unchanged,the flow speed was slightly slower,and the segregation percent was reduced.After the pretreatment of lactic acid and the addition of biopolymer,the exudation of lead was obviously improved.The CRT glass was added into steel tube to prepare self-compacting steel tube concrete.The basic mechanical properties and long-term shrinkage deformation of CRT glass self-compacting steel tube concrete were studied.Through the axial compression test of self-compacting concrete on 18 CRT glass steel tubes,the relation curve of axial force N-strain ? of each specimen was obtained.The test results showed that the strength of concrete-filled steel tube did not decline after adding CRT glass.However,the ductility of concrete-filled steel tube became worse with the increase of replacement rate of CRT glass.