Experimental Study on Guabirotuba’s Soil Stabilization Using Extreme Molding Conditions

The porosity/cement ratio (η/C_iv) was employed in this research to study the evolution of unconfined compressive strength (UCS or q_u) and split tensile strength (STS or q_t) of a silty soil stabilized with cement in several molding conditions not shown in the literature. Five molding moisture contents (ω) fixed between 14.67 and 33.34%, three dry unit weight of molding between 13 and 16 kN/m³, four cement contents (C) between 3 and 9% (by dry mass of the natural soil) and a curing time of 28 days were used to study the influence of η/C_iv on q_t and q_u under normalized conditions. With the increase in dry molding unit weight and cement content, as well as reducing the initial porosity of the samples, q_u and q_t strengths increase for all mixtures. On the other hand, q_u and q_t also increase potentially depending on the η/C_iv ratio, adjusted to an exponent of 0.44, which remained constant for all molding conditions. The η/C_iv ratio was able to establish empirical ratios between q_t/q_u, which obtained values between 0.135 and 0.163 and which depended on the moisture content used during compaction. Regarding molding moisture content, there was an augment in q_u and q_t, with an increased molding moisture content up to 28% (converting into an optimum value) using the η/C_iv ratio in normalized terms. After ω = 28%, the strength of the mixtures was reduced. Finally, two equations to dose and estimate q_t and q_u were obtained, set to 96.5%, and with a 6% error. Thus, all strengths showed the same normalized potential trend as a function of ω, compatible with the value of η/C_iv^0.44 = 35.