水淬高钛高炉渣制备C40全固废混凝土试验研究

Experimental Study on Preparation of C40 Concrete with Industrial SolidWastes from High-titanium Blast Furnace Slag

为了提高低活性水淬高钛高炉渣的综合利用率,采用多固废协同激发的技术路线制备胶凝材料,通过正交试验确定了水淬高钛高炉渣-钢渣-石膏基胶凝材料的优化配比,并以原状水淬高钛高炉渣颗粒为骨料制备全固废混凝土。研究结果表明,胶凝材料的优化配方为:水淬高钛高炉渣和钢渣质量比为2∶1、脱硫石膏掺量为16%、减水剂掺量为0.28%、水胶比为0.24。当胶砂比为1∶1时,在标准养护条件下,全固废混凝土试块28 d抗压强度可以达到40 MPa以上,符合C40混凝土强度要求。XRD、TG-DTA和SEM-EDS分析表明,在脱硫石膏的激发下,水淬高钛高炉渣与钢渣相互促进,协同水化,水化产物以针棒状的钙矾石(AFt)和无定形的C-S-H凝胶为主。随水化龄期延长,水化产物不断增多,钙矾石晶型趋于稳定,网状C-S-H凝胶与钙矾石穿插形成的致密结构有利于混凝土强度的增长。

In order to enhance the rate of comprehensive utilization of low activity water-quenched high-titanium blast furnace slag,the cementitious materials were prepared by the technical route of multi-solid waste synergistic excitation.The optimized ratio of water-quenched high-titanium blast furnace slag-steel slag-gypsum-based cementitious materials was determined by orthogonal test.All solid waste concretes were prepared by using undisturbed water-quenched high-titanium furnace slag as aggregate.The results show that the optimal ratio of cementing materials is:the mass ratio of high-titanium blast furnace slag and steel slag is 2∶1,desulfurization gypsum content is 16%,superplasticizer content is 0.28%,water cement ratio is 0.24.When the rubber sand ratio is 1∶1,the 28 d compressive strength of all solid waste concrete test blocks can reach more than 40 MPa under standard curing conditions,meeting the requirements of C40 concrete strength.The results of XRD,TG-DTA and SEM-EDS show that high-titanium blast furnace slag and steel slag promote each other and coordinate hydration under the stimulation of desulphurization gypsum.The hydration products are mainly needle-stick ettringite(AFt)and amorphous C-S-H gel.With the increase of hydration products,ettringite crystal tends to be stable,and the dense structure formed by the interpenetration of C-S-H gel and ettringite is conducive to the growth of concrete strength.