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

Abstract

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.