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.