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矿用聚氨酯基加固材料稳定性研究

Study on stability of polyurethane reinforcement materials for mining

  • 摘要: 采矿工程中应用较广泛的化学注浆加固材料主要有聚氨酯和硅酸盐改性聚氨酯2类,一般均要求双组分体积比为1,但实际施工中不能严格控制体积比准确无误,且生产过程均不可避免存在一定称量误差。为确保注浆加固材料在井下施工中性能稳定可靠,在实验室条件下模拟研究了双组分配比失调和主要组分称量误差,对反应温度和固结体抗压强度、抗剪切强度、抗拉强度的影响。结果表明:主要组分在±5%称量误差下,2类加固材料固结体力学强度波动较小。2类材料双组分浆液配比失调10%以下时,其固结体力学强度降幅不大。当双组分配比失调20%时,聚氨酯材料抗剪强度和抗拉强度分别下降56.9%和72.7%,最高反应温度升高6 ℃,硅酸盐改性聚氨酯加固材料AB组分混合后出现发泡、出水、泛碱和难成型等问题。因此,改变2类加固材料配方时,除了研究标准规定的相关性能,还应探究其最大配比容错能力,施工中尽量保持正常配比,避免因配比失调引发安全问题。其中,聚氨酯加固材料使用中,谨防白料过量引发力学强度大幅降低,及黑料过量致使反应温度升高。对于硅酸盐改性聚氨酯加固材料,配比大幅失调会出现严重异常现象,难以达到正常加固效果。另外,主要组分称量误差对2类材料力学强度的影响较小。

     

    Abstract: The chemical grouting reinforcement materials that are widely used in mining engineering mainly include polyurethane and silicate modified polyurethane.Generally, the volume ratio of two components is required to be 1∶1, but the accuracy of volume ratio cannot be strictly controlled in the actual construction, and certain weighing errors are inevitable in the production process.In order to ensure the stable and reliable performance of grouting reinforcement materials in underground construction, the imbalance of two-component ratio and the weighing error of main components were simulated under laboratory conditions. The effects of the reaction temperature and the compressive strength, shear strength and tensile strength of the consolidated body were investigated. The results show that the main components are within ±5% of the weighing error, the mechanical strength of the consolidation of the two types of reinforcement materials fluctuates little.When the proportion of the two-component slurry of type 2 materials is less than 10%, the mechanical strength of the two kinds of materials decreases, but it does not affect the normal reinforcement effect. When the distribution ratio of the two-component was out of adjustment by 20%, the shear strength and tensile strength of polyurethane decreased by 56.9% and 72.7% respectively, and the maximum reaction temperature increased by 6 ℃.After the AB component of the silicate modified polyurethane reinforcement material was mixed, there would be problems such as foaming, effluent, efflorescence and difficult molding. Therefore, when changing the formula of Type 2 reinforcement materials, in addition to the relevant performance specified in the standard, the maximum ratio fault tolerance should be explored,the normal proportion shall be kept as far as possible during the construction to avoid safety problems caused by the imbalance of proportion.Among them, in the use of polyurethane reinforcement materials, we should be careful to prevent the mechanical strength from greatly reducing due to excessive white materials and the reaction temperature from increasing due to excessive black materials.For the silicate-modified polyurethane reinforcement materials, serious abnormalities will occur if the proportion is greatly misaligned, and it is difficult to achieve the normal reinforcement effect.In addition, the weighing error of the main components has little effect on the mechanical strength of the two types of materials.

     

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