Ferro-geopolymer composites for roofing – A sustainable approach for infrastructures

Abstract

Ferro-geopolymer is an upcoming building material that replaces the need for cement in construction practices and thereby reducing its carbon footprint. It is a composite consisting of geopolymer mortar matrix and wire meshes as reinforcement. The present study pioneers in the research of a prototype trapezoidal ferro-geopolymer roofing element under flexure. A total of nine specimens were cast, steam cured and subjected to third point loading. Three different spans of 2.5 m, 3.0 m and 3.4 m, and three different mesh types, (i) square welded mesh, (ii) square woven wire mesh, and (iii) hexagonal wire mesh, were the parameters considered for the study. Specimens reinforced with square welded wire mesh exhibited higher flexural strength compared with others, consequent to the additional strength imparted through the rigidity of welded connections. Maximum reduction in flexural strength of 20% and 32%, for specimens reinforced with square woven wire mesh and combination of hexagonal and square welded mesh, with respect to square welded wire mesh was observed for 3.0 m span beam elements. In addition, two analytical methods have been proposed to determine the ultimate flexural strength of ferro-geopolymer specimen and both methods were found to be in good agreement with the experimental results. The coefficient of variation of the predicted value of ultimate strength from the experimental value was obtained to be 9% for Method-I and 6% for Method-II.