Preparation And Mechanical Properties Of High Volume Iron Tailings Sand Concrete

With the rapid development of society,energy and environmental issues have been upgraded to problems that cannot be ignored.Although China is rich in resources,however,the development of various existing favorable resources is insufficient.Paying attention to and rationally utilizing resources will effectively alleviate this problem.Iron tailings is one of the largest industrial solid wastes in China.At present,the utilization rate of iron tailings is still very low,and the large stockpiling of tailings will also bring environmental pollution.If iron tailings sand is used instead of natural river sand to prepare concrete,it can not only reduce the demand for ordinary concrete in infrastructure construction,reduce the cost of mining natural river sand,but also improve the utilization rate of iron tailings.Through experimental research and theoretical analysis,this paper mainly studies the mix design and mechanical properties of iron tailings sand concrete.The main work and results of the whole research process are as follows:Firstly,the concrete specimens were prepared by replacing some concrete fine aggregates with iron tailings sand.By incorporating fly ash and adjusting the sand rate of concrete,the adverse effects of concrete due to the incorporation of iron tailings sand were reduced,and the different mixing ratios were compared.Under the uniaxial compressive strength of iron tailings sand concrete,the optimal mix ratio of high cost-effective tailings sand concrete with the highest cost performance and green environmental protection was selected.Secondly,the deformation properties of iron tailings sand concrete with different substitution rates are studied.The elastic modulus,stress-strain curve and fracture energy of iron tailings sand concrete under different mixing ratios are compared to analyze different iron tailings sand blending.The influence of the amount and sand ratio on the properties of iron tailings sand concrete,it is found that with the increase of iron tailings sand content,the concrete stiffness decreases,the ability to resist elastic deformation is weakened,the brittleness is enhanced,and the concrete damage is more rapid.Finally,considering the application in actual engineering,the reinforced concrete beam is prepared by using iron tailings sand and the bending test is carried out.The calculation formula of the ultimate bending moment design value of the iron tailings reinforced concretebeam is corrected,from environmental protection and secondary utilization of tailings sand and from the perspective of safety performance,the feasibility of applying iron tailings sand concrete to practical engineering is analyzed.The results show that under the optimal mix ratio,the compressive strength of iron tailings sand concrete can reach 95% of ordinary concrete,the elastic modulus can reach 74% of ordinary concrete,and the bending capacity of iron tailings reinforced concrete beam can reach 78.5% of ordinary concrete beams can be applied to actual projects under certain conditions.