This paper presents the main conclusions and recommendations of the Research Project "Earthen Buildings in Seismic Areas", developed in the Catholic University of Peru (PUC) in 1983. The most important soil characteristics from the viewpoint of the strength of adobe masonry are first studied. Subsequently, based on the acquired knowledge, the effect of some natural additives to the soil is investigated. Simple field tests, devised to identify the most adequate materials for adobe construction and to be easily transmitted to the potential adobe builder are finally proposed.

Se presentan los resultados de un estudio experimental en enlucidos de barro estabilizado sometidos a la acción erosiva de una lluvia simulada. Diferentes estabilizantes fueron utilizados, como los extractos obtenidos de las hojas de la tuna, una variedad de cactus; de las hojas y el tallo del plátano; y de las vainas del fruto del algarrobo. Con fines de comparación, se presentan adicionalmente resultados de ensayos de enlucidos de barro estabilizado con asfalto RC-250. Los resultados experimentales mostraron que la fisuración por contracción de secado es uno de los factores más importantes que afectan la durabilidad del enlucido frente a las lluvias. Se desarrolló un procedimiento para fabricar enlucidos resistentes a la lluvia en base a suelo, arena gruesa, paja y el estabilizante obtenido de la planta de la tuna.

Mud plasters or stuccos are commonly used to improve the moisture resistance of adobe structures. This study presents the results of a durability test program on mud plasters subjected to simulated rain. Different stabilizers were used, such as extracts from tuna leaves (a variety of cactus plants), banana leaves and stalks, locust bean tree pods, and manure. Test results of mud plasters stabilized with asphalt are presented for comparison. Experimental results showed that drying shrinkage cracking is one of the most important factors affecting the disintegration of soil stuccos. A procedure was developed to obtain a crack-resistant stucco composed of natural soil, coarse sand, straw, and a stabilizer extracted from the cactus plant. The stucco was found to be water-resistant.