Study On The Influence Of Dolomite Powder On The Basic Performance Of Concrete And Its Resistance To Chloride Ion Attack

Dolomite Powder is a powder of stone chips produced by the crushing of dolomite.It has a wide range of applications in construction,medical,chemical,and agricultural fields.Dolomite powder is an economical and practical mineral admixture.It can not only reduce the amount of cement and reduce the cost of concrete production,but also compensate for the shrinkage of concrete and improve the porosity of the concrete.It can solve the problem of environmental pollution by waste stone chips by turning dolomite powder into resources..This article is funded by the National Natural Science Foundation of China(51778272),combined with the existing theoretical knowledge and previous research content,using dolomite powder as the research object,exploring its role in reducing the amount of cement and fly ash and improving the performance of concrete,and researching dolomite powder The improvement of the bending performance of concrete beams further enhances the engineering value of dolomite powder.In connection with the actual project,it puts forward suggestions for the application of dolomite powder in concrete engineering,and also provides data and theoretical support for the practical engineering application of dolomite powder in the future.The main contents are as follows:(1)Research on the basic performance of concrete mixed with dolomite powder.Starting from the compressive strength,elastic modulus and drying shrinkage of concrete,the basic properties of concrete mixed with dolomite powder are studied.The results show that the early strength of concrete mixed with dolomite powder causes a decrease in the early strength of concrete,and then gradually approaches with age,and the later strength declines to a small extent.When the mass of dolomite powder replaces less than 5% of cement,the elastic modulus of concrete will be improved.When the content of dolomite powder exceeds 5% and the content of fly ash is reduced,the elastic modulus of concrete mixed with dolomite powder will decrease;It has a good effect on compensating for the shrinkage of concrete,and the shrinkage of concrete decreases with the increase of dolomite powder.(2)Research on the flexural performance of concrete beams mixed with dolomite powder.Through the concrete beam bending test,the deflection,ultimate bearing capacity and cracks of concrete beams are deeply discussed,and the performance of concrete beams mixed with dolomite powder is studied.The test results show that the addition of dolomite powder enhances the ultimate bearing capacity of concrete beams and improves the concrete at the same time.The deformability of the beam has no obvious improvement effect on the occurrence and development of the largest crack in the concrete beam.(3)Research on the diffusion of chloride ions in dolomite powder concrete based on COMSOL.The final results show that the addition of dolomite powder in concrete can significantly reduce the chloride ion diffusion coefficient and chloride ion concentration,and is positively correlated with the dolomite powder content;use COMSOL software to establish the chloride ion diffusion model in concrete and test the chloride ion in concrete Concentrations are compared to verify the feasibility of the long-term prediction of chloride ion diffusion in concrete mixed with dolomite powder,and to predict the chloride ion concentration in concrete at 1800 d.(4)Dolomite powder admixture ratio is recommended.According to the engineering characteristics of dolomite powder used as a mineral admixture,it is combined with actual engineering,and based on the existing test conclusions,suggestions for the use of related dolomite powder are proposed,which provide references for subsequent dolomite powder research and engineering applications.This paper analyzes the compressive strength,elastic modulus and drying shrinkage properties of dolomite powder concrete,and then studies the flexural performance of dolomite powder concrete beams.At the same time,it studies the resistance of dolomite powder to the corrosion of chloride ions,which provides technical support for the engineering application of dolomite powder.