Load tests of short columns (L/h = 5) will be monitored to determine whether yielded steel will cause premature splitting of high strength concrete and if so, whether a closer spacing of ties can compensate for such splitting. concrete columns (f' 8 ksi) with reinforcement Grade 150 should experience crushing-spalling failure of concrete before steel yields. Load tests of short specimens (L/h = 5) will be monitored to observe the relationships that f' and spacing of transverse ties have on the useful range of steel stress that can be developed before concrete fails. Concrete columns with f' = 15000 psi and Grade 150 steel will be tested to observe performance when both materials are extraordinarily strong.
