Engineered Cementitious Composites

Engineered Cementitious Composites (ECC) –

Material Properties, Mix Design and Structural Applications

Devendran R, Nevetha Ramesh, Ramesh Nadar

Student, Department of Civil Engineering, SRM University

Abstract- This study presents a brief overview on the recent progress in the research and development of Engineered Cementitious Composites (ECC). The material properties such as tensile characteristics, compressive strength, durability, permeability, self-healing capacity and seismic performance have been reviewed. The material constituents and mix design used to achieve the unique properties of ECC concrete have been discussed. The potential structural applications which utilize the special qualities of ECC are cited in this paper. A comparison

These specific qualities are based upon its material make up and the interactions with the surrounding environment experienced by it. The properties break down into the physical strength and interactions that ECC undergoes, along with the chemical reactions and characteristics that allow the process of self-healing to occur. These physical properties include remarkable tensile strength and ductility, which allow for one of the most important interactions in the concrete itself: micro-cracking. The process of micro cracking significantly increases the tensile strength and remains within a very low degree of permeability. This low permeability reduces the effects associated with the absorption of chemicals which include the corrosion of steel reinforcement and erosion of the concrete itself. This increases the repair cycle and lifespan of the concrete and the structure as a whole, while also creating the conditions that allow certain chemical reactions to occur that will help to heal or fill the cracks of the concrete

Crushing strengths of ECC can range from 20 to 95 MPa. The elastic modulus is of the range 15 to 34 GPa, which is typically lower than that for concrete and can be attributed to the absence of coarse aggregates. The post peak behaviour of ECC under compression tends to fall gently than that of high strength concrete and is accompanied by bulging of the specimen rather than a sudden crushing failure [8].

Durability performance of ECC

The Tight crack width control, exhibited even after extensive straining is a notable material property of ECC which will help remarkably in enhancing the durability of ECC structures in almost all aspects. This tight crack width is inherently controlled by the micromechanics principles of ECC. This tight crack width property has been demonstrated in many recent studies as the source for high durability of ECC, including permeability, corrosion resistance, chloride diffusion and freeze-thaw cycles [9].

2.3 Permeability and Freeze-Thaw