硅灰对机敏水泥砂浆抗压强度及压敏性的影响

The influence of silica-fume on compressive strength and press-sensitivity of smart cement mortar

碳纤维的分散性是影响机敏水泥砂浆电阻率稳定性的主要因素,在碳纤维长度分别为5mm和10mm、掺量分别为0.5%和0.9%的不同机敏水泥砂浆体系中,掺加不同量的硅灰,通过对体系抗压强度与压敏性研究表明,单掺硅灰没有提高纤维砂浆的抗压强度,反而使材料强度降低,掺量越多,抗压强度降低越多;细小的硅灰颗粒,可以填充在纤维间,提高碳纤维分散性,但它并不一定能改善材料的压敏性;提出有效间距的概念,指出只有当硅灰的掺入使得碳纤维间距在其有效间距内时,硅灰才能提高机敏水泥基材料的压敏性。

The dispersion of fiber carbon was deemed as the main factor to affect the resistance stability of smart cement mortar. Adding different amount of silica fume to smart cement mortar with fibers which length was at 5 mm and 10 mm and the volume was at 0.5% and 0.9%. The study results show that adding of silica fume did not improve compressive strength of fiber mortar. On the contrary,it decreases the mortar strength. The more the silica fume amount,the lower the compressive strength. Tiny silica fume powder distributed among the fibers averagely,whieh improved carbon fiher dispersive property,but it was not sure to improve press-sensitivity of the material. In this paper, a new conception of effective spacing is put forward,i.e, only the fume amount keeps the fiber carbon within effective spacing, can the silica fume improve the press-sensitivity of the smart cement-base material.