Study of the mechanical and corrosion resistance properties of ferrocement

Abstract

Ferrocement is a lightweight, homogeneous and versatile structural material which is made as a composite of wire mesh and tightly wound skeletal steel impregnated with cement mortar. Ferrocement excels reinforced concrete system because of the minimal formwork and scaffolding requirement, possibility of casting elements on ground at site, fast erection and decrease in time of construction, and savings in the overall cost. Even though ferrocement has been used for various applications since 1800s, the technology is not properly standardized and unconventional local construction practices continue to prevail. Due to this and the poor workmanship, the durability of ferrocement structures has become an issue. Factors such as the corrosion of mesh and or the skeletal reinforcement, improper mix design etc. lead to deterioration of ferrocement structures. The major corrosion prevention methods used in reinforced concrete systems are application of coating to the steel such as epoxy or cement polymer composite (CPC) coatings and use of corrosion inhibitor in the cementitious matrix. The present study evaluates the possibility of adoption of these corrosion prevention strategies in ferrocement. The objective of the study is to analyse the flexural and corrosion resistance behaviour of four different types of ferrocement systems. The systems studied include ferrocement with normal welded mesh in normal cement mortar(WM); CPC coated weld mesh in normal cement mortar (CPC); normal weld mesh in cement mortar with corrosion inhibitor (WM CI); and CPC coated weld mesh in cement mortar with corrosion inhibitor (CPC CI). The corrosion analysis is done by using half cell potential measurements following ASTM C876-15 and flexural analysis by flexural strength test following IS 516: 1959. The results indicate that usage of both corrosion inhibitor and CPC coating can prominently increase the durability of ferrocement structures.