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       攪拌機在混凝土制備流程中擔負均勻混合的重任，攪拌是混凝土質量控制重要一環。本文從攪拌機葉片與攪拌軸之間的角度以及混凝土在攪拌機內的拌合時間出發，探討攪拌機葉片角度及攪拌時間對混凝土效果的影響。
 

     葉片角(jiao)度對攪拌效果的影響(xiang)
     葉片(pian)角度(du)是指攪(jiao)拌(ban)葉片(pian)與攪(jiao)拌(ban)軸(zhou)(zhou)(zhou)之間(jian)所(suo)夾(jia)的銳角，其對骨料周向(xiang)(xiang)和軸(zhou)(zhou)(zhou)向(xiang)(xiang)運動速度(du)產(chan)生(sheng)重要(yao)影響。當葉片(pian)角度(du)為0°時(shi)，葉片(pian)與攪(jiao)拌(ban)軸(zhou)(zhou)(zhou)處于平行狀態，骨料在葉片(pian)推動下以攪(jiao)拌(ban)軸(zhou)(zhou)(zhou)為圓心僅做圓周運動，無軸(zhou)(zhou)(zhou)向(xiang)(xiang)分力，不會產(chan)生(sheng)軸(zhou)(zhou)(zhou)向(xiang)(xiang)運動，此時(shi)即(ji)使攪(jiao)拌(ban)時(shi)間(jian)延長，攪(jiao)拌(ban)質量也不會得到提高(gao)。
　　
       在葉(xie)(xie)片(pian)角度從0-90°逐(zhu)漸增加(jia)過程中，在一定(ding)角度范(fan)圍內攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)骨(gu)(gu)料(liao)(liao)軸(zhou)向(xiang)(xiang)(xiang)速(su)度會變大(da)，但角度超過某(mou)一定(ding)值后，骨(gu)(gu)料(liao)(liao)軸(zhou)向(xiang)(xiang)(xiang)運動(dong)(dong)的(de)(de)速(su)度反而(er)會變弱，同時骨(gu)(gu)料(liao)(liao)做圓周(zhou)運動(dong)(dong)的(de)(de)速(su)度也(ye)會相(xiang)應變小，導致攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)質量(liang)(liang)較(jiao)差，攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)效率(lv)降低。當攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)葉(xie)(xie)片(pian)與攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)軸(zhou)夾(jia)角為90°時，攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)葉(xie)(xie)片(pian)與攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)軸(zhou)相(xiang)互垂直，等同于一個垂直攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)軸(zhou)的(de)(de)平板，此(ci)(ci)時攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)葉(xie)(xie)片(pian)對骨(gu)(gu)料(liao)(liao)只(zhi)產生(sheng)切割作用，失(shi)去對骨(gu)(gu)料(liao)(liao)的(de)(de)攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)作用。因此(ci)(ci)，只(zhi)有將攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)葉(xie)(xie)片(pian)與攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)軸(zhou)的(de)(de)夾(jia)角控制在適宜范(fan)圍內，才能(neng)保證骨(gu)(gu)料(liao)(liao)軸(zhou)向(xiang)(xiang)(xiang)和(he)(he)周(zhou)向(xiang)(xiang)(xiang)運動(dong)(dong)均能(neng)取得較(jiao)大(da)速(su)度，使骨(gu)(gu)料(liao)(liao)達到良(liang)好的(de)(de)攪(jiao)(jiao)(jiao)拌(ban)(ban)(ban)效果，滿足質量(liang)(liang)和(he)(he)效率(lv)要求。

      骨料攪拌(ban)時間對(dui)拌(ban)和物均勻性的影響
      骨料(liao)攪拌(ban)(ban)(ban)(ban)時間是(shi)指從原材料(liao)全部投入攪拌(ban)(ban)(ban)(ban)罐開始(shi)攪拌(ban)(ban)(ban)(ban)，至(zhi)攪拌(ban)(ban)(ban)(ban)停止(zhi)所用(yong)時間。為(wei)精確記錄混(hun)凝土(tu)骨料(liao)在攪拌(ban)(ban)(ban)(ban)機(ji)內的攪拌(ban)(ban)(ban)(ban)時間，采(cai)用(yong)秒表(biao)進行計時。根據相(xiang)關(guan)(guan)試驗資料(liao)和(he)生產經驗，混(hun)凝土(tu)拌(ban)(ban)(ban)(ban)和(he)物的均勻(yun)性隨攪拌(ban)(ban)(ban)(ban)時間的延(yan)長(chang)而提高。通(tong)過(guo)合(he)理減(jian)小葉片與攪拌(ban)(ban)(ban)(ban)軸角度(du)(du)，減(jian)緩骨料(liao)軸向速度(du)(du)，將(jiang)使骨料(liao)通(tong)過(guo)葉片滑移面和(he)剪切(qie)面得到很好(hao)的交換，使混(hun)凝土(tu)拌(ban)(ban)(ban)(ban)和(he)物均勻(yun)性得到良好(hao)改善。但攪拌(ban)(ban)(ban)(ban)時間也不能(neng)無(wu)(wu)限(xian)(xian)延(yan)長(chang)，當其超過(guo)某一限(xian)(xian)值后，混(hun)凝土(tu)的勻(yun)質性將(jiang)無(wu)(wu)明(ming)顯改善，且影響攪拌(ban)(ban)(ban)(ban)機(ji)的生產率，對混(hun)凝土(tu)的強度(du)(du)無(wu)(wu)益(yi)。所以，為(wei)保證混(hun)凝土(tu)拌(ban)(ban)(ban)(ban)和(he)物的均勻(yun)性，適當減(jian)小攪拌(ban)(ban)(ban)(ban)葉片與攪拌(ban)(ban)(ban)(ban)軸角度(du)(du)，合(he)理延(yan)長(chang)骨料(liao)攪拌(ban)(ban)(ban)(ban)時間至(zhi)關(guan)(guan)重要。
      在設備、原材料(liao)、操作規范、溫度等外界環境最優(you)條件(jian)下，骨料(liao)攪拌時(shi)間不(bu)(bu)足(zu)(zu)將導致(zhi)混凝土拌和物(wu)不(bu)(bu)均(jun)，采用(yong)減小(xiao)正向葉片與攪拌軸間角度的方法對攪拌機進行(xing)低成本改造，可提高攪拌機效(xiao)率、質(zhi)量標準，使混凝土均(jun)勻性滿(man)足(zu)(zu)控制要求(qiu)。