Micro- and Macro-scale Mechanical Properties of Meta-cherts as Concrete Aggregates

This paper presents the measurement of the tensile strength, Young's modulus, and linear coefficient of thermal expansion in a meta-chert. Two areas are targeted in this aggregate -a white area where quartz grains are densely compacted and a gray area where the quartz grains are coarser. The macro-and micro-scale data are compared. Young's modulus is not significantly different between macro-scale compression and micro-scale tension loading in the white region. Macro-scale splitting and micro-scale direct tensile strengths exhibit similar bimodal behavior due to the failure mechanisms of these two distinct areas. The macro-and micro-scale coefficients of thermal expansion are similar for the gray region, reflecting the quartz nature. Conversely, the micro-scale coefficient of thermal expansion of the white area shows a different behav-ior.