Early-age behavior and cracking resistance of high-strength concrete reinforced with Dramix 3D steel fiber

摘要

High-strength concrete (HSC) is widely used in practice, which is due to its potential benefits, such as good workability, long durability, low permeability. However, higher autogenous shrinkage occurs owing to the low water-to-cement (w/c) ratio of HSC, which would reduce the cracking resistance. Therefore, Dramix 3D steel fibers are applied to strengthen the early-age properties of HSC to increase the cracking resistance. Although investigations on the effect of steel fiber on the properties of HSC have been conducted, investigations on the effect of Dramix 3D steel fiber on the autogenous shrinkage, temperature history, restrained stress, mechanical properties, and cracking resistance of HSC remain lacking. In present study, Temperature Stress Test Machine (TSTM) was utilized to investigate the properties of HSC reinforced with Dramix 3D steel fiber at early age. The test results and corresponding analysis indicated that: (1) the absolute value of autogenous shrinkage of HSC decreased with the increase of the amount of Dramix 3D steel fiber, and a model for autogenous shrinkage was proposed; (2) the temperature or temperature drop at cracking time of HSC decreased or increased with the increase of the amount of Dramix 3D steel fiber; (3) the stress at room temperature, cracking stress, ratio of cracking stress to tensile strength, and stress reserve of HSC increased with the increase of the amount of Dramix 3D steel fiber; (4) the addition of Dramix 3D steel fiber improved the cracking resistance of HSC. (C) 2018 Elsevier Ltd. All rights reserved.