Behavior of compacted soil-fly ash-carbide lime mixtures

Unconfined compression tests, Brazilian tensile tests, and saturated draine d triaxial compression tests with local strain measurement were carried out to evaluate the stress-strain behavior of a sandy soil improved through th e addition of carbide lime and fly ash. The effects of initial and pozzolan ic reactions were investigated. The addition of carbide lime to the soil-fl y ash mixture caused short-term changes due to initial reactions, inducing increases in the friction angle, in the cohesive intercept, and in the aver age modulus. Such improvement might be of fundamental importance to allow s ite workability and speeding construction purposes. In addition, under the effect of initial reactions, the maximum triaxial stiffness occurred for sp ecimens molded on the dry side of the optimum moisture content, while the m aximum strength occurred at the optimum moisture content. After 28 days, po zzolanic reactions magnified brittleness and further increased triaxial pea k strength and stiffness; the maximum triaxial strength and stiffness occur red on the dry side of the optimum moisture content.