ABSTRACT
Experimental research on the utilization of fly ash in road construction has been conducted for many years in the Laboratory of Highway Engineering of the University of Thessaloniki. The secondary material is a class C fly ash produced in large quantities and its stockpiling in the vicinity of the power stations constitutes a major environmental problem.
Research carried out in the field of highway engineering applications, herewith presented, was meant to provide technical solutions and guidelines for road construction. In this aspect, current practice consisting of material processing or mixing with Portland cement was not adopted for evaluation.
Soil-fly ash mixes, presenting different characteristics and varying in soil type, water content and binder content, were prepared and submitted to strength tests. Slurry type mixes, exhibiting compressive strength values of 125-500 kPa, are promising for use in grouting and relative applications. Stabilized soil mixes seem to perform adequately at low binder content, Rc = 2950 kPa, and very well at high binder content, Rc. = 7850 kPa, where, however, swell phenomena have to be faced.
The hydraulic binder tested seems to be appropriate for use in highway engineering applications, especially for treatment of poor subgrade or inadequate landfill material, providing cost-effective solutions.
