Reinforcement of Adobe Constructions with Toad Rush Mesh
Peru has a long history of mud constructions. The use of these techniques has been forgotten throughout time, and currently the adobe buildings lack a constructive system suitable for our seismic, economic and ecological characteristics. Current solutions to this problem, including the countrys normative, alter its natural characteristics and make it more expensive. To achieve a way of life that integrates cultural identity, dwelling, environment and health, a natural material of easy acquisition is studied: the toad rush (Juncus bufonius L.) It is a plant that grows in humid areas of the country, between 0 and 4 000 AMSL, in order to address its use as reinforcement in the walls of adobe, based on structural proposals approved in Peru. An experimental methodology has been used under the modality of trial and error. The study was performed in three stages; in the first one, its elasticity coefficient and resistance to traction was determined in laboratory tests. The analysis were performed on simple fibers and braids (of up to 6 fibers), finding the following results: elasticity modulus = 36 kPa with 5% strain, maximum tension stress = 745 N in both directions with 12% elongation. Using these data, an orthogonal mesh of toad rushes, with 0.030 m of separation between braids, was designed to be attached to an adobe wall. This mesh was subjected to a test of horizontal impact, applying 84.49 MPa as a maximum force. In a third stage an adobe module of 2.40 x 2.40 x 2.40 m reinforced with the mesh was subjected to a mechanical seismic simulation test, supporting 26.1 kN without the mesh suffering any damage. As a last test, to comply with the requirements laid down in annex N°1 of the E.080 RNE of the Peruvian standard, a real scale module (2.40 x 2.40 x 2.40 m), was subjected to a cyclic test at the CISMID-UNI laboratory. The results showed that under a distortion from 1/1100 to 1/500 micro cracks were generated in the walls. Under a distortion of 1/400, 0.005 m cracks occurred at the bottom of the north side of the model and under a distortion of 1/280 the model suffered the detachment of the plaster of the lintel, without any damage to the mesh. All the tests allowed for the conclusion that the toad rush (Juncus bufonius L.) is a material that, used as a mesh, can be used as reinforcement in adobe buildings. It is elastic and resistant to traction. It has as an advantage that it is very accessible, known throughout the country and easy to work with. The tests allowed us to proof the resistance of the toad rush mesh, in spite of the features of the adobe not conforming to the Peruvian standard E.080 RNE. We conclude that: it is feasible to use a mesh of toad rush (Juncus bufonius L.) as reinforcement in adobe buildings.
Khosrow Ghavami, Normando Perazzo Barbosa, Ulisses Targino Bezerra and Alexandr Zhemchuzhnikov
M. T. L. Méndez et al., "Reinforcement of Adobe Constructions with Toad Rush Mesh", Key Engineering Materials, Vol. 600, pp. 208-214, 2014