Study On The Effect Of Double Mixing Waste Glass Powder And Mineral Admixture On Concrete Performance

In recent years,large-scale infrastructure construction and rapid industrial development have resulted in the accumulation of a large number of industrial by-products,occupying land and polluting the environment.The national carbon neutral development goal will promote the greening and industrialization of buildings,and the resource utilization of construction waste should be enhanced.Glass,as a widely used building material in daily life,has a huge amount of scrap every year.After being ground,it has the characteristics of volcanic ash.When mixed into concrete,it can reduce the amount of cement and improve the durability and long-term mechanical properties of concrete.However,due to the low activity of waste glass powder in the early stage,its single mixing in concrete replaces part of cement,resulting in poor mechanical properties of concrete in the early stage,which is not conducive to practical engineering application.In this paper,glass powder,slag powder and fly ash are mixed into concrete,and the change rules of mechanical properties and durability properties of concrete mixed with glass powder are revealed by controlling the incorporation ratio and the type and amount of added mineral admixture.The following studies are mainly carried out:(1)The compressive and tensile properties of the admixture concrete were studied.The results showed that the mechanical properties of the single glass powder concrete were low before 56 d,and decreased with the increase of the glass powder content,but could reach or approach the level of the reference group after 180 d.With the same total substitution rate,the strength of double mixed concrete is stronger than that of single mixed concrete,and the rapid strength growth period of glass powder concrete can be advanced to 14 days by adding mineral admixture,reaching 83.7-94.5% of the benchmark group.The mechanical properties of concrete are better when the content of glass powder and mineral admixture is 15%,and the properties of concrete when mineral admixture is slag powder are better than fly ash.(2)The chloride ion resistance of admixture concrete is studied.The results show that the chloride ion resistance of concrete is significantly improved by glass powder;The chloride ion resistance of single glass powder concrete decreases first and then increases with the increase of the dosage,and the dosage of 30% is the best.The chloride ion resistance of double-mixed concrete is slightly lower than that of single glass powder concrete(7.7%-14.6%),but at least 50.3% better than that of ordinary concrete.When the temperature change of specimen is small,the initial current has a good linear relationship with the value of electric flux and chloride ion diffusion coefficient.In this paper,the chloride ion resistance of mixed concrete can be evaluated by the initial current.(3)The frost resistance of admixture concrete is studied.When the age is 60 days,due to incomplete hydration of concrete,the frost resistance will be adversely affected when 30%glass powder is added;Double mixing can obviously improve the frost resistance of concrete,and the best mixing ratio is 1:1 when the total mixing amount is 30%.(4)the study of admixture concrete chloride ion penetration model,the chloride ion diffusion coefficient of time-varying model is established,and the freeze-thaw cycle correction coefficient,analyzes the waste glass powder dosage,erosion time,penetration depth and freeze-thaw cycles on chloride ion concentration distribution,the simulation results with the test conclusion,the erosion of time increases the chloride ion concentration and penetration depth.Waste glass powder is beneficial to the chloride ion erosion resistance of concrete,and the freeze-thaw cycle will reduce the chloride ion erosion resistance of concrete,and with the increase of freeze-thaw times,the reduction effect becomes more obvious.