Study of Cracking Pattern and Its Evolution on Natural Textile Reinforced Concrete by Image Analysis

Abstract

Textile reinforced concrete (TRC) is an emergent class of material with great deformation capacity and multiple crack formation. Natural fibers are a more eco-friendly alternative to synthetic textile and they are gaining attention in the construction field. In the present study, a Brazilian natural fiber, called curauá, is used in the form of uni-directional textile as reinforcement of cementitious matrix. The composites were manufactured with a hand lay-up technique, varying its thickness and fiber volume fraction. Three types of laminates were investigated under direct tensile tests and its cracking patterns were evaluated by distinct two methodologies. An image processing software was used on photos taken during the tests and a digital image correlation (DIC) technique was also used. The differences between the methods and their limitations are addressed. Parameters as crack spacing and mean crack widths are estimated. The more cracks the composite presented, the more difficult was to perform the measurements due to overlapping of strain fields by DIC. The image analysis performed by the software was able to estimate the number of cracks and the crack spacing for all three types of composites. The mean crack width during the tests was estimated from DIC data.