Effect of Curing Conditions on the Shrinkage of Ultra High‐Performance Fiber‐Reinforced Concrete

Abstract

e effect of curing conditions on the early age and long-term shrinkage of ultra high-performance fiber-reinforced concrete (UHPFRC) was systematically studied. e shrinkage of the early age (0-168 h) and long-term age (0-90 d) of UHPFRC material was measured based on three kinds of humidity conditions (dry, sealed, and soaked) and curing temperatures (25°C, 40°C, and 75°C), respectively. In this paper, the hydration degree of different shrinkage stages was studied in combination with chemicalbound water experiment. Meanwhile, the influencing mechanism of curing condition on the shrinkage of UHPFRC was analyzed.e results show that the early shrinkage rate of UHPFRC is accelerated with the increase of temperature, and the rate of shrinkage development at the latter stage is suppressed with the increase of temperature. With the increase of humidity, the early age shrinkage of UHPFRC and its increasing rate gradually decrease, which means drying condition > sealing condition > soaking condition. According to the long-term shrinkage results, increasing temperature has very significant inhibiting effect on the UHPFRC shrinkage in the sealed condition. Due to the majority of the in-site components of UHPFRC cured in the sealed condition, high-temperature curing has evident inhibition of early age shrinkage of UHPFRC. erefore, promoting curing temperature is fairly effective at inhibiting the early age shrinkage of UHPFRC for the in-site structures.

The Effect of the Morphology of Coarse Aggregate on the Properties of Self-Compacting High-Performance Fibre-Reinforced Concrete

“…Kostrzanowska-Siedlarz and Gołaszewski highlighted that the composition of the high performance SCC effect its rheological properties [ 1 ]. However, the methods of mixing and curing, together with the resistance of SCC to environmental conditions, are still under development [ 2 ]. Recently, the application of steel fibers has enabled the utilization of self-compacting high performance fibre-reinforced concrete (SCHPFRC).…”

Mitigation of the Factors Affecting the Autogenous Shrinkage of Ultra-High Performance Concrete

“…These methods considered the addition of other cementations materials to hinder the early hydration and reduce the associated heat like fly ash and met kaolin, using crushed ice and lightweight aggregate for the purpose of internal curing, and increasing tensile strength by steel fibers. Kamen [13] and Hanet et al [16] stated that the high initial curing temperature raised the rate of autogenously shrinkage. Yang et al [14] showed the approaches that can be followed to mitigate the autogenously shrinkage depending on restraining agents inside the structure of UHPC.…”

Influence of Rapid Heat Treatment on the Shrinkage and Strength of High-Performance Concrete

“…Heat treatment anticipates significant amounts of the basic shrinkage, since the cement largely hydrates already during the treatment [ 18 ]. The specific influences on shrinkage depend on many factors such as the concrete’s composition [ 12 ] and can vary greatly [ 19 ].…”