Partially grouted reinforced masonry (PG-RM) shear walls have a vast presence in many countries, even in seismic-prone regions. These walls have had acceptable seismic performance in strong earthquakes, although in-plane shear failures have been reported. Although past studies have addressed some of the detected issues, experimental information is still limited, a situation even more notorious when focusing on bed-joint reinforced (BJR) PG-RM shear walls. Besides, most numerical approaches proposed for analyzing masonry elements are aimed at reproducing unreinforced masonry elements. Additionally, recent studies have demonstrated the inaccuracy of some design codes and some existent expressions when estimating the shear strength of PG-RM shear walls. Therefore, it is necessary to gather further experimental data on PG-RM shear walls, improve or adapt numerical approaches to study them, and also propose suitable formulas to estimate their in-plane shear resistance. In response to the identified necessities, 18 full-scale PG-RM shear walls were tested under constant axial load and incremental in-plane lateral cyclic loading. Nine walls were built with multi-perforated clay bricks (MPCBLs), and nine with hollow concrete blocks (HCBs). Different design properties were varied, such as the walls’ geometrical properties, reinforcement ratios, reinforcement layout, and material properties. All tested walls failed in a diagonal tension failure mode. In general, the studied variables affected the walls’ response. For instance, using lower aspect ratio or joint thickness; and higher axial load ratio, horizontal or vertical reinforcement ratio, or mortar compression strength produced a higher shear strength in the BJR-MPCLB walls. In BJR-HCBs walls, using a higher vertical or horizontal reinforcement ratio increased the shear strength and providing edge elements generated a more stable post-peak behavior. Additionally, in HCB walls, providing a combination of horizontal reinforcement embedded in mortar bed-joints and bond-beams resulted in better hysteretic behavior, energy dissipation capacity, and ductility compared to the walls provided with only one horizontal reinforcement type. Also, a numerical study on the implementation of detailed micro-models (DMMs) of PG-RM shear walls was performed. Good accuracy was obtained when reproducing the experimental behavior of the MPCLB walls tested in this study, being more accurate than the selected shear expressions. It is highlighted the importance of choosing an appropriate numerical solution strategy to avoid misleading results considering the strong non-linear response of these models. Then, DMMs were used to perform a parametric study on the influence of selected design variables on the shear response of PG-RM shear walls of MPCLBs. The results were also employed to corroborate a combined effect of the axial stress and aspect ratio on the walls’ shear strength. Besides, implementation details of simplified micro-models (SMM) of PG-RM shear walls of HCBs are given. Two identical BJR-PG-RM shear walls of HCB were reproduced with this approach, obtaining an appropriate accuracy. Finally, design expressions for estimating the resistance of bed-joint reinforced PG-RM shear walls of MPCLBs and HCBs were fitted to databases composed of experimental and numerical results. The obtained expressions are more accurate than the studied code expressions in terms of the error average and range.Resguardar información que no ha sido publicada en revistas especializadas