Cold-Weather Concreting Technology for Ground Modification

This paper describes the application of cold-weather concreting technology to soil stabilization with cement. For concrete, the typical approach involves the use of chemical additives to depress the freezing point, accelerate the curing process and initiate other changes that allow cementitious reactions to proceed at low temperatures. Likewise, cementitious reactions are also critical to the performance of cement soil stabilization. To that end, a set of experiments was conducted to evaluate the influence of three commercially-available chemical additives on the unconfined compressive strength of a local soil stabilized with 6% cement by weight. In particular, the chemical additives were tested at three dosage levels, with strength measurements taken at 1, 7 and 28 day curing periods, and two different curing temperatures. The control (unmodified) mixture resulted in an average 7-day strength of 295 kPa (42.8 psi) when cured at –2°C (28.4 °F). For the same mixture at the same curing temperature, the average 7-day strength increased to 1318 kPa (191 psi), 1050 kPa (152 psi) and 1332 kPa (193 psi) for the Gilco, Polarset and Daraccel brand chemical additives, respectively. As tested, the incremental cost associated with using these additives varied from 8–41%, making them a viable alternative to extensive undercutting and/or geosynthetics.