Influence of Steel Slag Activator on Mechanical Property and Durability of Offshore Concrete
To improve the offshore concrete durability and the steel slag powder utilization rate in concrete,the fluidity,setting time,mechanical properties,carbonation depth and chloride ion electric flux of steel slag concrete were tested.The influences of 3 kinds of activators(i.e.,sodium sulfate,desulfurization gypsum and desulfurization ash)on steel slag activity,chloride ion resistance and carbonation resistance of concrete were studied.The result indicates that the steel slag decreases the cement paste fluidity,and prolongs the setting time.As an activator,Na2SO4 can slightly shorten the setting time.The mineral powder and steel slag powder can reduce the time loss to a certain extent caused by concrete slump;but a certain amount of activator will weaken this effect.The desulfurization ash,Na2SO4 and desulfurization gypsum improve the flexural strength of concrete significantly,especially 3%Na2SO4 contributes more to the flexural strength.The effect of Na2SO4 and desulfurization gypsum composite activator on the flexural strength of concrete is greater than that of Na2SO4 and desulfurization ash composite activator and single activator.When each of the 3 activators is mixed alone,the 7 d compressive strength of concrete with steel slag-slag powder is slightly improved,and the improvement effect on the later compressive strength is not obvious.However,the composite activator has the significant effect on the compressive strength of concrete,especially 3%Na2SO4 and 4%desulfurization gypsum composite activator has the significant effect on mechanical properties.Na2SO4 increases the carbonation resistance and chloride ion penetration resistance of concrete by 23.9%and 43.7%respectively.The effect of Na2SO4 and desulfurization gypsum composite activator on durability is better than that of single activator.The desulfurization ash,desulfurization gypsum and Na2SO4 increase the steel slag activity,further improving the microstructure of concrete,and improving the mechanical properties and durability of concrete.
NETL
NSTL
万方数据
