引气剂和聚丙烯纤维对高水材料性质的影响研究

Research on influence of air entraining agent and polypropylene fiber on properties of high-water-content material

为了改变高水材料的破坏特点,采用引气剂和聚丙烯纤维双掺对其进行改性。试验结果表明:随着引气剂掺量的增加,浆体的流动性逐渐降低,混合浆液失流时间延长,试块密度和单轴抗压强度逐渐减小;聚丙烯纤维的掺入,对浆体流动性、失流时间、引气率影响均较小。聚丙烯纤维最佳掺量为2 kg/m3,引气剂和聚丙烯纤维的掺入使硬化体的弹性模量略有减小,且使试块由脆性破坏转变为延性破坏,在保持整体不散的情况下,提高其压缩量。SEM观察表明:钙矾石在气泡壁上集中生成,聚丙烯纤维与基体的界面处有利于针状钙矾石的生成,从而使聚丙烯纤维更好地发挥增强增韧的作用。

To change the broken characteristics of high- water- content material（ HWCM）,it was improved through mixing air entraining agent（ AEA） and polypropylene fiber（ PF）. The experimental results showed that： with the increase of AEA dosage,the fluidity of slurry gradually decreased,the lost flow time of mixed slurry prolonged,and the block density and uniaxial compressive strength gradually decreased. PF had a little effect on the fluidity of slurry,the lost flow time and the air entrainment percent,and the optimal dosage of PF was 2 kg / m3. AEA and PF made the elastic modulus of hydrated slurry decrease slightly,and they changed the brittle fracture of block to ductile fracture,and the amount of compression increased when it remained a whole in the course of compression. The SEM observation showed that the production of ettringite focused on the wall of bubble,and the production of needle- shaped ettringite was favorable at the interface of PF and hydrated slurry,which contributed to the reinforcing and toughening action of PF.