Compressive strength of rammed earth filled steel tubular stub columns

Abstract

Rammed earth (RE) is a potential sustainable building material applicable for modern composite construction. To expand its potential application scenarios, this paper proposes RE-filled steel tubular (REFST) columns: using RE as the infill confined by external steel tubes. Uniaxial compression tests on both material and member levels are conducted. At the material level, cement-stabilized RE cylinder samples with two RE compositions and four levels of cement content are designed. Addition of cement significantly enhances the axial capacity of RE. A method to estimate the compressive strength of RE with considering the added cement content is proposed. Following the same RE composition and cement content at the member level, 15 REFST columns are axially compressed. The comparative study results show that confinement effect needs to considered in estimating maximum axial compressive strength of REFST columns and the strength ratio between the steel tube and infill RE is suggested to be no larger than 10 to fulfill the confinement effect. Finally, a method is proposed to predict the maximum compressive strength of REFST columns.