Report # 107 : Reinforced Adobe

by Daniel Quiun

This is a reinforcement system for existing adobe houses, as well as an adaptation for new adobe houses, with the objective to prevent their collapse under severe earthquakes. An extensive experimental research project was developed between 1994 and 1999, with the financial support of GTZ of Germany, the administration of CERESIS, and the execution of the Catholic University of Peru (PUCP). Several reinforcement techniques were studied, and it was concluded that the most appropriate was to reinforce the walls with horizontal and vertical strips of wire mesh electrically welded, covered with mortar. The technique was applied in 1998 as pilot projects in 20 houses in 6 cities in Peru. Later in 1999-2000 it was extended to Chile, Bolivia, Ecuador and Venezuela. We had to wait for an earthquake to assess the effectiveness of the reinforcement. In the earthquake of June 23, 2001 (Mw=8.4), that affected the south of Peru, six reinforced adobe houses had no damage. Neighboring dwellings of unreinforced adobe suffered heavy damage or collapsed. This success motivated several reconstruction programs of new reinforced adobe houses in the Andean zone, in which the technique was improved and applied in more than 500 houses, which are described herein. Shaking table tests on the system used in the new houses at the Structures Laboratory of PUCP demonstrated that the reinforcement provided is effective for resisting severe earthquakes without collapse. The August 15, 2007 Pisco earthquake (Mw8.0), 200 km south of Lima, also provoked the collapse of many traditional adobe houses. In Ica province, 5 houses were reinforced in 1998 using the wire mesh strips, and all withstand the earthquake undamaged.

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Report # 52 : Adobe house

by Cesar Loaiza F., Marcial Blondet, Gianfranco Ottazzi

This is a traditional construction practice followed for over 200 years. Houses of this type can be found both in urban and rural areas in the coastal and highlands regions of Peru. Walls are made of adobe blocks laid in mud mortar. The roof structure is made of wood; it usually consists of timber beams with timber planks covered with a mud mortar overlay or with clay tiles or metal sheets. Houses of this type are mainly occupied by poor people. This construction is considered to be very vulnerable to earthquake effects.

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Report # 51 : Confined masonry houses

by Cesar Loaiza F., Marcial Blondet

This is the most common single-family housing construction practice followed both in urban and rural areas of Peru in the last 45 years. Confined masonry buildings consist of load-bearing unreinforced masonry walls made of clay brick units, confined by cast-in-place reinforced concrete tie columns and beams. These buildings do not have a complete load path in both horizontal directions required for adequate lateral load resistance. However, in spite of that, typical houses may show a good seismic performance.

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Report # 50 : Confined masonry building

by Cesar Loaiza F., Marcial Blondet

This multifamily housing construction type has been the most commonly used in the urban areas of Peru during the last 35 years. Confined masonry buildings consist of load-bearing unreinforced clay masonry walls confined by cast-in-place reinforced concrete tie columns and beams. Tie columns are cast after the construction of the masonry walls is complete and they are connected to the tie beams. Confined masonry walls have limited shear strength and ductility; however, buildings of this type typically have a good seismic resistance.

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