Effect of Organic Matter Content and Binder Quantity on the Uniaxial Creep Behavior of an Artificially Stabilized Soil

The objective of this work is to analyze, based on the results of uniaxial creep tests, the effect of organic matter content and binder quantity on the creep behavior of a Portuguese soft soil chemically stabilized with binders. In general, the results show that the application of a creep load induces a slight degradation of the mechanical properties of the composite material of the same age, as a consequence of the break-age of some cementation bonds owing to the creep deformation. This degradation grows with the increases in binder quantity and the decreases in organic matter content. The uniaxial creep tests indicate an increase in the creep strain rate with log time, allowing the definition of two creep compression indices, C-alpha 1(*) and C-alpha 2(*). Whereas the initial creep compression index (C-alpha 1(*)) is independent of the strength and shows a low scatter of values (0.00013-0.0003), the final creep compression index (C-alpha 2(*)) decreases with the increment of the strength, i.e., for higher binder quantities and lower organic matter contents. The results also reveal that the ratio C-alpha 2(*)/C-alpha 1(*) is almost unchangeable, 2.0-3.0. (C) 2014 American Society of Civil Engineers.