Freeze-Thaw Performance Trends of Short-Term Cured Cement-Stabilized Aggregate Quarry By-Product Materials

Recent research studies conducted at the Illinois Center for Transportation focused on sustainable applications of quarry-by-products (QB) as pavement foundation materials and demonstrated the superior durability performance of dolomitic aggregate materials exposed to long-term cementitious reaction and repeated freezing and thawing. This study investigated the influence of QB chemical composition on the strength of cement-stabilized samples exposed to freeze-thaw cycles. Dolomitic QB materials from different quarries in Illinois and with different magnesium oxide (MgO) content, and a control limestone sample were chemically characterized by X-ray fluorescence and X-ray diffraction techniques. The QB materials were then stabilized with 3% cement and subjected to a 7-day curing period, followed by freeze-thaw conditioning. Unconfined compressive strength and resonant frequency tests were conducted to examine how the percentage of MgO and dolomitic minerals could alter the strength/stiffness with freeze-thaw cycles. Optical microscopy analysis was also performed to observe the extent of microstructure damage with freezing and thawing. Over the course of the applied freeze-thaw cycles, no notable minerology effect on strength or stiffness characteristics was observed for the short-term curing. Instead, performance was predominantly governed by physical properties, such as the particle size distribution, which played a more significant role after short-term curing. Well-graded QB materials with optimum packing, following Talbot's equation with a 0.45 exponent, consistently exhibited the highest strength after any freeze-thaw cycle. The next phase of research, focusing on long-term curing, is expected to provide more insights into the chemical and mineralogical effects of QB materials on durability performance.