利用盾构渣土制备水泥混合材的可行性研究

Feasibility Study on Preparation of Cement Mixture by Shield Muck

地铁盾构渣土是城市轨道交通建设过程中大量产生的泥态废弃物。由于盾构渣土来源的广泛性、区域性、成分的复杂性,以及施工工艺的原因,使得盾构渣土回收利用困难,阻碍施工进度,污染城市环境。为进一步促进盾构渣土资源化再利用,本文主要对我国盾构渣土资源化再利用途径的现状进行了分析;以郑州市地铁四号线、十四号线的渣土为例,测定了渣土的含水率及颗粒级配,并进行了XRD分析和差热分析,研究其矿物成分和物理特性随温度变化的情况。通过渣土水泥试块抗压强度与水泥净浆试块抗压强度的比值来反映渣土活性的变化,探讨了温度以及CaO、CaSO_4·2H_2O两种激发剂掺量对渣土活性的影响。研究表明:随着温度的升高,渣土水泥试块的抗压强度先减小后增大,在800℃时达到水泥净浆试块抗压强度的85. 7%,满足Ⅱ级粉煤灰的抗压强度比要求。

Metro shield muck was a lot of mud waste generated during the construction of urban rail transit. Because of the extensiveness of the source of the muck of the subway, the complexity of the region, the complexity of the components, and the reasons for the construction process, the recycling of the muck in the subway is difficult, which hinders the construction progress and pollutes the urban environment. In order to further promote the reutilization of subway slag, the status quo of the way of reutilization of subway slag in China was mainly analyzed, and takes the slag of subway lines No.4 and No.14 of Zhengzhou as examples to determine the slag. The moisture content and particle size distribution of the material were analyzed by XRD and differential thermal analysis. The changes of the mineral composition and physical properties with temperature were studied. The change of the activity of the muck is reflected by the ratio of the compressive strength of the muck cement block and the compressive strength of the cement pulverized soil test block. The influence of temperature and the amount of CaO and CaSO 4·2H 2O admixtures on the activity of the muck soil is discussed. The research shows that with the increase of temperature, the compressive strength of the slag cement test block first decreases and then increases, reaching 85.7% of the compressive strength of the cement paste test block at 800 ℃, meeting the grade Ⅱ fly ash.