粉煤灰—玄武岩纤维改良膨胀土试验研究

Experimental Study on the Strength of Reinforced Expansive Soils with Fly Ash-basalt Fiber

作为20世纪的重大发明,加筋技术被广泛应用于实际工程,取得了巨大的经济和社会效益。随着经济的高速增长,我国的路网等级和密度不断提高,公路膨胀土问题越来越严重。粉煤灰改良膨胀土的应用十分广泛,但是利用粉煤灰改良中强膨胀土的效果并不理想。将4种不同百分比(0%、0.15%、0.3%和0.45%)的玄武岩纤维分别均匀掺入到最优掺灰率为20%的膨胀土中,配制试样,通过试验研究不同纤维含量,不同养护龄期,不同围压对加筋灰土的影响。试验结果表明:与粉煤灰改良膨胀土相比,玄武岩纤维加筋灰土的强度有很大提高,自由膨胀率明显减小;同时可以确定灰土的最佳加筋率为0.3%。

Reinforcement technology which has made tremendous economic and social benefits is widely used in practical engineering as an important invention in twentieth Century. The expansive soil problem is becoming more and more serious with the network level and the density of our country continues to be improved by the rapid economic growth. Expansive soil is modified by the fly ash widely used,but the effect of modified expansive soil is not ideal. In this paper,four kinds of different percentage（ 0%,0.15%,0.3% and 0.45%） of basalt fiber are evenly mixed into expansive soil of the optimal ratio of fly ash is 20% to prepare for samples,through the experimental study of different fiber content,different curing ages,the different effects of confining pressure on the reinforced soil. The test results show that the strength of modified expansive soil by mixed the basalt fiber is greatly improved compared with the strength of fly ash modified expansive soil,the free expansion rate of modified expansive soil by mixed the basalt fiber is decreased; at the same time the best modified the ratio of basalt fiber is 0.3% in this paper.