Uniaxial and triaxial failure strength of fiber reinforced EPS concrete

Abstract

EPS concrete is a relatively new lightweight building material with a combination of favorable properties. Available experimental results have shown that, for low volume contents of EPS, the presence of lightweight beads reduces strength more than density. This fact has led a few researchers to try to reinforce EPS concrete with fibers to partially compensate the strength loss. In this regard, the current study examines the simultaneous effects of EPS beads and polypropylenee fibers on tensile splitting, uniaxial compressive, and confined behavior of concrete by running 160 tests on cylindrical specimens. The results of different tests consistently showed that the strengthening effect of fibers is noticeably improved at higher EPS volume contents. For example, adding 0.5% of PP fibers increased uniaxial compressive strength by 35.5%. However, the maximum strength improvement of samples containing 5 and 10% of EPS beads was achieved at noticeably lower fiber contents of 0.1% and was only equal to 12.1 and 10%, respectively. The reasons behind the new findings are elaborated and justified using the micrographs of fracture surfaces from different samples. It is also found out that, compared to uniaxial compression, the strength weakening effect of EPS is increased by about 10 percent for highly confined loading conditions.