Recommendation of TC RILEM TC 274-TCE: 3-point bending test procedure for earthen bricks—quality control of earth bricks for structural masonry by flexural strength

Abstract

Building with unstabilised earth bricks (EB) as units for structural masonry walls offers a sustainable alternative to mitigate resource depletion's negative impact and global warming. Using locally sourced earth for EB production is required to achieve these benefits. This leads to large variations in material composition. Consequently, quality control becomes critical to ensure adequate mechanical performance of the masonry units. In the framework of the RILEM TC 274-TCE, the characterisation of the flexural strength of bricks has been examined. A comprehensive inter-laboratory campaign involving seven laboratories across three countries was conducted, during which flexural tests were performed on 98 bricks. This article details the TC 274-TCE recommendations on the procedure to conduct a 3-point bending test on an EB. Key test parameters such as specimen pre-conditioning, setup boundary conditions, loading rate and determination of material flexural strength are discussed. The calculation of flexural strength was evaluated by comparing results obtained from the beam theory model and a solid mechanics approach, validated through finite element modelling. The findings confirm that the 3-point bending test is a reliable method to assess the mechanical performance of EB and to control their quality.