STUDY OF MESH OVERLAPS AND JOINT EFFICIENCY IN FERROCEMENT ELEMENTS

Abstract

Ferrocement a composite material where the matrix is reinforced with layers of continuous and relatively small diameter mesh of metallic or other suitable materials, has well established itself as a versatile construction material possessing almost all the essential qualities'of a good structural material capable of giving safe and serviceable structural elements. A cost analysis reveals that the use of ferrocement for building construction will lead to a substan-tial reduction in the cost of construction compared to the use of conventional construction materials. Ferrocement, because of, its simple construction technique and use of local materials seems to be an appropriate solution for providing economic shelters to low-income groups. However, the ultimate economic applications of the material for low-cost housing lies in the mass production of building components in prefabricated form in standard sizes which can be easily handled, transported to the site and easily placed and joined together. In actual ferrocement structures, meshes have to be overlapped. It is also quite feasible to join pre-fabricated units in-situ by overlapping the projected reinforcement from the corresponding units by the amount required to develop the requisite strength through bond at the joint under the given condition of loading. This important aspect of mesh overlap has been eluding scientific investigations. The present investigation is attempted iv to study the effect of mesh overlaps under different condition of loadings, viz. (i) Direct tension, (ii) Axial compression (iii) Flexure, and (iv) Hoop tension. On the basis of the experimental results, a theoretical relation is proposed which directly gives the mesh overlap. The result predicted by the proposed relation has been used to join pre-fabricated ribbed units intended to act as floors/roofings. The jointed slabs have been subjected to uniformly distributed load on -simplg support and the efficiency of joints studied., Experimental results show that the method of jointing different units adopted is efficient. The investigation also establishes feasibility of producing ferrocement flooring/flat roofing units on a industrial scale. The 'investigation further establishes that other ferrocement building components can also be joined like-way. In other words, the investigation establishes the feasibility of factory made ferrocement house which will be a striking solution to providing economic houses at a greater pace and solving the ever increasing housing problem - a challen-ging global problem.