Use of the digital image correlation and acoustic emission technique to study the effect of structural size on cracking of reinforced concrete

•Image correlation and acoustic emission techniques are simultaneously applied.•Bending tests are performed on reinforced concrete specimens.•Experimental crack openings and crack spacing are compared with Eurocode2.•Acoustic energy analysis is performed to characterise damage intensity in concrete.•Failure occurs in shear as well as in tension in all the three sizes of beam.

An experimental investigation is performed to study the degradation of reinforced concrete beams by employing two experimental techniques simultaneously i.e. digital image correlation and acoustic emission. The former method gives very precise measurement of surface displacements, thus crack openings and crack spacing are determined. In order to complement this method and to investigate damage mechanisms, acoustic emissions resulting from internal damage are also analysed. Beams of three different sizes but proportionally similar, are tested to study the effect of structural size. A comparison of the experimental measurements with Eurocode expressions is also presented.