Spalling Resistance of Hybrid Polyethylene and Steel Fiber-Reinforced High-Strength Engineered Cementitious Composite

Abstract

AbstractWe analyzed the effect of elevated temperatures on the integrity of high-strength engineered cementitious composite (ECC) made with a hybrid combination of polyethylene (PE) and steel fibers. The 50 mm cube specimens were subjected to temperature ranging from 200 to 800 °C at three different heating rates: 1, 5, and 10 °C/min. Five different types of mixes with varying content of supplementary cementitious materials and fibers were evaluated. No spalling was observed at 1–5 °C/min heating rate and <400 °C. However, at a heating rate of 10 °C/min for temperature 600–800 °C, all ECC specimens with a PE fiber volume of 1.25 and 1% steel fiber spalled explosively. Moreover, cementitious matrix with silica fume was more prone to spalling at 800 °C and the use of slag or quaternary blend of slag and dolomite at an optimum content was effective in maintaining the integrity of the ECC specimens even at very high heating rates. Thus, the type of cementitious matrix is equally important to consider, as well as fiber type and content, while analyzing the spalling resistance of ECC.