[关键词]
[摘要]
试验研究了水洗、NaCl、CaCl2 、KH560、KH 570、CCl4 六种改性方式对橡胶水泥砂浆抗压强度和劈拉强度的影 响变化规律, 其中水洗改性方式使橡胶水泥砂浆的抗压强度和劈拉强度分别提高了7. 6%和9. 9%; 无机改性剂中, NaCl 和CaCl2 对橡胶水泥砂浆强度的提高均是负面作用, 5% 浓度的NaCl 溶液改性作用与水洗相当, 使橡胶水泥 砂浆的抗压强度提高了8. 6%, 有机改性剂中KH 560 和KH 570 的效果优于CCl4 , 与基准橡胶水泥砂浆相比, KH 560 和KH 570 改性后的橡胶水泥砂浆的抗压强度分别提高了5%和4. 7%。分析表明, 无机改性剂对橡胶水泥 砂浆强度的影响机理复杂, NaCl 会在混凝土内部形成晶体压力, CaCl2 对水泥的水化反应有影响; 而有机改性剂 KH 560 和KH 570 可以改善橡胶颗粒与水泥石的粘结界面。
[Key word]
[Abstract]
The effects o f six surface modificatio n methods on t he compressive st reng th and split streng th of rubber cement mor tar wer e inv est igat ed. T he six metho ds include water w ashing , sodium chlor ide solution, calcium chlor ides solution, KH560 so lu2 tion, KH570 solution, and CCl4 so lutio n. The method of w ater washing enhanced the compr essiv e strength by 7. 6% and com2 pressiv e streng th by 9. 9% of rubber cement mort ar. So dium chlor ide solut ion and calcium chlor ides so lutio n had neg ativ e effects on the str eng th of r ubber cement mor tar. Sodium chlo ride so lutio n of 5% concent ratio n enhanced the compr essive str eng th of rubber cement mor tar by 8. 6%, which w as similar to w ater washing. The effects o f KH 560 and KH 570 wer e bet ter than that of CCl4 in the o rg anic mo difiers, and the com pr essiv e st reng th of r ubber cement mo rtar w as increased by 5% and 4. 7% using the KH 560 and KH 570 so lutions respect ively compared w ith that of the unmodified rubber cement mo rtar . The r esults sug gested that t he im pact mechanism o f inorg anic modifier s o n t he str eng th of r ubber cement mor tar is complex . Cry stal pr essure can be formed in the co ncr ete caused by NaCl and the hydrat ion r eact ion caused by CaCl2 can be harmful to the cement. The o rg anic modifier s, such as KH 560 and KH 570, can amelior ate the int er face betw een the rubber and cement paste.
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[基金项目]
水利部公益性行业科研专项( 201301027)