Influence of Positive Temperature Cycling on Mechanical Properties and Microstructure of Concrete
LI Muyang
DONNG Yun
ZHANG Lu
ZHANG Zhenshan
Abstract：The effects of thermal cycling on the compressive strength,splitting tensile strength,water absorption and pore structure of C45,C60 and C90 concrete under 40-90℃and 40-200℃were investigated.The mechanisms by which thermal cycling affects the mechanical properties and microstructure of concrete were elucidated.The results demonstrate that under 40-90℃thermal cycling,the hydration process of concrete is accelerated,leading to a significant enhancement in mechanical properties.After 90 cycles,the compressive strength of C45 concrete increases by up to 41.5%.Under 40-200℃thermal cycling,the quantity of certain hydration products decreases,and the strength initially improves but then declines with increasing cycles.Due to lower hydration degrees and a more porous internal structure,the mechanical property of low-strength-grade concrete is more significantly affected by thermal cycling.As the number of thermal cycles increases,the concrete structure becomes looser,the number of internal pores rises,and the proportion of harmful and multi-harmful pores within the pore structure increases.
Keywords：self-compacting concretethermal cyclingmechanical propertypore structuremicroscopic mechanism
Publication Date：2026-01-31
Online Publishing Date：2026-03-17(First online date of this platform, not the publication date of the document)
Pages：8( 59-66 )