Experimental Study on Liquefaction Characteristics of Saturated Sands Mixed with Fly Ash and Tire Crumb Rubber

Abstract

The liquefaction of saturated sandy soils during dynamic loading can inflict excessive damage on the structures, leading to significant human and economic losses. Recycling and reusing industrial waste materials may offer a sustainable and economic solution to this problem. This study investigates the influence of two waste materials, namely, recycled fly ash and tire crumb rubber, on the liquefaction characteristics of sand. For this purpose, loose and medium-dense triaxial specimens were prepared using sand–fly ash mixtures containing 0–40% of fly ash and sand–tire crumb rubber mixtures containing 0–30% of crumb rubber. The liquefaction characteristics of the specimens were examined through a series of stress-controlled, undrained, dynamic triaxial tests. The tests were conducted at 1 Hz loading frequency and under initial effective confining stresses of 50 and 100 kPa. The experimental results showed that, at a similar relative density, the liquefaction resistance of the sand–fly ash specimens decreased as the fly ash content (FA) increased up to about 20%; then, it slightly increased until FA reached 40%. Sand-only specimens showed greater liquefaction resistance than sand–fly ash specimens. The liquefaction resistance of the sand–tire crumb rubber specimens was enhanced by increasing the rubber content (RC) in the mixtures. It was found that the increasing liquefaction resistance of sand with the addition of tire crumb rubber was more noticeable under higher confining stresses.