Characterization of clay bricks surface deformation behavior through digital image analysis

Abstract

Handmade compacted clay bricks are an important integral building material especially for the low cost durable and affordable housing segment. Characterisation of physical, mechanical and deformation behavior of handmade clay bricks is essential to ensure material integrity and durability. In this paper, physical and mechanical properties are determined and the Particle Image Velocimetry (PIV) method is used to assess deformation behavior of bricks under uniaxial compressive loading. The bricks exhibit brittle failure with high strain localized along the cracks. The initiation and development of cracks on loading redistribute compressive strain within the brick with some regions experiencing minimum strain at failure. The relatively large displacements between cracks account for relatively large failure strain for the brittle bricks. A good concurrence is established between the strain assessment based on uniaxial compressive test and on image correlation using the PIV method. The average vector magnitude derived from PIV measurements, correlate well with the engineering strain and can thus be used for strain estimation in handmade clay bricks.