Mechanical characterization and numerical modeling of adobe walls with additives in normal and interlocking configurations

Abstract

Adobe construction system is one of the widely practiced construction systems worldwide. Many historical cities and monuments use adobe units to construct load bearing walls. Adobe units could be found either produced solely using clay or with some additives to enhance mechanical characteristics. Field investigations and inventories reported from across the world confirm that mechanical characteristics of adobe units vary significantly even within the same region, despite having little to no variation in size. Meanwhile, following empirical observations and knowledge of material behavior, the application of additives in adobe unit production has gained momentum for quite some time now. To assess the contribution of additives in the compressive behavior of adobe units and the lateral load response of adobe walls, we performed an extensive experimental campaign considering different extents of lime, cement, sawdust, jute fibers, and coconut fibers as additives. The lateral load response of adobe walls with normal and interlocking units is experimentally quantified for single and double wythed configurations. Numerical modeling is also performed to quantify the lateral load-deformation response and failure mechanism in adobe walls. Both experimental and numerical results conclude that toppling failure is the most governing failure mode in adobe walls with or without additives. The sum of observations highlights that 10 % sawdust as an additive enhances the lateral load response of adobe walls most effectively compared to other additive based normal and interlocking adobe walls. Similarly, 10 % cement additive is the most efficient in enhancing the compressive strength of adobe units. Thus, 10 % sawdust and 10 % cement can be considered respectively for lateral and compressive strength enhancements in adobe constructions.