再生细骨料粒径及掺量对混凝土抗冻性能的影响

Effect of Particle Size and Content of Recycled Fine Aggregate on Frost Resistance of Concrete

采用快速冻融法研究了再生细骨料粒径、掺量以及粉煤灰对混凝土抗冻性能的影响.结果表明:再生细骨料混凝土的抗冻性能明显劣于相同配合比的基准混凝土;随着再生细骨料最小粒径尺寸减小、掺量增加,混凝土的抗冻性能下降,当再生细骨料最小粒径尺寸≤0.16mm,掺量≥40%(质量分数)时,混凝土抗冻性能下降很大;尽管再生细骨料混凝土的抗冻性能随着粉煤灰掺量的增加而有所下降,但掺粉煤灰后再生细骨料混凝土的抗冻性能仍明显优于未掺粉煤灰的再生细骨料混凝土,粉煤灰对再生细骨料混凝土的抗冻性能具有明显的改善作用.

The influence of particle size and content of recycled fine aggregate（RFA） as well as fly ash on frost resistance of concrete were studied by freezing-thawing test. The results indicate that the frost resist-ance of recycled fine aggregate concrete（RFAC） is inferior to normal concrete, it is deteriorated with de-creasing its minimum particle size and increasing its content. When the minimum particle size is smaller than 0.16 mm and the content is higher than 40% （by mass）, the frost resistance of RFAC significantly de-teriorates. The frost resistance of RFAC deteriorates with increasing fly ash content, but it is still good than that of RFAC without fly ash. This indicates that fly ash is good for RFAC to increase the frost re- sistance.