Concrete is one of the most fire‐resistant materials, whose resistance depends on the chemical and structural characteristics of the hydrated calcium silicate (C‐S‐H) formed in the hydration and hardening process. However, the structure and composition of this C‐S‐H varies with the time of hydration. The effect of the composition of the calcium silicate on the anhydrous material formed has been studied after subjecting it to an accelerated study of the effect of fire, irradiating it with a CO₂ laser. Changes in the composition of C‐S‐H can lead to changes in the mechanical properties of the cement. C‐S‐H samples with different chemical composition (Ca/Si ratios 1 and 2) as well as different synthesis processes (double decomposition and hydrothermal) were studied. The crystalline phases obtained after heating were identified through micro‐Raman spectroscopy, which confirmed the formation of anhydrous calcium silicates with the same Ca/Si ratio as the initial one. In C‐S‐H gels with a Ca/Si ratio of over 1.5, stable Ca (OH)₂ was formed. Scanning electron microscopy/energy dispersive X‐ray analysis analysis determined that in the process of heating with the laser, water is lost fast, generating porous structures. Such porosity is higher in materials with a lower Ca/Si ratio.

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关于火灾期间温度升高导致C–S–H脱水的研究

混凝土是最耐火的材料之一，其耐性取决于在水化和硬化过程中形成的水​​合硅酸钙（CS）的化学和结构特征。但是，这种C–H的结构和组成随水合时间而变化。对硅酸钙的组成对形成的无水材料的影响进行了研究，然后对其进行了火势的加速研究，并用CO ₂对其进行了辐照。激光。C‐H‐H成分的变化会导致水泥的机械​​性能发生变化。研究了具有不同化学成分（Ca / Si比1和2）以及不同合成工艺（双重分解和水热法）的C-H-H样品。加热后获得的结晶相通过显微拉曼光谱法鉴定，证实形成了与初始钙/硅比相同的无水硅酸钙。在Ca / Si比超过1.5的CS凝胶中，形成了稳定的Ca（OH）₂。扫描电子显微镜/能量色散X射线分析分析确定，在用激光加热的过程中，水分快速流失，从而形成多孔结构。Ca / Si比较低的材料的孔隙率较高。