Analysis of the influence of different active magnesium oxide expansion agents on the deformation characteristics of concrete
Concrete materials often need to withstand the impact of temperature changes,such as sun and rain and other conditions,concrete will shrink or expand,seriously affecting its stability.In order to improve the mechanical properties of concrete materials,the influence of different activity of magnesium oxide expander on the deformation characteristics of concrete was analyzed under the condition of varying temperature.The chemical composition of the main raw materials was determined,and the activity values of the used magnesium oxide expansion agent were determined by citric acid method to be 70 s,140 s and 210 s,respectively,and the concrete samples were prepared by these magnesium oxides.The compressive strength of different dosage and active magnesia concrete was tested,the expansion rate of concrete prepared with different active magnesia was calculated under varying temperature,and the shrinkage rate of each test sample under drying condition was tested.The experimental results show that the mechanical properties of concrete are better when the dosage of MgO expansion agent is 5.5％under different activities,and the expansion rate of 210 s active expansion agent concrete is higher and it is not easy to deformation at varying temperature,while the expansion rate of 70 s and 140 s active concrete is relatively low,and the concrete is easy to deformation.The shrinkage rate of 210 s active expansion agent concrete is smaller than that of the other two active expansion agent concrete,and it is not easy to shrink and deform.
variable temperature conditiondifferent activitymagnesium oxideexpansion agentconcretedeformation characteristic
万方数据
维普
