Axial capacity of grouted compressed earth block load-bearing walls with reinforced micro-columns: an experimental and numerical investigation

Owing to their environmental benefits, use of locally available materials, and relatively low construction cost, compressed earth blocks (CEBs) represent a sustainable alternative to conventional masonry materials. However, the added strength of reinforced and grouted block cores is not sufficiently represented in existing design approaches, which has limited their use in structural construction. The present study addresses this limitation by developing a design equation for load-bearing walls made of grouted CEBs. The proposed method is based on experimental research and numerical simulations that take into account the key structural and material factors. Characterization of CEB properties, prism testing, and full-scale wall tests using reinforced grout micro-columns were all part of the experimental program. The results demonstrated that reinforced grout micro-columns significantly enhance the structural performance of CEB walls, and grouting the hollows inside the blocks could greatly increase the load-carrying capacity. Effective participation coefficients for the CEB matrix, grout, and reinforcement were calibrated from the experimental results. Based on the experimental results, the allowable design participation coefficients of X = 0.16, Y = 0.43, and Z = 0.44 were obtained for the CEB matrix, grout, and reinforcement, respectively (while the corresponding ultimate coefficients are 0.31, 0.81, and 0.83). The number of reinforced micro-columns is taken into consideration in the proposed design equation, which also includes a slenderness reduction component to account for the impact of wall geometry on axial resistance. A finite-element model comprising the masonry, grout, reinforcement, and their interaction behavior was developed in ABAQUS to assess the proposed formulation. The numerical model reproduced the principal experimental response and provided supporting evidence for the proposed equation. The resulting equation provides a practical way to assess the axial resistance of grouted CEB load-bearing walls by explicitly accounting for the contributions of the CEB matrix, grout, reinforcement, and wall slenderness. The results also identify the critical factors that require further investigation to extend the applicability of the proposed formulation to a wider range of CEB wall layouts.