多重激发钢渣活性制备轻质墙材及其机制研究

Research on preparation of light wall materials by multiple activation of steel slag and its mechanism

钢渣作为钢铁工业的典型固废,长期以来难以得到大规模消纳利用。本文以钢渣、粉煤灰为主要原料,采用多重激发技术制备轻质墙材;研究原料配方、钢渣微粉的比表面积、激发剂种类及用量、养护制度等因素对样品抗压强度的影响;通过XRD、SEM分析研究胶凝体系的水化机制。结果表明:适当提高初期养护温度、增大钢渣微粉比表面积和加入激发剂均能提高样品的抗压强度。采用模数为1.2的水玻璃溶液作为碱性激发剂,在钢渣微粉、粉煤灰、熟料粉、石膏粉配比为70∶10∶15∶5,碱性激发剂和硫酸铝用量均为固体混合料的2%,钢渣微粉比表面积为516 m^(2)/kg条件下,50℃初期养护7 d后自然养护,样品的密度为821 kg/m^(3),28 d抗压强度可达3.98 MPa,主要指标满足《建筑用轻质隔墙保温条板》(GB/T 23450—2009)规范要求。在多重激发下作用下,产生大量的C-S-H和AFT会联结其它水化产物组成一个致密的整体,大幅度提高胶凝体系的强度。

As a typical solid waste in iron and steel industry,steel slag has been difficult to be consumed and utilized on a large scale for a long time.In this paper,steel slag and fly ash are used as main raw materials to prepare light wall materials by multiple excitation technology.The effects of raw material formula,specific surface area of steel slag powder,type and dosage of activator and curing system on the compressive strength of samples are studied.The hydration mechanism of cementitious system is studied by XRD and SEM.The results show that the compressive strength of the samples can be improved by appropriately increasing the initial curing temperature,increasing the specific surface area of steel slag powder and adding activator.The sodium silicate solution with a modulus of 1.2 is used as the alkaline activator,under the condition that the ratio of steel slag powder,fly ash,clinker powder and gypsum powder is 70∶10∶15∶5,the dosage of alkaline activator and aluminum sulfate is 2% of the solid mixture,the specific surface area of steel slag powder is 516 m^(2)/kg,after initial curing at 50 ℃ for 7 days,the sample density is 821 kg/m^(3).The compressive strength of 28 d can reach 3.98 MPa,and the main indicators meet the requirements of the specification of “Light Partition Wall Insulation Strips for Buildings”(GB/T 23450—2009).Under the action of multiple excitations,a large amount of C-S-H and AFT will be produced,which will join other hydration products to form a compact whole,greatly improving the strength of the cementitious system.