DESIGN OF PRECAST FERROCEMENT LINTELS

Abstract

Ferropement has been recognized as a material well suited for housing construction in developing countries because of its lighter weight, ease of construction, economy of materials, architectural flexibility and better utiliza-tion of human resources. Housing shortage is one of the major problems in India, where the need for cheaper housing has to be met with their limited natural resources. The steady increase of population and influx of migrants from the rural areas has led to an acute housing shortage in the cities. To meet the housing shortage in the country within a reasonable time frame, prefabrication of the full structure or some major components seems to be the only answer. Adoption of prefabrication leads to a product with a better finish strength and quality. The materials are efficiently utilized and enormous time and money savings are obtained. One such element is the lintel over door, windows and ventilators. At this level the pace of construction breaks due to the necessity of creating shuttering. Therefore, the possible use of precast ferrocement lintels needs to be studied. This study presents the results of an experimental and analytical investigation on the strength and behaviour of ferrocement rectangular and channel-shaped lintel elements tested in flexure. iv Tests have been conducted on eight rectangular and twenty channel-shaped ferrocement lintel elements up to failure. Analytical methods for determining their cracking strength, ultimate flexural strength, deflections and crack widths have been proposed and examined in the light of the test results. The spans have been varied from 0.6 m to 1.8 m and the loading considered is triangular and uniformly distributed. The correlation is found to be excellent and on the basis of the study it is recommended that the load factors of 2.5 and 1.8 may be used for the rectangular and channel sections respectively. The percentage economy varies from 25 percent to 10 percent for spans 0.6 m to 1.8 m for channel sections and 21 percent to 14 percent for spans 0.6 m to 1.0 m for rectangular sections.