Shrinkage And Creep Properties Of Alkali Slag Concrete

Alkali excitation of concrete as a new green building materials,has a good environment and economy coordination,but due to the large deformation of concrete and cannot get a wide range of application.Alkali slag concrete as a kind of alkali excitation types,in the production of alkali slag cement excitation energy consumption is only 30%of ordinary Portland cement,CO₂ emissions only 1/10¹/15 of Portland cement,and it has many excellent performance,high strength,low porosity,good durability,less water,low hydration heat and good protection of reinforcement,the characteristics of the above makes the prospect of the alkali slag concrete is very light.Thus figured out how to control the alkali slag concrete shrinkage and creep deformation is needed to overcome difficulties.In this paper,on the basis of other scholars research on alkali slag concrete shrinkage and creep experiment research,explore mixed with the change of the content and water/cement ratio,alkali slag concrete shrinkage and creep change rule.Through concrete mechanics performance test and long-term creep loading test,long-term shrinkage test obtained experimental data,by adopting the combination of experiment and numerical simulation method to seek out suitable for alkali slag concrete creep and shrinkage prediction model.The results found in alkali slag concrete system,silica fume with ball effect,ash,utility,can increase strength after incorporation,inhibiting alkali slag concrete shrinkage,concrete strength when the dosage of 5%maximum,10%reduction effect is best;The incorporation of fly ash reduces the strength and creep of concrete,but also increases the shrinkage.The increase of water cement ratio will lead to concrete porosity increased,gelled material between mutual bond yield decline,at the same time with microscopic cracks,these three factors can reduce the strength of the concrete in different extent.The change of water glue ratio has the greatest influence on the strength and creep of concrete.The strength of 28d is 75.47MPa at 0.44,while the strength decreases by11.99%and 31.01%when the water glue ratio increases to 0.47 and 0.50.The water gels were 0.47 and 0.44 respectively,and the creep coefficient difference was 0.1873 at 28d.The difference between them reached the maximum value of 0.5063 at 180d.Apply now more CEB-FIP?1990?,ACI,B3,GL2000 prediction model with the experiment measured the creep curve fitting,CEB-FIP?1990?model fitting effect is best in the above model,the experiment of three groups of concrete other conditions are consistent,different to the strength of concrete,so combining with the numerical fitting,to modify the strength of the concrete,to form a new alkali slag concrete creep prediction model.Small contraction curve in the model,the main cause of this is the name of the small shrinkage coefficient,by combining the excellent part of model combination,combined with new alkali slag concrete shrinkage prediction model.