Research On Shrinkage And Construction Performance Of Alkali Slag Cementing Material

Alkali activated slag cementing materials is a kind of environmentally friendly building materials with good physical and mechanical properties,durability.It excited the potential activity of slag by the alkaline materials.NaOH and liquid water glass had the best effect on alkali activated slag cementing materials,liquid water glass is more better between them with the development.Because the state of water glass is liquid and it should mixed with NaOH when it was used,these were inconvenient and had potentially dangerous while it was operating.Solid sodium silicate has the same main composition with liquid water glass,it can grind and mixed with the slag,finally being a product.When the product need to be used,it is convenient to just add water to mixing,easy to use.In the research,basic properties,contraction performance aspect of alkali activated slag cementing materials,cement were used to modify the excited result of solid sodium silicateThe results showed that some certain differences existed the excited result between two kinds of exciting.In comparison to solid sodium silicate,when exciting is liquid water glass,the alkali activated slag cementing materials and cement strength are higher.But in fact,alkali activated slag cementing materials also has the high strength,and it has advantages like low viscosity,slowly hydration rate.The most is it's convenient to use.Barium nitrate and borax-sucrose has good used to delay setting time.Barium nitrate can effective delay setting time with small admixture and has less influence on strength.boraxsucrose has the best effect in delaying setting time,it's initial setting time can reach 4h,but borax-sucrose can lead the 46%reduction to 28 d strength.Naphthalene series high range water reducing agent can increase the fluidity in a way.It has highly linear correlation with the adsorption quantity of alkali slag,it changes with the change of the adsorption quantity.The admixture of naphthalene series is big and it cause strength drop of alkali activated slag cement.The incorporation of mineral admixtures have a certain influence on alkali activated slag cement mortar,concrete construction performance.While the admixture of fly ash and metakaolin is 8%,fluidity of alkali slag cement mortar is higher than 32% admixture,magnesium oxide and metakaolin can improve the strength.Fly ash can improve the alkali slag concrete's slump,mineral admixtures has little effect on fall alkali slag concrete strength.chemical shrinkage of the alkali slag cement materials is smaller,when the excitation agent is liquid sodium silicate,similar with Portland cement;while excitation agent is liquid sodium silicate,alkali slag drying shrinkage of concrete is smaller too;Naphthalene series water reducing agent increases the contraction of alkali slag cement materials;Metakaolin is best to restrain alkali slag cementing materials chemical shrinkage,it's shrinkage drop 27.9% at 28d;Magnesium oxide has good effect on the reduction of alkali slag cement mortar,it's shrinkage drop39% at 60 d,but because of slow reponse,the effect not good at initial;Fly ash increases alkali slag drying shrinkage of concrete,UEA restrain alkali slag concrete shrinkage effective,when dosage is 15%,120 d shrinkage is reduced by 28%.