Study On Alkali Slag Concrete Mechanics Performance

Make full use of metallurgical industry by-product granulated blast furnace slag production of alkali activated high performance cement,has become one of the hot research direction in the field of building materials,which is one of great significance for building a resource-saving and environment-friendly society.In recent years,a great deal of research has been done on the utilization of slag,and some achievements have been made.At present,slag is mainly used as filling material or part of Portland cement clinker to produce slag cement,or as the main raw material of alkali activated cement.In this paper,the compressive strength,static stress-strain properties and dynamic stress-strain properties of alkali activated slag concrete have been studied.At the same time,the flowability of concrete has been studied.The influence of alkali content,fly ash content,lime content and silica fume content on the fluidity and cubic compressive strength of alkali activated slag concrete was analyzed.The results show that fly ash can improve the workability,volume 25% is better,strength will not be significantly decreased;The higher the amount of water glass,the better the fluidity and the higher the strength;Metakaolin can significantly reduce strength and fluidity.When the dosage is 30%,the concrete has little strength;Silica fume can cause fluidity and early strength decrease,but it can promote the later strength;lime can improve the early strength,but will cause a decrease in late strength,and has a certain negative impact on liquidity.The influence of fly ash content,water cement ratio and alkali content on the static stress-strain properties and dynamic stress-strain properties of alkali activated slag concrete was studied.The static stress-strain test results show that the alkali slag concrete stress-strain curve and ordinary concrete are similar,but the ascent has discreteness,decreased significantly steeper;increase the peak strain of concrete with fly ash proportion and water cement ratio decreases,with increasing alkali content increased;the ratio of compressive strength of alkali activated slag concrete compressive strength and prism is about 1.09.The dynamic stress-strain test results show that the incorporation of 50% fly ash or water glass content of 16% could significantly increase the strain rate sensitivity of concrete;dynamic compressive strength increases with the increase of strain rate increases linearly with the increase of strain rate;the peak strain and showed an increasing trend.