固化粉煤灰在台背回填中的应用研究

Analysis on Application of Solidified Fly Ash in Abutment Backfilling

为了研究固化粉煤灰的适用性,对不同固化剂掺量下的固化粉煤灰击实特性、强度与水稳定性、碾压特性以及板体性通过室内试验进行了相关研究。结果表明:在相同的碾压条件下,固化粉煤灰的密度约为常规填筑材料的72%,对地基至少可减少25%的附加应力,从而产生的沉降更小。当压实度为95%时,不同固化剂掺量下的28 d抗压强度均不低于2.0 MPa,利于缩短工期、早日开放交通。不同龄期下、不同固化剂掺量下固化粉煤灰的水稳定系数均不小于0.8;固化粉煤灰的抗压回弹模量远高于传统台背回填材料,具有良好的板体性。固化剂掺量宜取7%~8%,提出了固化粉煤灰填筑台背的质量控制要点。

Under different dosages of curing agent, the compaction characteristics, strength, water stability,rolling characteristics, and plate performance of solidified fly ash were studied by laboratory tests to analyze the applicability of the solidified fly ash. The results show that, under the same rolling condition, the density of the solidified fly ash is about 72% of that of conventional filling materials, and the additional stress on the foundation could be reduced by at least 25%, resulting in less settlement. When the degree of compaction is 95%, the compressive strength of 28 days under different dosages of curing agent is not less than 2.0 MPa, which is beneficial to shorten the construction period and open the traffic. The water stability coefficient of solidified fly ash under different ages and different dosages of curing agent is not less than 0.8. The compressive resilience modulus of solidified fly ash is much higher than that of conventional backfill materials, which shows good plate performance. The appropriate dosage of curing agent is 7% to 8%. This paper proposed key points of quality control for filling the abutment with solidified fly ash.