ADOBE BUILDINGS IN SEISMIC AREAS: INNOVATIVE SCIENTIFIC B.ESEARCII

The project aimed to understand the reasons behind the weak zones of adobe masonry, particularly in Peru, and to develop strategies for improving its strength and seismic resistance. The research team selected six soils from different regions of Peru, including Cajamarca, Cuzco, Huancayo, Huaraz, Pisco, and Lima, for laboratory testing. The soils were analyzed for their physical, chemical, and strength characteristics, including their reaction to hydrochloric acid and hydrogen peroxide, grain size distribution, and presence of clay minerals. The results of these tests are presented in Tables 1.1 to 1.5. The Atterberg Limits, which include the Plastic Limit, Liquid Limit, and Shrinkage Limit, were determined for each soil to classify them and predict their behavior in different conditions. The Plasticity Index was computed for each soil, and the results are presented in Table 1.6. The Atterberg Limits were used to plot the soils in the Plasticity Chart, as shown in Figure 1.2. To control the workability of the soil mortars, a method for measuring their consistency was developed. The modified Vicat equipment was used to measure the consistency of the soil mortars, and a standard value of 10 mm was adopted as a workable, slightly dry soil mortar for all samples analyzed. The water content vs. consistency relationship was determined for each soil mortar prior to specimen fabrication, and the results are presented in Figures 1.4 to 1.9. The strength of the dry soils was measured by means of compressive tests carried out on 1" cubes and 10 cm cubes. Flexural tests on adobe bricks were also performed, and the results are summarized in Table 1.8. A preliminary study aimed at determining the effect of adding small quantities of dispersive agents on the compressive strength of 1" cubes was carried out at the University of California, Berkeley. The test results are listed in Table 1.9, and the effect of the additives on the water demand is presented in Table 1.10. The process known as "sleeping" was investigated, where the soil-water mixture is stored for a few days before the bricks are molded. The effect of adding sodium chloride, calcium chloride, lime, and cement to PUC soil was studied, and the results are summarized in Table 1.11. The research project aimed to improve the strength and seismic resistance of adobe masonry by understanding the properties of the soils used in its construction and developing strategies for improving its strength. The results of this investigation will lead to practical recommendations for building adobe dwellings with a significant increase in their seismic resistance.