Variables influence on splitting tensile and unconfined compressive strength of two sedimentary stabilized-cement soils

ABSTRACT This paper evaluates the development of splitting tensile strength (qt) and unconfined compressive strength (qu) of two soils artificially cemented over 28 days. For this, two silty soils (yellow and purple) characteristics of the Guabirotuba Formation of Curitiba/Brazil were stabilized with initial high strength cement with percentages of 3, 5, 7 and 9% in reference to the dry mass of the soils. Specimens with 50 mm diameter and 100 mm high (volume of 196,35 cm3) were molded with the different cement contents (C), different molding dry unit weights (γd), and molding moisture (ω) constant at 23% and subjected to tests of unconfined compression and splitting tensile. The ratio of voids/lime represented by the porosity/volumetric cement content ratio (η/Civ) was used to evaluate the development of qu and qt in addition to variables such as C, η and γd. The results show an increase of the mechanical resistance with the increase of the cement content and with the decrease of the voids (i.e., higher specific dry weight and lower η). A dosing equation for qu and qt of the soils studied and mixed with cement was developed using the η/Civ ratio adjusted to an exponent 0,44 to make η/Civ-qu qt variation rates compatible. The dosage equations obtained coefficients of determination above 94%. Finally, an empirical constant of splitting/compressive ratio of 0,16 and 0,14 for the yellow and purple soil, respectively, was found.