This study experimentally investigated how to make 300N/mm2 ultra-high-strength concrete. The fine aggregate type was found to significantly influence compressive strength development, and the use of quartz fine aggregates yielded the highest strength. The strength of the mortar specimens made of blended cement containing silica fume reached 350〜400N/mm2 with a two-stage heat curing scheme. For concrete, the type and maximum size of coarse aggregates greatly affect the strength; the use of rhyolites up to 10mm resulted in approximately 300N/mm2. The use of homogenous high-strength aggregates does not necessarily yield high concrete strength, likely due to the difference in Poisson’s ratio.
