Thermal damage and its controlling methods of high‐speed railway steam‐cured concrete: A review

Abstract

The steam curing technology is worldwide applied in the production of concrete prefabricated components, including the production of track slab and girder used for the high‐speed railway in China. However, the steam curing process at elevated temperature will often generate the heat damage on concrete and thus degrade the long‐term performance of the steam‐cured concrete prefabricated components. It is very important to deeply understand the mechanism of heat damage and thus to find effective method reducing or avoiding the damage of steam curing on concrete. The main purpose of this paper is to systematically classify the types of thermal damages on concrete during the steam curing and its mechanism. The influences of main factors on three thermal damages such as the unrecoverable expansion deformation, the surface layer defect, and the embrittlement of the steam‐cured concrete are discussed in detail. The controlling methods of thermal damages including optimization of the steam curing regime and mixing proportions, the addition of supplementary additives, the self‐healing technology, and other curing technology are compared and summarized based on the literatures. Finally, suggestions for future research are proposed in order to effectively reduce or even avoid the thermal damage of the steam‐cured concrete. And also, some new technology for developing the green and high performance early strength concrete with low CO2 emission are presented.

Improve the long-term property of heat-cured mortars blended with fly ash by internal curing

“…By the way, the lowest open porosity/water absorption of HCM blended with LWFA and FA among four mixtures at 60 d indicates that the synergistic effect of them can substantially the surface microstructure of HCM. Actually, the improvement of surface property is meaningful to the engineering practice of heat-cured materials since they commonly encounter the issue of thermal damage, especially the surface [65][66][67]. A dense surface microstructure is beneficial to not only the strength but also the resistance to ion penetration.…”

Mechanical evolutionary behavior of steam‐cured concrete under the coupling effect of flexural fatigue and minus temperature

“…Another main function of steam curing is to improve the productivity and efficiency of molds 30 . Nonetheless, previous studies on the thermal effects of steam curing illustrated that the accelerated hydration of cementing material could cause the volume expansion, the surface micro‐crack, the crystallization of hydrates, and pore coarsening, 31–36 and thus resulted in the degradation in the long‐term durability of steam‐cured concrete 37 …”

A Comparative Study on the Mechanical Properties and Microstructure of Cement-Based Materials by Direct Electric Curing and Steam Curing

“…SC shortens the demolding times and to increases productivity, which improves the economic efficiency. However, many studies have suggested that SC has some adverse effects on specimens, such as coarsening of pores [9,10], thermal damage leading to cracking [11,12], reduction of long-term performance [13], and reduction of durability performance [14]. In response to the advantages and disadvantages of SC, a new direct electrical curing (EC) [15] method has been discovered by research scholars .EC uses fresh specimens with low resistivity [16] to generate uniform Joule heat under the current to accelerate the hydration of cement and enhance early mechanical properties.…”