纳米SiO_(2)对氧化镁激发矿渣材料性能的影响试验研究

Experimental Study on Influence of Nano-SiO_(2) on Properties of MgO-Activated Slag Material

为改善MgO-激发矿渣材料(MASM)力学性能,利用纳米SiO_(2)(NS)促进MASM的强度发展,研究了不同NS掺量对MASM凝结时间、抗压强度、水化历程、水化产物和微观形貌的影响,分析并揭示了NS的作用机理。研究结果表明:随着NS掺量的增大,MASM凝结时间逐渐缩短,流动度逐渐减小;NS掺量越大,矿渣水化越快,主要水化峰出现越早,峰值越高。NS不仅促进了MgO的反应和C-(A)-S-H的形成,还提高了MASM的结构密实性。掺入1%~2%(质量分数)的NS,可将MASM的抗压强度分别提高7.12%~33.37%(3 d)、12.44%~26.29%(7 d)、12.49%~31.09%(28 d)。

In order to improve the mechanical properties of MgO-activated slag material(MASM),nano-SiO_(2)(NS)was used to promote the strength development of MASM.The effects of NS dosage on the setting time,compressive strength,hydration process,hydration products and microstructure of MASM were investigated and the mechanism of action of NS was revealed.Experimental results show that the addition of NS changes the performance of MASM obviously.A higher dosage of NS results in a shorter setting time and a lower flowability of MASM.The larger the NS content is,the faster the slag hydration is,the earlier the main hydration peak appears,and the higher the peak value is.The addition of NS not only promotes the reaction degree of MgO and the production of C-(A)-S-H gel products,but also contributes to more densified microstructure of MASM.The compressive strengths of MASM increases by 7.12%~33.37%(3 d),12.44%~26.29%(7 d)and 12.49%~31.09%(28 d)by adding 1%~2%(mass fraction)NS.