Out-of-plane structural response of interlocking compressed earth block walls

Stabilized compressed earth block (CEB) structures are popular in developing countries because of their low cost, sustainable use of indigenous materials, and inherent simplicity. Interlocking CEB blocks are dry stacked (no mortar in the joints), reinforced through flues and grouted. CEBs are typically used for single story homes and school houses. The current design practice for CEB structures in regions with severe natural hazards (typhoons and earthquakes) is questionable in terms of structural integrity. This is accentuated by the complete lack of experimental out‐of‐plane load testing of CEB walls. Scientific evidence reported in this paper has the potential to improve the current design practice to make this a safer construction form. Five CEB walls were built according to current design practice in Indonesia and Thailand, and subjected to out-of-plane loading. Two walls were full-scale panels and the remaining three walls were 1.1 m tall. All tests showed flexure dominated behavior, except for one full scale wall in which shear dominated failure was observed in the stiffening element. Results from the experimentation showed that the CEB walls were relatively flexible, mainly due to slack in the dry-stack joints, and that the current US masonry design code procedures (MSJC-11, Building code requirements for masonry structures (TMS 402-11/ACI 530-11/ASCE 5-11) (2011)) adequately predict the wall flexural strength. A moment–curvature based model was proposed for prediction of the out-of-plane force–displacement response and validated by the experimental results.