大孔隙再生混凝土及其细观组成的抗冻性与影响因素关联分析OA

To quantify the correlation between freeze-thaw resistance and its influencing factors in macroporous recycled concrete(MRC)and its mesoscopic constituents—recycled aggregate(RA),new paste(NP),and interfacial transition zone(ITZ)—saturated specimens of RA,NP,ITZ,MRC and paste-coated single aggregate were subjected to freeze-thaw tests in air.Multiple properties and parameters of each kind of specimen were measured under different numbers of freeze-thaw cycles,and grey relational analysis was employed to quantify the correlations among the test results.The relational degree rankings of influencing factors were identified as follows:For NP compressive strength,NP indentation elastic modulus>NP pore size distribution coefficient>NP average pore size;For ITZ shear strength,ITZ indentation elastic modulus>ITZ thickness;For old paste(OP)detachment rate,OP average pore size>ITZ thickness>OP pore size distribution coefficient>ITZ indentation elastic modulus>OP indentation elastic modulus;For MRC compressive strength,NP compressive strength ≈ ITZ shear strength>OP detachment rate.The relational degrees of all factors ranged from 0.503 to 0.955,indicating significant correlations.The strength of the NP and ITZ were strongly influenced by indentation elastic modulus,while the OP detachment rate was determined by weak points in the RA.When the porosity is around 25%,the influence of the material and the pore structure on the compressive strength of MRC reaches its peak and minimum,respectively.