The impact of hygrothermal factors on unreinforced alkali-reactive concrete

This article aims to simulate geomaterial alterations in hydraulic concrete constructions through experimentation. Three types of unreinforced concrete were identified (I, II and III), two of which (II and III) were alkali-reactive and doped with Na2Oeq, and were then compared with the control concrete (I). Then 27 cores were obtained from 9 beams following a three-point mechanical bending test. The conservation period of 28 weeks was in a heated and saturated environment 100% RH; 12-50°C. Additional treatment is only considered for the cores to investigate the internal concrete matrix and determine very short-term water absorption (24 to 48 hours), divided into three states: normal, dry, and saturated, an ultrasonic test NDT is planned during the treatment. The monitoring results demonstrate the following: 0.6% AAR expansion, 2 mm (CO) width crack opening; a 60% decrease in velocity. The statistical method (PCA) is used to elucidate the correlations between the experiment duration and pathological symptoms.