组成及龄期对复合粉煤灰/水泥浆Cl^-结合性能的影响

EFFECT OF THE COMPOSITION AND THE AGE ON THE CHLORIDE BINDING CAPACITY OF HYBRID FLY ASH/CEMENT PASTE

研究了组成和龄期对粉煤灰/水泥浆体系硬化水泥浆Cl^-结合能力的影响。首先研究了组成和龄期对粉煤灰和水泥二组分体系硬化水泥浆Cl^-结合性能的影响,并且确定了Cl^-结合量最大的组成比。在该硬化水泥浆Cl^-结合量的组成比例下继续以钠钙硅玻璃粉和Ca(OH)_2混合组成取代水泥,并采用正交试验设计,探讨了玻璃粉掺量、细度和Ca(OH)_2掺量对Cl^-结合性能的影响。结果表明,14d和28d龄期时,粉煤灰对水泥取代量为50wt%的硬化水泥浆Cl^-结合能力达到极大值。正交试验结果表明,在10wt%、20wt%、30wt%的三个水平中,玻璃粉的掺量对硬化水泥浆的Cl^-结合量的影响最大,有使硬化水泥浆Cl^-结合能力降低的作用,而Ca(OH)_2具有使Cl^-结合能力增大的作用。但掺加了玻璃粉和Ca(OH)_2的粉煤灰-水泥浆体系硬化水泥浆Cl^-结合量随龄期的延长而下降。从正交试验的结果来看,少量玻璃粉的掺入并配合使用Ca(OH)_2,有望对掺粉煤灰硬化水泥浆的氯离子结合起到促进作用。

The effects of the composition and the age of hybrid fly ash/cement paste on its chloride binding capacity were investigated in the paper. Firstly, the effects of the composition and the age on the chloride binding amount of paste in fly ash-cement binary system were investigated, and the composition at which the maximum chloride content of the hardened paste could be bound was determined. At this case, The effect of glass powder/Ca（ OH）2 replacement for cement was further discussed in the respects of the doping content, the fineness of glass powder and the doping content of Ca（0H） 2 by adopting an orthogonal experiment design. The results show that the chloride binding amount of the hardened paste that reaches its maximum was the case that the replacement of fly ash is the 50 wt % cement and the age is 14d or 28d. It is indicated that the effect of the replacement of glass powder for cement at the levels of 10 wt %, 20 wt % and 30 wt % is the most, reducing the chloride binding ability, but Ca（OH）2 re- placement enhances the chloride binding ability. However, the chloiSde binding amount of the hardened paste that is added with glass powder/Ca（OH）2 doped fly ash/cement paste has a decrease with the in- crease of the age. The orthogonal experimental results indicates that the low content of glass powder and the addition of Ca（OH）2 contributes to the improvement of chloride binding capacity of the fly ash/ce- ment hardened paste.