浅谈如何降低煤矿井下喷浆回弹率
浅谈如何降低煤矿井下喷浆回弹率
摘要：目前喷浆支护在煤矿井下已得到广泛使用，技术已较完善，但在实际施做中，回弹率高这一现象一直都困扰着广大煤矿技术、生产工作者。现在的煤矿井下喷浆回弹率普遍在30%以上，过高的喷浆回弹，造成施工现场粉尘含量大量增加，严重损害着现场职工的身体健康，同时，还造成大量的材料浪费，大大的增加了工程成本。如何有效降低喷浆回弹率，保护职工健康，降低施工成本，就必须要了解喷浆工艺及材料，找到造成回弹高的成因后对症下药。
关键词：降低;煤矿井下;喷浆回弹率 ; 成因; 处理
Abstract:Shotcrete support is currently in the coal mine has been widely used, the technology has been more perfect, but in actual, high rebound rate this phenomenon has been plagued by large coal mining technology, the production workers. Now of the coal mine spray resilient rate in more than 30% generally, shotcrete springback is too high, causing a huge increase in the construction site dust content, serious damage to the field worker’s health, at the same time, also caused a lot of waste materials, greatly increase the project cost. How to effectively reduce the shotcrete, resilient rate to protect worker health, reduce the construction cost, it is necessary to understand shotcrete technology and material, suit the remedy to the case after finding the cause of the high rebound.
Keywords: to reduce; the coal mine; guniting resilient rate; cause; to deal with
1．造成喷浆回弹率高的成因
1．1材料影响
（1）混凝土骨料配比不合理、含砂率低，粗骨料过多，大粒径多。
（2）所用砂、石含泥量、晒粉量不达标。
（3）水泥、速凝剂品质不合格，不新鲜，型号不配套。
（4）网片网孔太小，造成喷料不易与岩面粘结。
1．2施工工艺影响
（1）风压不合适，过大、过小或忽大忽小。风压过大，喷料从喷嘴射出时动能过大，使混合料扩散分离，粗骨料接触喷面时也易弹回；风压过小，粗骨料喷不到砂浆层就掉落；风压忽大忽小，容易造成出料不均，无法准确控制水灰比。
（2）水压、水量不合适，过大会使水灰比过大，出现喷料流淌；过小喷料出现干湿不均，无法有效粘结。