Study On The Influence Of Mineral Admixture On Concrete Workability,Mechanical Properties And Water Permeability

With the development of society and the increasingly diverse needs of modern construction projects,the research and innovation of high-performance concrete has become increasingly important.Previous studies have shown that the addition of active mineral admixtures and high performance water reducers can effectively enhance the performance of concrete;at this stage,the traditional commonly used active mineral admixtures are slag,silica fume,etc.,but their sources are scarce.The price is too high and does not have environmental significance,and can not meet the growing needs of concrete engineering.Exploring the new mineral admixtures instead of traditional admixtures,improving the relevant performance of concrete in various practical engineering applications,to meet the urgent needs of the sustainable development of high-performance concrete should be put on the agenda.In this paper,in view of the problem of waste pollution on ceramic production line and the performance and economical requirements of mineral admixture in actual engineering,industrial waste slag polished brick powder,economical zeolite powder and highly active metakaolin are selected;The basic properties of concrete with different amount of polished brick powder,zeolite powder and metakaolin were determined.The influence of three mineral admixtures on concrete workability,mechanical properties and water permeability coefficient was studied.The filling density was introduced innovatively.And the measurement and calculation of the average liquid layer value,based on the average liquid layer value to explore the influence and correlation of three mineral admixtures on the fluidity of concrete,and then analyze its relationship with the performance of concrete,more targeted The reference for the possibility that the three mineral admixtures are actually applied to the project and related performance improvement methods.The results of this study show that:(1)Polished brick powder,zeolite powder and metakaolin can reduce concrete slump and expansion,improve cohesiveness and optimize concrete performance.(2)Polished brick powder,zeolite powder and metakaolin can optimize the internal pore structure of concrete.With the decrease of porosity,the impermeability of concrete is improved.The incorporation of polished brick powder improves the resistivity of concrete 28 d.Due to the slower potential activity of zeolite powder,the electrical resistivity of concrete 28 d decreased slightly,and the amount of metakaolin had no obvious effect on concrete resistivity.(3)After the blending of polished brick powder,the compressive strength of concrete 28 d and 70 d is improved;the effect of zeolite powder on concrete compressive strength is obvious at the later stage,and its 70 d compressive strength is obviously optimized and enhanced compared with 28d;comprehensive analysis The volcanic ash effect of different metakaolin content and the influence on the compressive strength of concrete,the optimum is obtained when the dosage is 10%.(4)The variation coefficient of concrete seepage coefficient with the three mineral admixtures is basically the same.The water seepage process of the test block is mainly concentrated in the first 1.5 hours,and the water permeability coefficient decreases with the increase of the content of the three admixtures.(5)The influence of three mineral admixtures on the properties of concrete can be analyzed based on the packing density and the average liquid layer value.The fluidity,cohesiveness and porosity of the three admixtures are obtained.The influence of the rate is closely related to the average liquid layer value.The average liquid layer value is the fundamental controlling factor of the concrete fluidity.It is also the compressive strength and water seepage of the concrete due to the change of the average pore layer value.The coefficient also has a certain influence.By measuring and analyzing the average liquid layer value,it provides reference and application value for more practical engineering on the functional requirements of concrete test blocks.