挤压脱水与普通浇筑成型纤维水泥板性能对比

Comparison of the Properties of Fiber Reinforced Cement Boards Made with Extruded Dewatering and Ordinary Casting Methods

研究了挤压脱水成型与普通浇筑成型方法对纤维增强水泥板收缩及抗弯性能的影响.结果表明:在相同水灰比下,挤压脱水成型的纤维增强水泥板比普通浇筑成型的纤维增强水泥板收缩小,且其收缩发展速率比后者快;2种成型方法对PP纤维增强水泥板的力学性能影响不大,但对PVA纤维增强水泥板力学性能有一定影响,其影响程度与水灰比有关;无论是抗弯承载力还是抗弯延性,PP纤维增强水泥板均不如PVA纤维增强水泥板;对于普通浇筑成型,随着水灰比的增加,纤维增强水泥板的极限抗弯承载力有所下降,而抗弯延性却有所改善.

The shrinkage and mechanical properties of fiber reinforced cement board made with extruded dewatering method and ordinary casting method were studied. It is found that the shrinkage of the extruded dewatering board is lower than that of ordinary casting board even if they have the same water to cement ratio. Meanwhile, the development of shrinkage with time is faster for the extruded dewatering board than that of the ordinary casting board. The processing method has little influence on the mechanical properties of the polypropylene（PP）fiber reinforced cement board, while it has some influence on the mechanical properties of the polyvinyl alcohol（PVA）fiber reinforced cement board. The mechanical properties, including both flexural strength and flexural ductility, of PVA fiber reinforced cement board are improved very much compared with those of PP fiber reinforced cement board even if the boards have the same fiber content.